diff --git a/smart-contract/hyperledger-fabric/v2/java/Dockerfile b/smart-contract/hyperledger-fabric/v2/java/Dockerfile
index f792562..e7dc040 100644
--- a/smart-contract/hyperledger-fabric/v2/java/Dockerfile
+++ b/smart-contract/hyperledger-fabric/v2/java/Dockerfile
@@ -6,6 +6,7 @@ COPY buildSrc/ buildSrc/
 COPY build.gradle.kts ./ 
 COPY gradle.properties ./
 COPY specs/ ./specs/
+COPY libs/ ./libs/
 
 RUN gradle --no-daemon shadowJar
 
diff --git a/smart-contract/hyperledger-fabric/v2/java/README.md b/smart-contract/hyperledger-fabric/v2/java/README.md
index 5a3aed0..3ec87c9 100644
--- a/smart-contract/hyperledger-fabric/v2/java/README.md
+++ b/smart-contract/hyperledger-fabric/v2/java/README.md
@@ -15,6 +15,16 @@ However, note that normally, you do not need to locally build the chaincode.
 The [test network](../../../../test-network/README.adoc) will build generate this JAR as part of a [dockerized](https://www.docker.com/) build process.
 Build directly only if you know what you are doing.
 
+## Development
+
+You most likely do not want to build with OpenJML for local development, eg in your IDE.
+To disable OpenJML, simply set the `withoutOpenJML` Gradle property to `true`.
+For example, in `gradle.properties`:
+
+```properties
+withoutOpenJML = "true"
+```
+
 
 ## License
 
diff --git a/smart-contract/hyperledger-fabric/v2/java/build.gradle.kts b/smart-contract/hyperledger-fabric/v2/java/build.gradle.kts
index cae3f95..d9cc825 100644
--- a/smart-contract/hyperledger-fabric/v2/java/build.gradle.kts
+++ b/smart-contract/hyperledger-fabric/v2/java/build.gradle.kts
@@ -1,9 +1,8 @@
 /* Originally based on https://github.com/mingyang91/openjml-template */
 
-import com.diffplug.gradle.spotless.SpotlessExtension
 import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
 import hu.bme.mit.ftsrg.openjmlhelper.*
-import java.io.File
+import org.gradle.api.tasks.testing.logging.TestLogEvent
 
 val openJMLDir = layout.projectDirectory.dir(".openjml")
 val openJMLJavaHomeDir = openJMLDir.dir("jdk")
@@ -12,13 +11,18 @@ val downloadDir = layout.buildDirectory.dir("tmp/download")
 val jmlavac = openJMLJavaHomeDir.file("bin/jmlavac")
 val jmlava = openJMLJavaHomeDir.file("bin/jmlava")
 
+val withoutOpenJML: String? by project
+val noOpenJML: Boolean = withoutOpenJML != null && withoutOpenJML.toBoolean()
+
 plugins {
   application
   id("com.github.johnrengelman.shadow") version "7.1.2"
   id("com.diffplug.spotless") version "6.19.0"
 }
 
-group = "hu.bme.mit.ftsrg.tpcc"
+// java { toolchain { languageVersion.set(JavaLanguageVersion.of(17) } }
+
+group = "hu.bme.mit.ftsrg.chaincode.tpcc"
 
 version = "0.1.0"
 
@@ -28,7 +32,9 @@ repositories {
 }
 
 dependencies {
-  implementation("ch.qos.logback:logback-classic:1.4.8")
+  implementation("ch.qos.logback:logback-core:1.5.6")
+  implementation("ch.qos.logback:logback-classic:1.5.6")
+  implementation("org.slf4j:slf4j-api:2.0.13")
   implementation("com.google.code.gson:gson:2.10.1")
   implementation("com.jcabi:jcabi-aspects:0.25.1")
   implementation("org.aspectj:aspectjrt:1.9.19")
@@ -37,6 +43,7 @@ dependencies {
   implementation("org.hyperledger.fabric:fabric-protos:0.3.0")
   implementation("org.json:json:20230227")
   implementation("org.projectlombok:lombok:1.18.28")
+  implementation(files("libs/hypernate-0.1.0.jar"))
   // Included also as implementation dependency so shadow will package it
   implementation(files("$openJMLDir/jmlruntime.jar"))
 
@@ -49,73 +56,83 @@ dependencies {
 application { mainClass.set("org.hyperledger.fabric.contract.ContractRouter") }
 
 tasks.named<ShadowJar>("shadowJar") {
-  if (System.getenv("NO_JML") == "") dependsOn(tasks.named("initOpenJML"))
-
   archiveBaseName.set("chaincode")
   archiveClassifier.set("")
   archiveVersion.set("")
 }
 
-tasks.named<Test>("test") { useJUnitPlatform() }
+tasks.register("initOpenJML") {
+  val openJMLVersion: String by project
 
-tasks.test {
-  java {
-    executable = "$openJMLDir/bin/jmlava"
-    jvmArgs = listOf("-Dorg.jmlspecs.openjml.rac=exception")
-  }
+  val zipFile: File = downloadDir.get().file("openjml.zip").asFile
+  downloadOpenJML(openJMLVersion, zipFile, logger)
+  extractOpenJML(zipFile, openJMLDir, logger)
+
+  // `jmlavac' is what we call `javac' that is actually
+  // OpenJML's javac; likewise, `jmlava' is a wrapper for `java' with
+  // OpenJML already in the classpath
+  generateJmlavac(jmlavac.asFile, openJMLJavaHomeDir, logger)
+  replaceJavac(openJMLJavaHomeDir, jmlavac.asFile, logger)
+  generateJmlava(jmlava.asFile, openJMLJavaHomeDir, logger)
+  replaceJava(openJMLJavaHomeDir, jmlava.asFile, logger)
+  logger.lifecycle("✅ OpenJML successfully initialized in $openJMLDir")
 }
 
-// java {
-//   sourceCompatibility = JavaVersion.VERSION_17
-//   targetCompatibility = JavaVersion.VERSION_17
-// }
+if (!noOpenJML) {
+  tasks.named<ShadowJar>("shadowJar") { dependsOn(tasks.named("initOpenJML")) }
+
+  tasks.test {
+    java {
+      executable = "$openJMLDir/bin/jmlava"
+      jvmArgs = listOf("-Dorg.jmlspecs.openjml.rac=exception")
+    }
+  }
 
-tasks.withType<JavaCompile>().configureEach {
-  // Only when not compiling because of Spotless
-  if (!gradle.startParameter.taskNames.any { it.contains("spotlessApply") } &&
-      System.getenv("NO_JML") == "") {
+  tasks.withType<JavaCompile>().configureEach {
     dependsOn(tasks.named("initOpenJML"))
-    val mode =
-        when (System.getenv("JML_MODE")) {
-          "esc" -> "esc"
-          else -> "rac"
-        }
-    options.isFork = true
-    options.compilerArgs.addAll(
-        listOf(
-            "-jml", "-$mode", "-timeout", "30", "--nullable-by-default", "--specs-path", "specs/"))
-    options.forkOptions.javaHome = openJMLJavaHomeDir.asFile
+    // Only when not compiling because of Spotless
+    if (!gradle.startParameter.taskNames.any { it.contains("spotlessApply") }) {
+      val mode =
+          when (System.getenv("JML_MODE")) {
+            "esc" -> "esc"
+            else -> "rac"
+          }
+      options.isFork = true
+      options.compilerArgs.addAll(
+          listOf(
+              "-jml",
+              "-$mode",
+              "-timeout",
+              "30",
+              "--nullable-by-default",
+              "--specs-path",
+              "specs/"))
+      options.forkOptions.javaHome = openJMLJavaHomeDir.asFile
+    }
   }
 }
 
-configure<SpotlessExtension> {
+tasks.test {
+  useJUnitPlatform()
+  testLogging {
+    showExceptions = true
+    events = setOf(TestLogEvent.FAILED, TestLogEvent.PASSED, TestLogEvent.SKIPPED)
+  }
+}
+
+spotless {
   java {
     importOrder()
     removeUnusedImports()
     googleJavaFormat()
     formatAnnotations()
     toggleOffOn()
+    licenseHeader("/* SPDX-License-Identifier: Apache-2.0 */")
   }
   kotlin {
     target("src/*/kotlin/**/*.kt", "buildSrc/src/*/kotlin/**/*.kt")
     ktfmt()
+    licenseHeader("/* SPDX-License-Identifier: Apache-2.0 */")
   }
   kotlinGradle { ktfmt() }
 }
-
-tasks.register("initOpenJML") {
-  val openJMLVersion: String by project
-
-  val zipFile: File = downloadDir.get().file("openjml.zip").asFile
-  downloadOpenJML(openJMLVersion, zipFile, logger)
-  extractOpenJML(zipFile, openJMLDir, logger)
-
-  // `jmlavac' is what we call `javac' that is actually
-  // OpenJML's javac; likewise, `jmlava' is a wrapper for `java' with
-  // OpenJML already in the classpath
-  generateJmlavac(jmlavac.asFile, openJMLJavaHomeDir, logger)
-  replaceJavac(openJMLJavaHomeDir, jmlavac.asFile, logger)
-  generateJmlava(jmlava.asFile, openJMLJavaHomeDir, logger)
-  replaceJava(openJMLJavaHomeDir, jmlava.asFile, logger)
-  logger.lifecycle("✅ OpenJML successfully initialized in $openJMLDir")
-}
diff --git a/smart-contract/hyperledger-fabric/v2/java/buildSrc/src/main/kotlin/hu/bme/mit/ftsrg/openjmlhelper/OpenJMLHelper.kt b/smart-contract/hyperledger-fabric/v2/java/buildSrc/src/main/kotlin/hu/bme/mit/ftsrg/openjmlhelper/OpenJMLHelper.kt
index d2ff6f9..26cbc27 100644
--- a/smart-contract/hyperledger-fabric/v2/java/buildSrc/src/main/kotlin/hu/bme/mit/ftsrg/openjmlhelper/OpenJMLHelper.kt
+++ b/smart-contract/hyperledger-fabric/v2/java/buildSrc/src/main/kotlin/hu/bme/mit/ftsrg/openjmlhelper/OpenJMLHelper.kt
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 */
 package hu.bme.mit.ftsrg.openjmlhelper
 
 import java.io.File
diff --git a/smart-contract/hyperledger-fabric/v2/java/gradle.properties b/smart-contract/hyperledger-fabric/v2/java/gradle.properties
index 11e657e..a07d4e8 100644
--- a/smart-contract/hyperledger-fabric/v2/java/gradle.properties
+++ b/smart-contract/hyperledger-fabric/v2/java/gradle.properties
@@ -1 +1,2 @@
 openJMLVersion = 0.17.0-alpha-15
+withoutOpenJML = false
\ No newline at end of file
diff --git a/smart-contract/hyperledger-fabric/v2/java/libs/hypernate-0.1.0.jar b/smart-contract/hyperledger-fabric/v2/java/libs/hypernate-0.1.0.jar
new file mode 100644
index 0000000..a817129
Binary files /dev/null and b/smart-contract/hyperledger-fabric/v2/java/libs/hypernate-0.1.0.jar differ
diff --git a/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/TPCC.jml b/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/TPCC.jml
index 7f62c44..0197780 100644
--- a/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/TPCC.jml
+++ b/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/TPCC.jml
@@ -2,8 +2,8 @@
 
 package hu.bme.mit.ftsrg.chaincode.tpcc;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.exception.EntityExistsException;
-import hu.bme.mit.ftsrg.chaincode.dataaccess.exception.EntityNotFoundException;
+import hu.bme.mit.ftsrg.hypernate.entity.EntityExistsException;
+import hu.bme.mit.ftsrg.hypernate.entity.EntityNotFoundException;
 import hu.bme.mit.ftsrg.chaincode.tpcc.data.input.*;
 import hu.bme.mit.ftsrg.chaincode.tpcc.data.output.*;
 import hu.bme.mit.ftsrg.chaincode.tpcc.middleware.TPCCContext;
@@ -57,4 +57,9 @@ public final class TPCC implements ContractInterface {
     @*/
   private StockLevelOutput stockLevel(final TPCCContext ctx, final StockLevelInput input)
       throws EntityNotFoundException, NotFoundException;
+
+  /*@
+    @ requires c_id < 2;
+    @*/
+  public String OJMLTEST__getCustomer(final TPCCContext ctx, final int c_w_id, final int c_d_id, final int c_id);
 }
diff --git a/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Customer.jml b/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Customer.jml
index 201bddd..fa4229e 100644
--- a/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Customer.jml
+++ b/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Customer.jml
@@ -2,9 +2,9 @@
 
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.entity;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.SerializableEntityBase;
+import hu.bme.mit.ftsrg.hypernate.entity.Entity;
 
-public class Customer extends SerializableEntityBase<Customer> {
+public class Customer implements Entity<Customer> {
 
   public /*@ pure @*/ int getC_id();
 
diff --git a/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/District.jml b/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/District.jml
index 42aeab7..49de7f4 100644
--- a/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/District.jml
+++ b/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/District.jml
@@ -2,9 +2,9 @@
 
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.entity;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.SerializableEntityBase;
+import hu.bme.mit.ftsrg.hypernate.entity.Entity;
 
-public final class District extends SerializableEntityBase<District> {
+public final class District implements Entity<District> {
 
   public /*@ pure @*/ int getD_id();
 
diff --git a/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/History.jml b/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/History.jml
index 9feddb3..8c872c0 100644
--- a/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/History.jml
+++ b/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/History.jml
@@ -2,9 +2,9 @@
 
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.entity;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.SerializableEntityBase;
+import hu.bme.mit.ftsrg.hypernate.entity.Entity;
 
-public final class History extends SerializableEntityBase<History> {
+public final class History implements Entity<History> {
 
   public /*@ pure @*/ int getH_c_id();
 
diff --git a/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Item.jml b/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Item.jml
index 471e37d..f7e3718 100644
--- a/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Item.jml
+++ b/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Item.jml
@@ -2,9 +2,9 @@
 
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.entity;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.SerializableEntityBase;
+import hu.bme.mit.ftsrg.hypernate.entity.Entity;
 
-public final class Item extends SerializableEntityBase<Item> {
+public final class Item implements Entity<Item> {
 
   public /*@ pure @*/ int getI_id();
 
diff --git a/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/NewOrder.jml b/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/NewOrder.jml
index a90b8c9..3dedf03 100644
--- a/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/NewOrder.jml
+++ b/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/NewOrder.jml
@@ -2,9 +2,9 @@
 
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.entity;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.SerializableEntityBase;
+import hu.bme.mit.ftsrg.hypernate.entity.Entity;
 
-public final class NewOrder extends SerializableEntityBase<NewOrder> {
+public final class NewOrder implements Entity<NewOrder> {
 
   public /*@ pure @*/ int getNo_o_id();
 
diff --git a/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Order.jml b/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Order.jml
index 17eb5ee..3136a5a 100644
--- a/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Order.jml
+++ b/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Order.jml
@@ -2,9 +2,9 @@
 
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.entity;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.SerializableEntityBase;
+import hu.bme.mit.ftsrg.hypernate.entity.Entity;
 
-public final class Order extends SerializableEntityBase<Order> {
+public final class Order implements Entity<Order> {
 
   public /*@ pure @*/ int getO_id();
 
diff --git a/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/OrderLine.jml b/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/OrderLine.jml
index 74ff6ef..31cc573 100644
--- a/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/OrderLine.jml
+++ b/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/OrderLine.jml
@@ -2,9 +2,9 @@
 
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.entity;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.SerializableEntityBase;
+import hu.bme.mit.ftsrg.hypernate.entity.Entity;
 
-public final class OrderLine extends SerializableEntityBase<OrderLine> {
+public final class OrderLine implements Entity<OrderLine> {
 
   public /*@ pure @*/ int getOl_o_id();
 
diff --git a/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Stock.jml b/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Stock.jml
index aea077f..38f4643 100644
--- a/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Stock.jml
+++ b/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Stock.jml
@@ -2,9 +2,9 @@
 
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.entity;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.SerializableEntityBase;
+import hu.bme.mit.ftsrg.hypernate.entity.Entity;
 
-public final class Stock extends SerializableEntityBase<Stock> {
+public final class Stock implements Entity<Stock> {
 
   public /*@ pure @*/ int getS_i_id();
 
diff --git a/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Warehouse.jml b/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Warehouse.jml
index 0b4f00b..7ec63a6 100644
--- a/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Warehouse.jml
+++ b/smart-contract/hyperledger-fabric/v2/java/specs/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Warehouse.jml
@@ -2,9 +2,9 @@
 
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.entity;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.SerializableEntityBase;
+import hu.bme.mit.ftsrg.hypernate.entity.Entity;
 
-public class Warehouse extends SerializableEntityBase<Warehouse> {
+public class Warehouse implements Entity<Warehouse> {
 
   public /*@ pure @*/ int getW_id();
 
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/MethodLogger.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/MethodLogger.java
index fc42e92..d6f830f 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/MethodLogger.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/MethodLogger.java
@@ -1,6 +1,7 @@
+/* SPDX-License-Identifier: Apache-2.0 */
 package hu.bme.mit.ftsrg.chaincode;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.SerializableEntity;
+import hu.bme.mit.ftsrg.hypernate.entity.Entity;
 import java.util.ArrayList;
 import java.util.List;
 import org.hyperledger.fabric.contract.Context;
@@ -42,7 +43,7 @@ public String generateParamsString(final Context ctx, final int... params) {
     return "%s,%s".formatted(ctx.toString(), generateParamsString(params));
   }
 
-  public <Type extends SerializableEntity<Type>> String generateParamsString(
+  public <Type extends Entity<Type>> String generateParamsString(
       final Context ctx, final Type obj) {
     return "%s,%s".formatted(ctx.toString(), obj.toString());
   }
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/ChaincodeStubMiddlewareBase.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/ChaincodeStubMiddlewareBase.java
deleted file mode 100644
index 596595c..0000000
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/ChaincodeStubMiddlewareBase.java
+++ /dev/null
@@ -1,262 +0,0 @@
-/* SPDX-License-Identifier: Apache-2.0 */
-
-package hu.bme.mit.ftsrg.chaincode.dataaccess;
-
-import java.time.Instant;
-import java.util.List;
-import java.util.Map;
-import org.hyperledger.fabric.protos.peer.ChaincodeEvent;
-import org.hyperledger.fabric.protos.peer.SignedProposal;
-import org.hyperledger.fabric.shim.Chaincode.Response;
-import org.hyperledger.fabric.shim.ChaincodeStub;
-import org.hyperledger.fabric.shim.ledger.CompositeKey;
-import org.hyperledger.fabric.shim.ledger.KeyModification;
-import org.hyperledger.fabric.shim.ledger.KeyValue;
-import org.hyperledger.fabric.shim.ledger.QueryResultsIterator;
-import org.hyperledger.fabric.shim.ledger.QueryResultsIteratorWithMetadata;
-
-/**
- * Base class for {@link ChaincodeStub} middlewares.
- *
- * <p>This class provides the same interface as {@link ChaincodeStub}, but under the hood it
- * maintains a reference to another {@link ChaincodeStub} and delegates all calls to that. You can
- * override any method in this class to inject your custom behaviour, such as logging, access
- * control, caching, etc.
- */
-public abstract class ChaincodeStubMiddlewareBase implements ChaincodeStub {
-
-  public ChaincodeStubMiddlewareBase(final ChaincodeStub nextLayer) {
-    this.nextLayer = nextLayer;
-  }
-
-  protected final ChaincodeStub nextLayer;
-
-  @Override
-  public List<byte[]> getArgs() {
-    return this.nextLayer.getArgs();
-  }
-
-  @Override
-  public List<String> getStringArgs() {
-    return this.nextLayer.getStringArgs();
-  }
-
-  @Override
-  public String getFunction() {
-    return this.nextLayer.getFunction();
-  }
-
-  @Override
-  public List<String> getParameters() {
-    return this.nextLayer.getParameters();
-  }
-
-  @Override
-  public String getTxId() {
-    return this.nextLayer.getTxId();
-  }
-
-  @Override
-  public String getChannelId() {
-    return this.nextLayer.getChannelId();
-  }
-
-  @Override
-  public Response invokeChaincode(
-      final String chaincodeName, final List<byte[]> args, final String channel) {
-    return this.nextLayer.invokeChaincode(chaincodeName, args, channel);
-  }
-
-  @Override
-  public byte[] getState(final String key) {
-    return this.nextLayer.getState(key);
-  }
-
-  @Override
-  public byte[] getStateValidationParameter(final String key) {
-    return this.nextLayer.getStateValidationParameter(key);
-  }
-
-  @Override
-  public void putState(final String key, final byte[] value) {
-    this.nextLayer.putState(key, value);
-  }
-
-  @Override
-  public void setStateValidationParameter(final String key, final byte[] value) {
-    this.nextLayer.setStateValidationParameter(key, value);
-  }
-
-  @Override
-  public void delState(final String key) {
-    this.nextLayer.delState(key);
-  }
-
-  @Override
-  public QueryResultsIterator<KeyValue> getStateByRange(
-      final String startKey, final String endKey) {
-    return this.nextLayer.getStateByRange(startKey, endKey);
-  }
-
-  @Override
-  public QueryResultsIteratorWithMetadata<KeyValue> getStateByRangeWithPagination(
-      final String startKey, final String endKey, final int pageSize, final String bookmark) {
-    return this.nextLayer.getStateByRangeWithPagination(startKey, endKey, pageSize, bookmark);
-  }
-
-  @Override
-  public QueryResultsIterator<KeyValue> getStateByPartialCompositeKey(final String compositeKey) {
-    return this.nextLayer.getStateByPartialCompositeKey(compositeKey);
-  }
-
-  @Override
-  public QueryResultsIterator<KeyValue> getStateByPartialCompositeKey(
-      final String objectType, final String... attributes) {
-    return this.nextLayer.getStateByPartialCompositeKey(objectType, attributes);
-  }
-
-  @Override
-  public QueryResultsIterator<KeyValue> getStateByPartialCompositeKey(
-      final CompositeKey compositeKey) {
-    return this.nextLayer.getStateByPartialCompositeKey(compositeKey);
-  }
-
-  @Override
-  public QueryResultsIteratorWithMetadata<KeyValue> getStateByPartialCompositeKeyWithPagination(
-      final CompositeKey compositeKey, final int pageSize, final String bookmark) {
-    return this.nextLayer.getStateByPartialCompositeKeyWithPagination(
-        compositeKey, pageSize, bookmark);
-  }
-
-  @Override
-  public CompositeKey createCompositeKey(final String objectType, final String... attributes) {
-    return this.nextLayer.createCompositeKey(objectType, attributes);
-  }
-
-  @Override
-  public CompositeKey splitCompositeKey(final String compositeKey) {
-    return this.nextLayer.splitCompositeKey(compositeKey);
-  }
-
-  @Override
-  public QueryResultsIterator<KeyValue> getQueryResult(final String query) {
-    return this.nextLayer.getQueryResult(query);
-  }
-
-  @Override
-  public QueryResultsIteratorWithMetadata<KeyValue> getQueryResultWithPagination(
-      final String query, final int pageSize, final String bookmark) {
-    return this.nextLayer.getQueryResultWithPagination(query, pageSize, bookmark);
-  }
-
-  @Override
-  public QueryResultsIterator<KeyModification> getHistoryForKey(final String key) {
-    return this.nextLayer.getHistoryForKey(key);
-  }
-
-  @Override
-  public byte[] getPrivateData(final String collection, final String key) {
-    return this.nextLayer.getPrivateData(collection, key);
-  }
-
-  @Override
-  public byte[] getPrivateDataHash(final String collection, final String key) {
-    return this.nextLayer.getPrivateDataHash(collection, key);
-  }
-
-  @Override
-  public byte[] getPrivateDataValidationParameter(final String collection, final String key) {
-    return this.nextLayer.getPrivateDataValidationParameter(collection, key);
-  }
-
-  @Override
-  public void putPrivateData(final String collection, final String key, final byte[] value) {
-    this.nextLayer.putPrivateData(collection, key, value);
-  }
-
-  @Override
-  public void setPrivateDataValidationParameter(
-      final String collection, final String key, final byte[] value) {
-    this.nextLayer.setPrivateDataValidationParameter(collection, key, value);
-  }
-
-  @Override
-  public void delPrivateData(final String collection, final String key) {
-    this.nextLayer.delPrivateData(collection, key);
-  }
-
-  @Override
-  public void purgePrivateData(final String collection, final String key) {
-    this.nextLayer.purgePrivateData(collection, key);
-  }
-
-  @Override
-  public QueryResultsIterator<KeyValue> getPrivateDataByRange(
-      final String collection, final String startKey, final String endKey) {
-    return this.nextLayer.getPrivateDataByRange(collection, startKey, endKey);
-  }
-
-  @Override
-  public QueryResultsIterator<KeyValue> getPrivateDataByPartialCompositeKey(
-      final String collection, final String compositeKey) {
-    return this.nextLayer.getPrivateDataByPartialCompositeKey(collection, compositeKey);
-  }
-
-  @Override
-  public QueryResultsIterator<KeyValue> getPrivateDataByPartialCompositeKey(
-      final String collection, final CompositeKey compositeKey) {
-    return this.nextLayer.getPrivateDataByPartialCompositeKey(collection, compositeKey);
-  }
-
-  @Override
-  public QueryResultsIterator<KeyValue> getPrivateDataByPartialCompositeKey(
-      final String collection, final String objectType, final String... attributes) {
-    return this.nextLayer.getPrivateDataByPartialCompositeKey(collection, objectType, attributes);
-  }
-
-  @Override
-  public QueryResultsIterator<KeyValue> getPrivateDataQueryResult(
-      final String collection, final String query) {
-    return this.nextLayer.getPrivateDataQueryResult(collection, query);
-  }
-
-  @Override
-  public void setEvent(final String name, final byte[] payload) {
-    this.nextLayer.setEvent(name, payload);
-  }
-
-  @Override
-  public ChaincodeEvent getEvent() {
-    return this.nextLayer.getEvent();
-  }
-
-  @Override
-  public SignedProposal getSignedProposal() {
-    return this.nextLayer.getSignedProposal();
-  }
-
-  @Override
-  public Instant getTxTimestamp() {
-    return this.nextLayer.getTxTimestamp();
-  }
-
-  @Override
-  public byte[] getCreator() {
-    return this.nextLayer.getCreator();
-  }
-
-  @Override
-  public Map<String, byte[]> getTransient() {
-    return this.nextLayer.getTransient();
-  }
-
-  @Override
-  public byte[] getBinding() {
-    return this.nextLayer.getBinding();
-  }
-
-  @Override
-  public String getMspId() {
-    return this.nextLayer.getMspId();
-  }
-}
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/ContextWithRegistry.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/ContextWithRegistry.java
deleted file mode 100644
index ee3f81d..0000000
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/ContextWithRegistry.java
+++ /dev/null
@@ -1,22 +0,0 @@
-package hu.bme.mit.ftsrg.chaincode.dataaccess;
-
-import org.hyperledger.fabric.contract.Context;
-import org.hyperledger.fabric.shim.ChaincodeStub;
-
-/**
- * Fabric's original context extended with a {@link Registry}.
- *
- * <p>The registry can be used to manage entities.
- */
-public class ContextWithRegistry extends Context {
-
-  private final Registry registry = new RegistryImpl();
-
-  public ContextWithRegistry(final ChaincodeStub stub) {
-    super(stub);
-  }
-
-  public Registry getRegistry() {
-    return registry;
-  }
-}
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/EntityFactory.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/EntityFactory.java
deleted file mode 100644
index 2fb5676..0000000
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/EntityFactory.java
+++ /dev/null
@@ -1,15 +0,0 @@
-package hu.bme.mit.ftsrg.chaincode.dataaccess;
-
-/**
- * Minimal interface to allow entities to return factories that produce them.
- *
- * @param <Type> the entity's type
- */
-public interface EntityFactory<Type extends SerializableEntity<Type>> {
-  /**
-   * Simply gives a new, empty instance of the entity of type <code>Type</code>.
-   *
-   * @return a new, empty entity instance
-   */
-  Type create();
-}
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/KeyPart.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/KeyPart.java
deleted file mode 100644
index bd75bfe..0000000
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/KeyPart.java
+++ /dev/null
@@ -1,19 +0,0 @@
-package hu.bme.mit.ftsrg.chaincode.dataaccess;
-
-import java.lang.annotation.ElementType;
-import java.lang.annotation.Retention;
-import java.lang.annotation.RetentionPolicy;
-import java.lang.annotation.Target;
-
-/**
- * Marks a field of a {@link SerializableEntity} as a primary key part.
- *
- * <p>Add this annotation to all fields you wish to have as primary keys. {@link
- * SerializableEntityBase#getKeyParts()} returns an array constructed of these, with additional
- * padding.
- *
- * @see SerializableEntity
- */
-@Retention(RetentionPolicy.RUNTIME)
-@Target(ElementType.FIELD)
-public @interface KeyPart {}
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/Registry.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/Registry.java
deleted file mode 100644
index 1456e38..0000000
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/Registry.java
+++ /dev/null
@@ -1,47 +0,0 @@
-package hu.bme.mit.ftsrg.chaincode.dataaccess;
-
-import hu.bme.mit.ftsrg.chaincode.dataaccess.exception.EntityExistsException;
-import hu.bme.mit.ftsrg.chaincode.dataaccess.exception.EntityNotFoundException;
-import java.util.Comparator;
-import java.util.List;
-import org.hyperledger.fabric.contract.Context;
-
-public interface Registry {
-
-  <Type extends SerializableEntity<Type>> void create(Context ctx, Type entity)
-      throws EntityExistsException;
-
-  <Type extends SerializableEntity<Type>> void update(Context ctx, Type entity)
-      throws EntityNotFoundException;
-
-  <Type extends SerializableEntity<Type>> void delete(Context ctx, Type entity)
-      throws EntityNotFoundException;
-
-  <Type extends SerializableEntity<Type>> Type read(Context ctx, Type target)
-      throws EntityNotFoundException;
-
-  <Type extends SerializableEntity<Type>> List<Type> readAll(Context ctx, Type template);
-
-  <Type extends SerializableEntity<Type>> SelectionBuilder<Type> select(Context ctx, Type template);
-
-  interface SelectionBuilder<Type extends SerializableEntity<Type>> {
-    SelectionBuilder<Type> matching(Matcher<Type> matcher);
-
-    SelectionBuilder<Type> sortedBy(Comparator<Type> comparator);
-
-    SelectionBuilder<Type> descending();
-
-    List<Type> get();
-
-    Type getFirst();
-  }
-
-  interface Matcher<Type extends SerializableEntity<Type>> {
-    boolean match(Type entity);
-  }
-
-  enum Order {
-    ASCENDING,
-    DESCENDING
-  }
-}
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/RegistryImpl.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/RegistryImpl.java
deleted file mode 100644
index 325efb2..0000000
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/RegistryImpl.java
+++ /dev/null
@@ -1,210 +0,0 @@
-package hu.bme.mit.ftsrg.chaincode.dataaccess;
-
-import com.jcabi.aspects.Loggable;
-import hu.bme.mit.ftsrg.chaincode.MethodLogger;
-import hu.bme.mit.ftsrg.chaincode.dataaccess.exception.EntityExistsException;
-import hu.bme.mit.ftsrg.chaincode.dataaccess.exception.EntityNotFoundException;
-import java.util.*;
-import org.hyperledger.fabric.contract.Context;
-import org.hyperledger.fabric.shim.ledger.CompositeKey;
-import org.hyperledger.fabric.shim.ledger.KeyValue;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-@Loggable(Loggable.DEBUG) // FIXME how to configure AspectJ with OpenJML and Gradle?
-public class RegistryImpl implements Registry {
-
-  private static final Logger logger = LoggerFactory.getLogger(RegistryImpl.class);
-
-  private static final MethodLogger methodLogger = new MethodLogger(logger, "RegistryImpl");
-
-  public RegistryImpl() {}
-
-  private <Type extends SerializableEntity<Type>> String getKey(final Context ctx, final Type obj) {
-    final String paramsString = methodLogger.generateParamsString(ctx, obj);
-    methodLogger.logStart("getKey", paramsString);
-
-    final CompositeKey compositeKey =
-        ctx.getStub().createCompositeKey(obj.getType(), obj.getKeyParts());
-
-    methodLogger.logEnd("getKey", paramsString, compositeKey.toString());
-    return compositeKey.toString();
-  }
-
-  @Override
-  public <Type extends SerializableEntity<Type>> void create(final Context ctx, final Type entity)
-      throws EntityExistsException {
-    final String paramsString = methodLogger.generateParamsString(ctx, entity);
-    methodLogger.logStart("create", paramsString);
-
-    assertNotExists(ctx, entity);
-
-    final String key = getKey(ctx, entity);
-    final byte[] buffer = entity.toBuffer();
-    logger.debug("Calling stub#putState with key={} and value={}", key, Arrays.toString(buffer));
-    ctx.getStub().putState(key, buffer);
-
-    methodLogger.logEnd("create", paramsString, "<void>");
-  }
-
-  @Override
-  public <Type extends SerializableEntity<Type>> void update(final Context ctx, final Type entity)
-      throws EntityNotFoundException {
-    final String paramsString = methodLogger.generateParamsString(ctx, entity);
-    methodLogger.logStart("update", paramsString);
-
-    assertExists(ctx, entity);
-
-    final String key = getKey(ctx, entity);
-    final byte[] buffer = entity.toBuffer();
-    logger.debug("Calling stub#putState with key={} and value={}", key, Arrays.toString(buffer));
-    ctx.getStub().putState(key, buffer);
-
-    methodLogger.logEnd("update", paramsString, "<void>");
-  }
-
-  @Override
-  public <Type extends SerializableEntity<Type>> void delete(final Context ctx, final Type entity)
-      throws EntityNotFoundException {
-    final String paramsString = methodLogger.generateParamsString(ctx, entity);
-    methodLogger.logStart("delete", paramsString);
-
-    assertExists(ctx, entity);
-
-    final String key = getKey(ctx, entity);
-    logger.debug("Calling stub#delState with key={}", key);
-    ctx.getStub().delState(key);
-
-    methodLogger.logEnd("delete", paramsString, "<void>");
-  }
-
-  @Override
-  public <Type extends SerializableEntity<Type>> Type read(final Context ctx, final Type target)
-      throws EntityNotFoundException {
-    final String paramsString = methodLogger.generateParamsString(ctx, target);
-    methodLogger.logStart("read", paramsString);
-
-    final String key = getKey(ctx, target);
-    logger.debug("Calling stub#getState with key={}", key);
-    final byte[] data = ctx.getStub().getState(key);
-    logger.debug("Got data from stub#getState for key={}: {}", key, Arrays.toString(data));
-
-    if (data == null || data.length == 0) throw new EntityNotFoundException(key);
-
-    target.fromBuffer(data);
-    logger.debug("Deserialized entity from data; JSON representation={}", target.toJson());
-
-    methodLogger.logEnd("read", paramsString, target.toJson());
-    return target;
-  }
-
-  @Override
-  public <Type extends SerializableEntity<Type>> List<Type> readAll(
-      final Context ctx, final Type template) {
-    final String paramsString = methodLogger.generateParamsString(ctx, template);
-    methodLogger.logStart("readAll", paramsString);
-
-    final List<Type> entities = new ArrayList<>();
-    final String compositeKey = ctx.getStub().createCompositeKey(template.getType()).toString();
-    logger.debug("Calling stub#getStateByPartialCompositeKey with partial key={}", compositeKey);
-    for (KeyValue keyValue : ctx.getStub().getStateByPartialCompositeKey(compositeKey)) {
-      final byte[] value = keyValue.getValue();
-      logger.debug("Found value at partial key={}: {}", compositeKey, Arrays.toString(value));
-      final EntityFactory<Type> factory = template.getFactory();
-      final Type entity = factory.create();
-      entity.fromBuffer(value);
-      logger.debug("Deserialized entity from data; JSON representation={}", entity.toJson());
-      entities.add(entity);
-    }
-    logger.debug("Found {} entities in total for partial key={}", entities.size(), compositeKey);
-
-    methodLogger.logEnd("readAll", paramsString, entities.toString());
-    return entities;
-  }
-
-  @Override
-  public <Type extends SerializableEntity<Type>> SelectionBuilder<Type> select(
-      final Context ctx, final Type template) {
-    final String paramsString = methodLogger.generateParamsString(ctx, template);
-    methodLogger.logStart("select", paramsString);
-
-    final SelectionBuilder<Type> builder = new SelectionBuilderImpl<>(this.readAll(ctx, template));
-    methodLogger.logEnd("select", paramsString, builder.toString());
-    return builder;
-  }
-
-  private boolean keyExists(final Context ctx, final String key) {
-    final byte[] valueOnLedger = ctx.getStub().getState(key);
-    return valueOnLedger != null && valueOnLedger.length > 0;
-  }
-
-  public <Type extends SerializableEntity<Type>> boolean exists(final Context ctx, final Type obj) {
-    return keyExists(ctx, getKey(ctx, obj));
-  }
-
-  public <Type extends SerializableEntity<Type>> void assertNotExists(
-      final Context ctx, final Type obj) throws EntityExistsException {
-    if (exists(ctx, obj)) throw new EntityExistsException(getKey(ctx, obj));
-  }
-
-  public <Type extends SerializableEntity<Type>> void assertExists(
-      final Context ctx, final Type obj) throws EntityNotFoundException {
-    if (!exists(ctx, obj)) throw new EntityNotFoundException(getKey(ctx, obj));
-  }
-
-  private static final class SelectionBuilderImpl<Type extends SerializableEntity<Type>>
-      implements SelectionBuilder<Type> {
-
-    private List<Type> selection;
-
-    SelectionBuilderImpl(final List<Type> entities) {
-      this.selection = entities;
-    }
-
-    @Override
-    public SelectionBuilder<Type> matching(final Matcher<Type> matcher) {
-      final List<Type> newSelection = new ArrayList<>();
-      for (Type entity : this.selection) {
-        logger.debug("Testing matcher on entity (JSON): {}", entity.toJson());
-        if (matcher.match(entity)) {
-          logger.debug("Entity matches");
-          newSelection.add(entity);
-        } else logger.debug("Entity does not match");
-      }
-      logger.debug("Matched {} entities in total with matcher", newSelection.size());
-      this.selection = newSelection;
-      return this;
-    }
-
-    @Override
-    public SelectionBuilder<Type> sortedBy(final Comparator<Type> comparator) {
-      this.selection.sort(comparator);
-      logger.debug("Sorted entities");
-      return this;
-    }
-
-    @Override
-    public SelectionBuilder<Type> descending() {
-      Collections.reverse(this.selection);
-      logger.debug("Reversed entity order");
-      return this;
-    }
-
-    @Override
-    public List<Type> get() {
-      return this.selection;
-    }
-
-    @Override
-    public Type getFirst() {
-      if (this.selection.isEmpty()) {
-        logger.debug("No entites in this selection; returning null");
-        return null;
-      }
-
-      final Type first = this.selection.get(0);
-      logger.debug("Returning the first entity in selection (JSON): {}", first.toJson());
-      return first;
-    }
-  }
-}
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/SerializableEntity.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/SerializableEntity.java
deleted file mode 100644
index ba90160..0000000
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/SerializableEntity.java
+++ /dev/null
@@ -1,85 +0,0 @@
-/* SPDX-License-Identifier: Apache-2.0 */
-
-package hu.bme.mit.ftsrg.chaincode.dataaccess;
-
-/**
- * A generic database entity that can be serialized to JSON and to byte arrays.
- *
- * @param <Type> the type of the entity (required because of {@link
- *     SerializableEntity#getFactory()})
- * @see SerializableEntityBase
- */
-public interface SerializableEntity<Type extends SerializableEntity<Type>> {
-
-  /**
-   * Get the type of this entity; essentially a table name.
-   *
-   * <p>Usually this is an all-caps string, such as <code>CUSTOMER</code>.
-   *
-   * @return the arbitrary identifier of this entity type
-   * @see SerializableEntityBase#getType()
-   */
-  String getType();
-
-  /**
-   * Get the composite key for this entity.
-   *
-   * <p>The composite key is an array of strings comprising the primary key fields of the entity (ie
-   * those annotated with {@link KeyPart}).
-   *
-   * @return the composite key of this entity
-   * @see SerializableEntityBase#getKeyParts()
-   */
-  String[] getKeyParts();
-
-  /**
-   * Serialize this entity into a byte array.
-   *
-   * <p>The implementation is up to the developer, but it is recommended to simply return the
-   * encoded version of {@link SerializableEntity#toJson()}.
-   *
-   * @return this entity serialized into a byte array
-   * @see SerializableEntity#fromBuffer(byte[])
-   * @see SerializableEntityBase#toBuffer()
-   */
-  byte[] toBuffer();
-
-  /**
-   * Deserialize this entity from a byte array.
-   *
-   * <p>Naturally, this should do the inverse of {@link SerializableEntity#toBuffer()}
-   *
-   * @param buffer the buffer to parse
-   * @see SerializableEntity#toBuffer()
-   * @see SerializableEntityBase#fromBuffer(byte[])
-   */
-  void fromBuffer(byte[] buffer);
-
-  /**
-   * Serialize this entity into a JSON string.
-   *
-   * @return this entity serialized into a JSON string
-   * @see SerializableEntity#fromJson(String)
-   * @see SerializableEntityBase#toJson()
-   */
-  String toJson();
-
-  /**
-   * Deserialize this entity from a JSON string.
-   *
-   * <p>Naturally, this should do the inverse of {@link SerializableEntity#toJson()}
-   *
-   * @param json the JSON string to parse
-   * @see SerializableEntity#toJson()
-   * @see SerializableEntityBase#fromJson(String)
-   */
-  void fromJson(String json);
-
-  /**
-   * Get a factory for this entity type.
-   *
-   * @return A factory that can be used to create empty instances of this entity
-   * @see SerializableEntityBase#getFactory()
-   */
-  EntityFactory<Type> getFactory();
-}
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/SerializableEntityBase.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/SerializableEntityBase.java
deleted file mode 100644
index 905e781..0000000
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/SerializableEntityBase.java
+++ /dev/null
@@ -1,197 +0,0 @@
-/* SPDX-License-Identifier: Apache-2.0 */
-
-package hu.bme.mit.ftsrg.chaincode.dataaccess;
-
-import hu.bme.mit.ftsrg.chaincode.tpcc.util.JSON;
-import java.lang.reflect.Field;
-import java.lang.reflect.InvocationTargetException;
-import java.nio.charset.StandardCharsets;
-import java.util.*;
-import lombok.EqualsAndHashCode;
-import org.hyperledger.fabric.contract.annotation.DataType;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-/**
- * Base class for {@link SerializableEntity} entities.
- *
- * <p>This class provides some reflection-based implementations of the {@link SerializableEntity}
- * methods, so that you do not have to implement all the boilerplate yourself in the final entity
- * classes.
- *
- * @param <Type> the type of the entity
- */
-@EqualsAndHashCode
-@DataType
-public abstract class SerializableEntityBase<Type extends SerializableEntity<Type>>
-    implements SerializableEntity<Type> {
-
-  private static final Logger logger = LoggerFactory.getLogger(SerializableEntityBase.class);
-
-  /**
-   * Returns the entity type name, which is its class's name in all-uppercase.
-   *
-   * @return The name of the class of this entity, in all-uppercase
-   * @see SerializableEntity#getType()
-   */
-  @Override
-  public String getType() {
-    final String type = this.getClass().getName().toUpperCase();
-    logger.debug("Returning type name: {}", type);
-    return type;
-  }
-
-  /**
-   * Serializes this entity to a JSON and then to a byte array.
-   *
-   * @return This entity, serialized into a JSON string and then converted to a UTF-8 byte array.
-   * @see SerializableEntity#toBuffer()
-   */
-  @Override
-  public byte[] toBuffer() {
-    final String json = this.toJson();
-    final byte[] buffer = json.getBytes(StandardCharsets.UTF_8);
-    logger.debug("Returning buffer (size={}) from JSON: {}", buffer.length, json);
-    return buffer;
-  }
-
-  /**
-   * Deserializes this entity from a byte array.
-   *
-   * @param buffer the buffer to parse
-   * @see SerializableEntityBase#toBuffer()
-   */
-  @Override
-  public void fromBuffer(final byte[] buffer) {
-    final String json = new String(buffer, StandardCharsets.UTF_8);
-    logger.debug("Parsing entity from JSON: {}", json);
-    this.fromJson(json);
-  }
-
-  /**
-   * Serializes this entity into a JSON.
-   *
-   * @return this entity as a JSON string
-   * @see SerializableEntity#toJson()
-   */
-  @Override
-  public String toJson() {
-    final String json = JSON.serialize(this);
-    logger.debug("Returning JSON string from entity: {}", json);
-    return json;
-  }
-
-  /**
-   * Deserializes this entity from a JSON.
-   *
-   * <p>This reflection-based implementation sets all fields with matching names from the JSON.
-   * Fields that are not found in the JSON remain unset. Conversely, extraneous keys in the JSON are
-   * ignored.
-   *
-   * @param json the JSON string to parse
-   * @see SerializableEntityBase#toJson()
-   */
-  @Override
-  public void fromJson(final String json) {
-    logger.debug("Deserializing from JSON string: {}...", json);
-    final Object obj = JSON.deserialize(json, this.getClass());
-    final Field[] ourFields = this.getClass().getDeclaredFields();
-    /*
-     * Try to get values for our known fields from the deserialized
-     * object.  This process is forgiving: if one of our fields does not
-     * exist inside the deserialized object, we leave it as is; if the
-     * deserialized object contains fields we do not recognize, we
-     * silently ignore them.
-     */
-    for (final Field ourField : ourFields) {
-      logger.debug("Attempting to set field {}", ourField.getName());
-      ourField.setAccessible(true);
-      try {
-        final Field theirField = obj.getClass().getDeclaredField(ourField.getName());
-        theirField.setAccessible(true);
-        try {
-          ourField.set(this, theirField.get(obj));
-        } catch (IllegalArgumentException | IllegalAccessException e) {
-          logger.error("Got exception while trying to access/set a field", e);
-          e.printStackTrace();
-        }
-      } catch (NoSuchFieldException e) {
-        logger.error("Got exception while trying to access/set a field", e);
-        e.printStackTrace();
-      }
-    }
-  }
-
-  /**
-   * Get the composite key for this entity.
-   *
-   * <p>This reference implementation takes all fields annotated with {@link KeyPart} in the entity
-   * class, pads them to {@link SerializableEntityBase#padLength} and creates an array from those.
-   *
-   * <p><b>WARNING:</b> the order of keys might matter; this implementation has not been tested.
-   *
-   * @return the composite key of this entity
-   */
-  @Override
-  public String[] getKeyParts() {
-    // Stream-based implementation replaced with code below to accommodate OpenJML...
-    final List<String> keyParts = new ArrayList<>();
-    for (final Field field : this.getClass().getDeclaredFields()) {
-      logger.debug("Checking if field {} is a key part...", field.getName());
-      field.setAccessible(true);
-      if (field.isAnnotationPresent(KeyPart.class)) {
-        logger.debug("Field {} seems to be a key part; getting its value", field.getName());
-        try {
-          keyParts.add(pad(field.getInt(this)));
-        } catch (IllegalAccessException e) {
-          logger.error("Failed to get the value of a key part", e);
-          throw new RuntimeException(e);
-        }
-      }
-    }
-
-    logger.debug("Returning key parts for entity: {}", keyParts);
-    return keyParts.toArray(new String[0]);
-  }
-
-  /**
-   * Get a factory that can instantiate this entity.
-   *
-   * <p><b>WARNING:</b> this is a rather lousy reflection-based implementation that has not been
-   * tested
-   *
-   * @return a {@link EntityFactory} for this entity type
-   */
-  @Override
-  public EntityFactory<Type> getFactory() {
-    final Class<? extends SerializableEntityBase> ourClass = this.getClass();
-    // Lambda-based implementation replaced with code below to accommodate OpenJML...
-    return new EntityFactory<>() {
-      @Override
-      public Type create() {
-        logger.debug("Was asked to create a new entity instance of {}...", ourClass.getName());
-        try {
-          return (Type) ourClass.getDeclaredConstructor().newInstance();
-        } catch (InstantiationException
-            | IllegalAccessException
-            | InvocationTargetException
-            | NoSuchMethodException e) {
-          logger.error("Failed to create new entity instance using factory", e);
-          throw new RuntimeException(e);
-        }
-      }
-    };
-  }
-
-  private static final int padLength = Integer.toString(Integer.MAX_VALUE).length();
-
-  /**
-   * Converts the number to text and pads it to a fix length.
-   *
-   * @param num The number to pad.
-   * @return The padded number text.
-   */
-  private static String pad(final int num) {
-    return String.format("%0" + padLength + "d", num);
-  }
-}
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/exception/DataAccessException.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/exception/DataAccessException.java
deleted file mode 100644
index 7623311..0000000
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/exception/DataAccessException.java
+++ /dev/null
@@ -1,12 +0,0 @@
-package hu.bme.mit.ftsrg.chaincode.dataaccess.exception;
-
-public abstract class DataAccessException extends Exception {
-
-  public DataAccessException(final String message) {
-    super(message);
-  }
-
-  public DataAccessException(final String message, final Throwable cause) {
-    super(message, cause);
-  }
-}
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/exception/EntityExistsException.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/exception/EntityExistsException.java
deleted file mode 100644
index 8670f5f..0000000
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/exception/EntityExistsException.java
+++ /dev/null
@@ -1,8 +0,0 @@
-package hu.bme.mit.ftsrg.chaincode.dataaccess.exception;
-
-public class EntityExistsException extends DataAccessException {
-
-  public EntityExistsException(final String key) {
-    super("Entity with key '%s' already exists".formatted(key));
-  }
-}
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/exception/EntityNotFoundException.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/exception/EntityNotFoundException.java
deleted file mode 100644
index f80cdf2..0000000
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/dataaccess/exception/EntityNotFoundException.java
+++ /dev/null
@@ -1,8 +0,0 @@
-package hu.bme.mit.ftsrg.chaincode.dataaccess.exception;
-
-public class EntityNotFoundException extends DataAccessException {
-
-  public EntityNotFoundException(final String key) {
-    super("Entity with key '%s' could not be found".formatted(key));
-  }
-}
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/api/NotFoundException.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/api/NotFoundException.java
index b6be956..7afab25 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/api/NotFoundException.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/api/NotFoundException.java
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 */
 package hu.bme.mit.ftsrg.chaincode.tpcc.api;
 
 public final class NotFoundException extends Exception {
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/api/TPCCBusinessAPI.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/api/TPCCBusinessAPI.java
index c1c1bc7..83b14dc 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/api/TPCCBusinessAPI.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/api/TPCCBusinessAPI.java
@@ -1,19 +1,19 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.api;
 
 import com.jcabi.aspects.Loggable;
 import hu.bme.mit.ftsrg.chaincode.MethodLogger;
-import hu.bme.mit.ftsrg.chaincode.dataaccess.ContextWithRegistry;
-import hu.bme.mit.ftsrg.chaincode.dataaccess.Registry;
-import hu.bme.mit.ftsrg.chaincode.dataaccess.exception.EntityExistsException;
-import hu.bme.mit.ftsrg.chaincode.dataaccess.exception.EntityNotFoundException;
 import hu.bme.mit.ftsrg.chaincode.tpcc.data.entity.*;
 import hu.bme.mit.ftsrg.chaincode.tpcc.data.extra.*;
 import hu.bme.mit.ftsrg.chaincode.tpcc.data.input.*;
 import hu.bme.mit.ftsrg.chaincode.tpcc.data.output.*;
 import hu.bme.mit.ftsrg.chaincode.tpcc.middleware.TPCCContext;
 import hu.bme.mit.ftsrg.chaincode.tpcc.util.JSON;
+import hu.bme.mit.ftsrg.hypernate.Registry;
+import hu.bme.mit.ftsrg.hypernate.context.ContextWithRegistry;
+import hu.bme.mit.ftsrg.hypernate.entity.EntityExistsException;
+import hu.bme.mit.ftsrg.hypernate.entity.EntityNotFoundException;
+import hu.bme.mit.ftsrg.hypernate.entity.SerializationException;
 import java.util.*;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -39,7 +39,7 @@ class TPCCBusinessAPI {
    * @return The transaction output
    */
   static DeliveryOutput delivery(final TPCCContext ctx, final DeliveryInput input)
-      throws EntityNotFoundException {
+      throws EntityNotFoundException, SerializationException {
 
     /*
      * [TPC-C 2.7.4.2]
@@ -101,7 +101,7 @@ static DeliveryOutput delivery(final TPCCContext ctx, final DeliveryInput input)
    * @return The transaction output
    */
   static NewOrderOutput newOrder(final TPCCContext ctx, final NewOrderInput input)
-      throws EntityNotFoundException, EntityExistsException {
+      throws EntityNotFoundException, EntityExistsException, SerializationException {
     /*
      * [TPC-C 2.4.2.2]
      * For a given warehouse number (W_ID), district number (D_W_ID,
@@ -119,7 +119,7 @@ static NewOrderOutput newOrder(final TPCCContext ctx, final NewOrderInput input)
      * and W_TAX, the warehouse tax rate, is retrieved.
      */
     final Warehouse warehouse = Warehouse.builder().id(input.getW_id()).build();
-    registry.read(ctx, warehouse);
+    registry.read(warehouse);
 
     /*
      * [TPC-C 2.4.2.2 (4)]
@@ -128,7 +128,7 @@ static NewOrderOutput newOrder(final TPCCContext ctx, final NewOrderInput input)
      */
     final District district =
         District.builder().w_id(warehouse.getW_id()).id(input.getD_id()).build();
-    registry.read(ctx, district);
+    registry.read(district);
     /*
      * [TPC-C 2.4.2.2 (4) (continued)]
      * ... and D_NEXT_O_ID, the next available order number for the
@@ -136,7 +136,7 @@ static NewOrderOutput newOrder(final TPCCContext ctx, final NewOrderInput input)
      */
     final int nextOrderId = district.getD_next_o_id();
     district.incrementNextOrderID();
-    registry.update(ctx, district);
+    registry.update(district);
     logger.debug(
         "Next available order number for DISTRICT with D_ID={} incremented; new DISTRICT: {}",
         district.getD_id(),
@@ -155,7 +155,7 @@ static NewOrderOutput newOrder(final TPCCContext ctx, final NewOrderInput input)
             .d_id(district.getD_id())
             .id(input.getC_id())
             .build();
-    registry.read(ctx, customer);
+    registry.read(customer);
 
     /*
      * [TPC-C 2.4.2.2 (6)]
@@ -168,7 +168,7 @@ static NewOrderOutput newOrder(final TPCCContext ctx, final NewOrderInput input)
             .d_id(district.getD_id())
             .w_id(warehouse.getW_id())
             .build();
-    registry.create(ctx, newOrder);
+    registry.create(newOrder);
     /*
      * [TPC-C 2.4.2.2 (6) (continued)]
      * ... O_CARRIER_ID is set to a null value.  If the order includes
@@ -190,7 +190,7 @@ static NewOrderOutput newOrder(final TPCCContext ctx, final NewOrderInput input)
             .ol_cnt(input.getI_ids().length)
             .all_local(allMatch(input.getI_w_ids(), warehouse.getW_id()) ? 1 : 0)
             .build();
-    registry.create(ctx, order);
+    registry.create(order);
 
     /*
      * [TPC-C 2.4.2.2 (8)]
@@ -213,7 +213,7 @@ static NewOrderOutput newOrder(final TPCCContext ctx, final NewOrderInput input)
        */
       final Item item = Item.builder().id(i_ids[i]).build();
       try {
-        registry.read(ctx, item);
+        registry.read(item);
       } catch (EntityNotFoundException e) {
         /*
          * [TPC-C 2.4.2.3]
@@ -304,7 +304,7 @@ static NewOrderOutput newOrder(final TPCCContext ctx, final NewOrderInput input)
    * @return The transaction output
    */
   static OrderStatusOutput orderStatus(final TPCCContext ctx, final OrderStatusInput input)
-      throws NotFoundException, EntityNotFoundException {
+      throws NotFoundException, EntityNotFoundException, SerializationException {
     /*
      * [TPC-C 2.6.2.2]
      * For a given customer number (C_W_ID, C_D_ID, C_ID): ...
@@ -392,7 +392,10 @@ static OrderStatusOutput orderStatus(final TPCCContext ctx, final OrderStatusInp
    * @return The JSON encoded query results according to the specification.
    */
   static PaymentOutput payment(final TPCCContext ctx, final PaymentInput input)
-      throws EntityNotFoundException, EntityExistsException, NotFoundException {
+      throws EntityNotFoundException,
+          EntityExistsException,
+          NotFoundException,
+          SerializationException {
     /*
      * [TPC-C 2.5.2.2]
      * For a given warehouse number (W_ID), district number (D_W_ID,
@@ -410,14 +413,14 @@ static PaymentOutput payment(final TPCCContext ctx, final PaymentInput input)
      * retrieved [...]
      */
     final Warehouse warehouse = Warehouse.builder().id(input.getW_id()).build();
-    registry.read(ctx, warehouse);
+    registry.read(warehouse);
     /*
      * [TPC-C 2.5.2.2 (3) (continued)]
      * ... and W_YTD, the warehouse's year-to-date balance, is
      * increased by H_AMOUNT.
      */
     warehouse.increaseYTD(input.getH_amount());
-    registry.update(ctx, warehouse);
+    registry.update(warehouse);
 
     /*
      * [TPC-C 2.5.2.2 (4)]
@@ -427,14 +430,14 @@ static PaymentOutput payment(final TPCCContext ctx, final PaymentInput input)
      */
     final District district =
         District.builder().w_id(warehouse.getW_id()).id(input.getD_id()).build();
-    registry.read(ctx, district);
+    registry.read(district);
     /*
      * [TPC-C 2.5.2.2 (4) (continued)]
      * ... and D_YTD, the district's year-to-date balance, is
      * increased by H_AMOUNT.
      */
     district.increaseYTD(input.getH_amount());
-    registry.update(ctx, district);
+    registry.update(district);
 
     /*
      * [TPC-C 2.5.2.2 (5.1)]
@@ -506,7 +509,7 @@ static PaymentOutput payment(final TPCCContext ctx, final PaymentInput input)
      * [TPC-C 2.5.2.2 (6) (continued)]
      * ... The selected customer is updated with the new C_DATA field.
      */
-    registry.update(ctx, customer);
+    registry.update(customer);
 
     /*
      * [TPC-C 2.5.2.2 (7)]
@@ -531,7 +534,7 @@ static PaymentOutput payment(final TPCCContext ctx, final PaymentInput input)
             .amount(input.getH_amount())
             .data(h_data)
             .build();
-    registry.create(ctx, history);
+    registry.create(history);
 
     /*
      * [TPC-C 2.5.3.3]
@@ -568,7 +571,7 @@ static PaymentOutput payment(final TPCCContext ctx, final PaymentInput input)
    * @return The transaction output
    */
   static StockLevelOutput stockLevel(final TPCCContext ctx, final StockLevelInput input)
-      throws EntityNotFoundException, NotFoundException {
+      throws EntityNotFoundException, NotFoundException, SerializationException {
     /*
      * [TPC-C 2.8.2.2]
      * For a given warehouse number (W_ID), district number (D_W_ID,
@@ -581,7 +584,7 @@ static StockLevelOutput stockLevel(final TPCCContext ctx, final StockLevelInput
      * selected and D_NEXT_O_ID is retrieved.
      */
     final District district = District.builder().w_id(input.getW_id()).id(input.getD_id()).build();
-    ctx.getRegistry().read(ctx, district);
+    ctx.getRegistry().read(district);
 
     /*
      * [TPC-C 2.8.2.2 (4)]
@@ -608,7 +611,7 @@ static StockLevelOutput stockLevel(final TPCCContext ctx, final StockLevelInput
     int lowStock = 0;
     for (final int i_id : recentItemIds) {
       final Stock stock = Stock.builder().w_id(input.getW_id()).i_id(i_id).build();
-      ctx.getRegistry().read(ctx, stock);
+      ctx.getRegistry().read(stock);
       if (stock.getS_quantity() < input.getThreshold()) {
         logger.debug("The stock quantity is less than the threshold");
         ++lowStock;
@@ -635,7 +638,7 @@ static StockLevelOutput stockLevel(final TPCCContext ctx, final StockLevelInput
    *
    * @param ctx The transaction context
    */
-  static void init(final TPCCContext ctx) throws EntityExistsException {
+  static void init(final TPCCContext ctx) throws EntityExistsException, SerializationException {
     initWarehouses(ctx);
     initDistricts(ctx);
     initCustomers(ctx);
@@ -686,7 +689,8 @@ private static String padDistrictInfo(final String info) {
    * @param ctx The transaction context
    * @throws EntityExistsException if a warehouse entry already exists on the ledger
    */
-  private static void initWarehouses(final ContextWithRegistry ctx) throws EntityExistsException {
+  private static void initWarehouses(final ContextWithRegistry ctx)
+      throws EntityExistsException, SerializationException {
     final String paramString = methodLogger.generateParamsString(ctx.toString());
     methodLogger.logStart("initWarehouses", paramString);
 
@@ -703,7 +707,7 @@ private static void initWarehouses(final ContextWithRegistry ctx) throws EntityE
             .ytd(10000)
             .build();
 
-    ctx.getRegistry().create(ctx, warehouse);
+    ctx.getRegistry().create(warehouse);
 
     methodLogger.logEnd("initWarehouses", paramString, "<void>");
   }
@@ -717,7 +721,8 @@ private static void initWarehouses(final ContextWithRegistry ctx) throws EntityE
    * @param ctx The transaction context
    * @throws EntityExistsException if a district entry already exists on the ledger
    */
-  private static void initDistricts(final ContextWithRegistry ctx) throws EntityExistsException {
+  private static void initDistricts(final ContextWithRegistry ctx)
+      throws EntityExistsException, SerializationException {
     final String paramString = methodLogger.generateParamsString(ctx.toString());
     methodLogger.logStart("initDistricts", paramString);
 
@@ -736,7 +741,7 @@ private static void initDistricts(final ContextWithRegistry ctx) throws EntityEx
             .next_o_id(3001)
             .build();
 
-    ctx.getRegistry().create(ctx, district);
+    ctx.getRegistry().create(district);
 
     methodLogger.logEnd("initDistricts", paramString, "<void>");
   }
@@ -750,7 +755,8 @@ private static void initDistricts(final ContextWithRegistry ctx) throws EntityEx
    * @param ctx The transaction context
    * @throws EntityExistsException if a customer entry already exists on the ledger
    */
-  private static void initCustomers(final ContextWithRegistry ctx) throws EntityExistsException {
+  private static void initCustomers(final ContextWithRegistry ctx)
+      throws EntityExistsException, SerializationException {
     final String paramString = methodLogger.generateParamsString(ctx.toString());
     methodLogger.logStart("initCustomers", paramString);
 
@@ -804,8 +810,8 @@ private static void initCustomers(final ContextWithRegistry ctx) throws EntityEx
             .build();
 
     final Registry registry = ctx.getRegistry();
-    registry.create(ctx, alice);
-    registry.create(ctx, peter);
+    registry.create(alice);
+    registry.create(peter);
 
     methodLogger.logEnd("initDistricts", paramString, "<void>");
   }
@@ -819,7 +825,8 @@ private static void initCustomers(final ContextWithRegistry ctx) throws EntityEx
    * @param ctx The transaction context
    * @throws EntityExistsException if an item entry already exists on the ledger
    */
-  private static void initItems(final ContextWithRegistry ctx) throws EntityExistsException {
+  private static void initItems(final ContextWithRegistry ctx)
+      throws EntityExistsException, SerializationException {
     final String paramString = methodLogger.generateParamsString(ctx.toString());
     methodLogger.logStart("initItems", paramString);
 
@@ -831,9 +838,9 @@ private static void initItems(final ContextWithRegistry ctx) throws EntityExists
         Item.builder().id(3).im_id(456).name("Glass").price(78.00).data("GENERIC").build();
 
     final Registry registry = ctx.getRegistry();
-    registry.create(ctx, cup);
-    registry.create(ctx, plate);
-    registry.create(ctx, glass);
+    registry.create(cup);
+    registry.create(plate);
+    registry.create(glass);
 
     methodLogger.logEnd("initItems", paramString, "<void>");
   }
@@ -847,7 +854,8 @@ private static void initItems(final ContextWithRegistry ctx) throws EntityExists
    * @param ctx The transaction context
    * @throws EntityExistsException if a stock entry already exists on the ledger
    */
-  private static void initStocks(final ContextWithRegistry ctx) throws EntityExistsException {
+  private static void initStocks(final ContextWithRegistry ctx)
+      throws EntityExistsException, SerializationException {
     final String paramString = methodLogger.generateParamsString(ctx.toString());
     methodLogger.logStart("initStocks", paramString);
 
@@ -889,9 +897,9 @@ private static void initStocks(final ContextWithRegistry ctx) throws EntityExist
             .build();
 
     final Registry registry = ctx.getRegistry();
-    registry.create(ctx, stock1);
-    registry.create(ctx, stock2);
-    registry.create(ctx, stock3);
+    registry.create(stock1);
+    registry.create(stock2);
+    registry.create(stock3);
 
     methodLogger.logEnd("initStocks", paramString, "<void>");
   }
@@ -937,13 +945,13 @@ private static String generateHistoryInformation(
    */
   private static OrderLineData getOrderLineDataForOrder(
       final ContextWithRegistry ctx, final Order order, final int number)
-      throws EntityNotFoundException {
+      throws EntityNotFoundException, SerializationException {
     final String paramString =
         methodLogger.generateParamsString(ctx.toString(), order.toString(), String.valueOf(number));
     methodLogger.logStart("getOrderLineDataForOrder", paramString);
 
     final OrderLine orderLine = OrderLine.builder().fromOrder(order).number(number).build();
-    ctx.getRegistry().read(ctx, orderLine);
+    ctx.getRegistry().read(orderLine);
 
     final OrderLineData orderLineData = OrderLineData.builder().fromOrderLine(orderLine).build();
 
@@ -970,7 +978,7 @@ private static DeliveredOrder deliverOldestNewOrderForDistrict(
       final int d_id,
       final int o_carrier_id,
       final String ol_delivery_d)
-      throws EntityNotFoundException {
+      throws EntityNotFoundException, SerializationException {
     final String paramString =
         methodLogger.generateParamsString(
             methodLogger.generateParamsString(ctx, w_id, d_id, o_carrier_id), ol_delivery_d);
@@ -987,7 +995,7 @@ private static DeliveredOrder deliverOldestNewOrderForDistrict(
      */
     final List<NewOrder> matchingNewOrders =
         registry
-            .select(ctx, new NewOrder())
+            .select(new NewOrder())
             /* TODO this code causes a StackOverflowError for some reason
             .matching(
                 new Registry.Matcher<NewOrder>() {
@@ -1037,7 +1045,7 @@ public int compare(final NewOrder a, final NewOrder b) {
      * [TPC-C 2.7.4.2 (4)]
      * The selected row in the NEW-ORDER table is deleted.
      */
-    registry.delete(ctx, oldestNewOrder);
+    registry.delete(oldestNewOrder);
 
     /*
      * [TPC-C 2.7.4.2 (5)]
@@ -1047,13 +1055,13 @@ public int compare(final NewOrder a, final NewOrder b) {
      */
     final Order order =
         Order.builder().w_id(w_id).d_id(d_id).id(oldestNewOrder.getNo_o_id()).build();
-    registry.read(ctx, order);
+    registry.read(order);
     /*
      * [TPC-C 2.7.4.2 (5) (continued)]
      * ... and O_CARRIER_ID is updated.
      */
     order.setO_carrier_id(o_carrier_id);
-    registry.update(ctx, order);
+    registry.update(order);
 
     /*
      * [TPC-C 2.7.4.2 (6)]
@@ -1075,7 +1083,7 @@ public int compare(final NewOrder a, final NewOrder b) {
      */
     final Customer customer =
         Customer.builder().w_id(w_id).d_id(d_id).id(order.getO_c_id()).build();
-    registry.read(ctx, customer);
+    registry.read(customer);
     /*
      * [TPC-C 2.7.4.2 (7) (continued)]
      * ... and C_BALANCE is increased by the sum of all order-line
@@ -1087,7 +1095,7 @@ public int compare(final NewOrder a, final NewOrder b) {
      * ... C_DELIVERY_CNT is incremented by 1.
      */
     customer.incrementDeliveryCount();
-    registry.update(ctx, customer);
+    registry.update(customer);
 
     final DeliveredOrder deliveredOrder =
         DeliveredOrder.builder().d_id(d_id).o_id(order.getO_id()).build();
@@ -1105,7 +1113,7 @@ public int compare(final NewOrder a, final NewOrder b) {
    *
    * <p><b>NOTE:</b> this code has been factored out of {@link TPCCContractAPI#delivery(TPCCContext,
    * String)} (and then consequently from {@link
-   * TPCCContractAPI#deliverOldestNewOrderForDistrict(ContextWithRegistry, int, int, int, String)})
+   * TPCCBusinessAPI#deliverOldestNewOrderForDistrict(ContextWithRegistry, int, int, int, String)})
    * only so that OpenJML won't choke on the exceedingly long method.
    *
    * @param ctx The transaction context
@@ -1123,7 +1131,7 @@ private static double getOrderLineAmountAndUpdateTime(
       final int o_id,
       final int number,
       final String ol_delivery_d)
-      throws EntityNotFoundException {
+      throws EntityNotFoundException, SerializationException {
     final String paramString =
         methodLogger.generateParamsString(
             methodLogger.generateParamsString(ctx, w_id, d_id, o_id, number), ol_delivery_d);
@@ -1137,7 +1145,7 @@ private static double getOrderLineAmountAndUpdateTime(
      */
     final OrderLine orderLine =
         OrderLine.builder().w_id(w_id).d_id(d_id).o_id(o_id).number(number).build();
-    ctx.getRegistry().read(ctx, orderLine);
+    ctx.getRegistry().read(orderLine);
     /*
      * [TPC-C 2.7.4.2 (6) (continued)]
      * ... All OL_DELIVERY_D, the delivery dates, are updated to the
@@ -1148,7 +1156,7 @@ private static double getOrderLineAmountAndUpdateTime(
      * [TPC-C 2.7.4.2 (6) (continued)]
      * ... and the sum of all OL_AMOUNT is retrieved.
      */
-    ctx.getRegistry().update(ctx, orderLine);
+    ctx.getRegistry().update(orderLine);
 
     methodLogger.logEnd(
         "getOrderLineAmountAndUpdateTime", paramString, String.valueOf(orderLine.getOl_amount()));
@@ -1200,7 +1208,7 @@ private static double createOrderLineAndGetAmount(
       final int nextOrderId,
       final int number,
       final Collection<ItemsData> itemsDataCollection)
-      throws EntityNotFoundException, EntityExistsException {
+      throws EntityNotFoundException, EntityExistsException, SerializationException {
     final String paramString =
         methodLogger.generateParamsString(
             methodLogger.generateParamsString(
@@ -1219,7 +1227,7 @@ private static double createOrderLineAndGetAmount(
      * [...]
      */
     final Stock stock = Stock.builder().w_id(i_w_id).i_id(i_id).build();
-    registry.read(ctx, stock);
+    registry.read(stock);
     /*
      * [TPC-C 2.4.2.2 (8.2) (continued)]
      * ... If the retrieved value for S_QUANTITY exceeds OL_QUANTITY
@@ -1250,7 +1258,7 @@ private static double createOrderLineAndGetAmount(
     if (i_w_id != w_id) {
       stock.incrementRemoteCount();
     }
-    registry.update(ctx, stock);
+    registry.update(stock);
 
     /*
      * [TPC-C 2.4.2.2 (8.3)]
@@ -1291,7 +1299,7 @@ private static double createOrderLineAndGetAmount(
             .amount(orderLineAmount)
             .dist_info(padDistrictInfo(stock.getS_dist(d_id)))
             .build();
-    registry.create(ctx, orderLine);
+    registry.create(orderLine);
 
     /*
      * [TPC-C 2.4.3.3]
@@ -1347,7 +1355,7 @@ private static Customer getCustomerByIDOrLastName(
       final int c_d_id,
       final Integer c_id,
       final String c_last)
-      throws EntityNotFoundException, NotFoundException {
+      throws EntityNotFoundException, NotFoundException, SerializationException {
     final String paramString =
         methodLogger.generateParamsString(
             methodLogger.generateParamsString(ctx, c_w_id, c_d_id, c_id), c_last);
@@ -1359,13 +1367,12 @@ private static Customer getCustomerByIDOrLastName(
 
     if (c_id != null) {
       final Customer customer =
-          ctx.getRegistry()
-              .read(ctx, Customer.builder().w_id(c_w_id).d_id(c_d_id).id(c_id).build());
+          ctx.getRegistry().read(Customer.builder().w_id(c_w_id).d_id(c_d_id).id(c_id).build());
       methodLogger.logEnd("getCustomerByIDOrLastName", paramString, JSON.serialize(customer));
       return customer;
     } else {
       final List<Customer> allCustomers =
-          ctx.getRegistry().readAll(ctx, Customer.builder().w_id(c_w_id).d_id(c_d_id).build());
+          ctx.getRegistry().readAll(Customer.builder().w_id(c_w_id).d_id(c_d_id).build());
 
       // Stream-based one-liner replaced with below code to accommodate OpenJML...
       final List<Customer> matchingCustomers = new ArrayList<>();
@@ -1410,13 +1417,13 @@ public int compare(final Customer a, final Customer b) {
    */
   private static Order getLastOrderOfCustomer(
       final ContextWithRegistry ctx, final int o_w_id, final int o_d_id, final int o_c_id)
-      throws NotFoundException {
+      throws NotFoundException, SerializationException {
     final String paramString = methodLogger.generateParamsString(ctx, o_w_id, o_d_id, o_c_id);
     methodLogger.logStart("getLastOrderOfCustomer", paramString);
 
     Registry registry = ctx.getRegistry();
     final List<Order> allOrders =
-        registry.readAll(ctx, Order.builder().w_id(o_w_id).d_id(o_d_id).build());
+        registry.readAll(Order.builder().w_id(o_w_id).d_id(o_d_id).build());
     if (allOrders.isEmpty()) {
       throw new NotFoundException("No orders found");
     }
@@ -1460,7 +1467,7 @@ private static List<Integer> getItemIdsOfRecentOrders(
       final int d_id,
       final int o_id_min,
       final int o_id_max)
-      throws EntityNotFoundException, NotFoundException {
+      throws EntityNotFoundException, NotFoundException, SerializationException {
     final String paramString =
         methodLogger.generateParamsString(ctx, w_id, d_id, o_id_min, o_id_max);
     methodLogger.logStart("getItemIdsOfRecentOrders", paramString);
@@ -1470,7 +1477,7 @@ private static List<Integer> getItemIdsOfRecentOrders(
       final Order order = Order.builder().w_id(w_id).d_id(d_id).id(current_o_id).build();
 
       try {
-        ctx.getRegistry().read(ctx, order);
+        ctx.getRegistry().read(order);
       } catch (EntityNotFoundException _e) {
         logger.warn(
             "Order with o_id={} not found while looking up recent orders; ignoring", current_o_id);
@@ -1480,7 +1487,7 @@ private static List<Integer> getItemIdsOfRecentOrders(
       for (int ol_number = 1; ol_number <= order.getO_ol_cnt(); ol_number++) {
         final OrderLine orderLine =
             OrderLine.builder().w_id(w_id).d_id(d_id).o_id(current_o_id).number(ol_number).build();
-        ctx.getRegistry().read(ctx, orderLine);
+        ctx.getRegistry().read(orderLine);
         itemIds.add(orderLine.getOl_i_id());
       }
     }
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/api/TPCCContractAPI.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/api/TPCCContractAPI.java
index e0b4c7a..3599e7c 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/api/TPCCContractAPI.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/api/TPCCContractAPI.java
@@ -1,15 +1,15 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.api;
 
 import com.jcabi.aspects.Loggable;
 import hu.bme.mit.ftsrg.chaincode.MethodLogger;
-import hu.bme.mit.ftsrg.chaincode.dataaccess.exception.EntityExistsException;
-import hu.bme.mit.ftsrg.chaincode.dataaccess.exception.EntityNotFoundException;
 import hu.bme.mit.ftsrg.chaincode.tpcc.data.entity.*;
 import hu.bme.mit.ftsrg.chaincode.tpcc.data.input.*;
 import hu.bme.mit.ftsrg.chaincode.tpcc.middleware.TPCCContext;
 import hu.bme.mit.ftsrg.chaincode.tpcc.util.JSON;
+import hu.bme.mit.ftsrg.hypernate.entity.EntityExistsException;
+import hu.bme.mit.ftsrg.hypernate.entity.EntityNotFoundException;
+import hu.bme.mit.ftsrg.hypernate.entity.SerializationException;
 import org.hyperledger.fabric.contract.Context;
 import org.hyperledger.fabric.contract.ContractInterface;
 import org.hyperledger.fabric.contract.annotation.Contact;
@@ -60,7 +60,7 @@ public Context createContext(final ChaincodeStub stub) {
    */
   @Transaction(intent = Transaction.TYPE.SUBMIT)
   public String delivery(final TPCCContext ctx, final String parameters)
-      throws EntityNotFoundException {
+      throws EntityNotFoundException, SerializationException {
     final String paramString = methodLogger.generateParamsString(ctx, parameters);
     methodLogger.logStart("delivery", paramString);
     final String json =
@@ -81,7 +81,7 @@ public String delivery(final TPCCContext ctx, final String parameters)
    */
   @Transaction(intent = Transaction.TYPE.SUBMIT)
   public String newOrder(final TPCCContext ctx, final String parameters)
-      throws EntityNotFoundException, EntityExistsException {
+      throws EntityNotFoundException, EntityExistsException, SerializationException {
     final String paramString = methodLogger.generateParamsString(ctx, parameters);
     methodLogger.logStart("newOrder", paramString);
     final String json =
@@ -100,7 +100,7 @@ public String newOrder(final TPCCContext ctx, final String parameters)
    */
   @Transaction(intent = Transaction.TYPE.EVALUATE)
   public String orderStatus(final TPCCContext ctx, final String parameters)
-      throws NotFoundException, EntityNotFoundException {
+      throws NotFoundException, EntityNotFoundException, SerializationException {
     final String paramString = methodLogger.generateParamsString(ctx, parameters);
     methodLogger.logStart("orderStatus", paramString);
     final String json =
@@ -122,7 +122,7 @@ public String orderStatus(final TPCCContext ctx, final String parameters)
    */
   @Transaction(intent = Transaction.TYPE.SUBMIT)
   public String payment(final TPCCContext ctx, final String parameters)
-      throws EntityNotFoundException, EntityExistsException, NotFoundException {
+      throws EntityNotFoundException, EntityExistsException, NotFoundException, SerializationException {
     final String paramString = methodLogger.generateParamsString(ctx, parameters);
     methodLogger.logStart("payment", paramString);
     final String json =
@@ -143,7 +143,7 @@ public String payment(final TPCCContext ctx, final String parameters)
    */
   @Transaction(intent = Transaction.TYPE.EVALUATE)
   public String stockLevel(final TPCCContext ctx, final String parameters)
-      throws EntityNotFoundException, NotFoundException {
+      throws EntityNotFoundException, NotFoundException, SerializationException {
     final String paramString = methodLogger.generateParamsString(ctx, parameters);
     methodLogger.logStart("stockLevel", paramString);
     final String json =
@@ -159,7 +159,7 @@ public String stockLevel(final TPCCContext ctx, final String parameters)
    * @param ctx The transaction context
    */
   @Transaction(intent = Transaction.TYPE.SUBMIT)
-  public void init(final TPCCContext ctx) throws EntityExistsException {
+  public void init(final TPCCContext ctx) throws EntityExistsException, SerializationException {
     final String paramString = methodLogger.generateParamsString(ctx.toString());
     methodLogger.logStart("init", paramString);
     TPCCBusinessAPI.init(ctx);
@@ -175,12 +175,12 @@ public void init(final TPCCContext ctx) throws EntityExistsException {
    */
   @Transaction(intent = Transaction.TYPE.EVALUATE)
   public String readWarehouse(final TPCCContext ctx, final int w_id)
-      throws EntityNotFoundException {
+      throws EntityNotFoundException, SerializationException {
     final String paramString = methodLogger.generateParamsString(ctx, w_id);
     methodLogger.logStart("readWarehouse", paramString);
 
     final Warehouse warehouse = Warehouse.builder().id(w_id).build();
-    ctx.getRegistry().read(ctx, warehouse);
+    ctx.getRegistry().read(warehouse);
 
     ctx.commit();
     final String json = JSON.serialize(warehouse);
@@ -199,12 +199,12 @@ public String readWarehouse(final TPCCContext ctx, final int w_id)
    */
   @Transaction(intent = Transaction.TYPE.EVALUATE)
   public String readOrder(final TPCCContext ctx, final int w_id, final int d_id, final int o_id)
-      throws EntityNotFoundException {
+      throws EntityNotFoundException, SerializationException {
     final String paramString = methodLogger.generateParamsString(ctx, w_id, d_id, o_id);
     methodLogger.logStart("readOrder", paramString);
 
     final Order order = Order.builder().w_id(w_id).d_id(d_id).id(o_id).build();
-    ctx.getRegistry().read(ctx, order);
+    ctx.getRegistry().read(order);
 
     ctx.commit();
     final String json = JSON.serialize(order);
@@ -220,12 +220,12 @@ public String readOrder(final TPCCContext ctx, final int w_id, final int d_id, f
    * @return The item with matchign I_ID
    */
   @Transaction(intent = Transaction.TYPE.EVALUATE)
-  public String readItem(final TPCCContext ctx, final int i_id) throws EntityNotFoundException {
+  public String readItem(final TPCCContext ctx, final int i_id) throws EntityNotFoundException, SerializationException {
     final String paramString = methodLogger.generateParamsString(ctx, i_id);
     methodLogger.logStart("readItem", paramString);
 
     final Item item = Item.builder().id(i_id).build();
-    ctx.getRegistry().read(ctx, item);
+    ctx.getRegistry().read(item);
 
     ctx.commit();
     final String json = JSON.serialize(item);
@@ -244,12 +244,12 @@ public String readItem(final TPCCContext ctx, final int i_id) throws EntityNotFo
    */
   @Transaction(intent = Transaction.TYPE.EVALUATE)
   public String readNewOrder(final TPCCContext ctx, final int w_id, final int d_id, final int o_id)
-      throws EntityNotFoundException {
+      throws EntityNotFoundException, SerializationException {
     final String paramString = methodLogger.generateParamsString(ctx, w_id, d_id, o_id);
     methodLogger.logStart("readNewOrder", paramString);
 
     final NewOrder newOrder = NewOrder.builder().w_id(w_id).d_id(d_id).o_id(o_id).build();
-    ctx.getRegistry().read(ctx, newOrder);
+    ctx.getRegistry().read(newOrder);
 
     ctx.commit();
     final String json = JSON.serialize(newOrder);
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Customer.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Customer.java
index 28cedff..737c5d5 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Customer.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Customer.java
@@ -1,9 +1,8 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.entity;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.KeyPart;
-import hu.bme.mit.ftsrg.chaincode.dataaccess.SerializableEntityBase;
+import hu.bme.mit.ftsrg.hypernate.entity.Entity;
+import hu.bme.mit.ftsrg.hypernate.entity.KeyPart;
 import lombok.EqualsAndHashCode;
 import org.hyperledger.fabric.contract.annotation.DataType;
 import org.hyperledger.fabric.contract.annotation.Property;
@@ -11,7 +10,7 @@
 /** Essentially, the CUSTOMER table. */
 @EqualsAndHashCode
 @DataType()
-public class Customer extends SerializableEntityBase<Customer> {
+public class Customer implements Entity<Customer> {
 
   /** The customer ID. Primary key. */
   @KeyPart
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/District.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/District.java
index 808e650..77343e1 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/District.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/District.java
@@ -1,9 +1,8 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.entity;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.KeyPart;
-import hu.bme.mit.ftsrg.chaincode.dataaccess.SerializableEntityBase;
+import hu.bme.mit.ftsrg.hypernate.entity.Entity;
+import hu.bme.mit.ftsrg.hypernate.entity.KeyPart;
 import lombok.EqualsAndHashCode;
 import org.hyperledger.fabric.contract.annotation.DataType;
 import org.hyperledger.fabric.contract.annotation.Property;
@@ -11,7 +10,7 @@
 /** Essentially, the DISTRICT table. */
 @EqualsAndHashCode
 @DataType()
-public final class District extends SerializableEntityBase<District> {
+public final class District implements Entity<District> {
 
   /** The district ID. Primary key. */
   @KeyPart
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/History.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/History.java
index 19dd98a..d16c22d 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/History.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/History.java
@@ -1,9 +1,8 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.entity;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.KeyPart;
-import hu.bme.mit.ftsrg.chaincode.dataaccess.SerializableEntityBase;
+import hu.bme.mit.ftsrg.hypernate.entity.Entity;
+import hu.bme.mit.ftsrg.hypernate.entity.KeyPart;
 import lombok.EqualsAndHashCode;
 import org.hyperledger.fabric.contract.annotation.DataType;
 import org.hyperledger.fabric.contract.annotation.Property;
@@ -11,7 +10,7 @@
 /** Essentially, the HISTORY table. */
 @EqualsAndHashCode
 @DataType
-public final class History extends SerializableEntityBase<History> {
+public final class History implements Entity<History> {
 
   /** The customer ID. Primary key. */
   @KeyPart
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Item.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Item.java
index 426b9db..ea9a67a 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Item.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Item.java
@@ -1,9 +1,8 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.entity;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.KeyPart;
-import hu.bme.mit.ftsrg.chaincode.dataaccess.SerializableEntityBase;
+import hu.bme.mit.ftsrg.hypernate.entity.Entity;
+import hu.bme.mit.ftsrg.hypernate.entity.KeyPart;
 import lombok.EqualsAndHashCode;
 import org.hyperledger.fabric.contract.annotation.DataType;
 import org.hyperledger.fabric.contract.annotation.Property;
@@ -11,7 +10,7 @@
 /** Essentially, the ITEM table. */
 @EqualsAndHashCode
 @DataType
-public final class Item extends SerializableEntityBase<Item> {
+public final class Item implements Entity<Item> {
 
   /** The ID of the item. Primary key. */
   @KeyPart
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/NewOrder.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/NewOrder.java
index 0133ce9..19115cc 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/NewOrder.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/NewOrder.java
@@ -1,9 +1,8 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.entity;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.KeyPart;
-import hu.bme.mit.ftsrg.chaincode.dataaccess.SerializableEntityBase;
+import hu.bme.mit.ftsrg.hypernate.entity.Entity;
+import hu.bme.mit.ftsrg.hypernate.entity.KeyPart;
 import lombok.EqualsAndHashCode;
 import org.hyperledger.fabric.contract.annotation.DataType;
 import org.hyperledger.fabric.contract.annotation.Property;
@@ -11,7 +10,7 @@
 /** Essentially, the NEW-ORDER table. */
 @EqualsAndHashCode
 @DataType
-public final class NewOrder extends SerializableEntityBase<NewOrder> {
+public final class NewOrder implements Entity<NewOrder> {
 
   /** The order ID. Primary key. */
   @KeyPart
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Order.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Order.java
index 8cb03f8..c638092 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Order.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Order.java
@@ -1,9 +1,8 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.entity;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.KeyPart;
-import hu.bme.mit.ftsrg.chaincode.dataaccess.SerializableEntityBase;
+import hu.bme.mit.ftsrg.hypernate.entity.Entity;
+import hu.bme.mit.ftsrg.hypernate.entity.KeyPart;
 import lombok.EqualsAndHashCode;
 import org.hyperledger.fabric.contract.annotation.DataType;
 import org.hyperledger.fabric.contract.annotation.Property;
@@ -11,7 +10,7 @@
 /** Essentially, the ORDER table. */
 @EqualsAndHashCode
 @DataType
-public final class Order extends SerializableEntityBase<Order> {
+public final class Order implements Entity<Order> {
 
   /** The order ID. Primary key. */
   @KeyPart
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/OrderLine.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/OrderLine.java
index d7e972e..fcce364 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/OrderLine.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/OrderLine.java
@@ -1,9 +1,8 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.entity;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.KeyPart;
-import hu.bme.mit.ftsrg.chaincode.dataaccess.SerializableEntityBase;
+import hu.bme.mit.ftsrg.hypernate.entity.Entity;
+import hu.bme.mit.ftsrg.hypernate.entity.KeyPart;
 import lombok.EqualsAndHashCode;
 import org.hyperledger.fabric.contract.annotation.DataType;
 import org.hyperledger.fabric.contract.annotation.Property;
@@ -11,7 +10,7 @@
 /** Essentially, the ORDER-LINE table. */
 @EqualsAndHashCode
 @DataType
-public final class OrderLine extends SerializableEntityBase<OrderLine> {
+public final class OrderLine implements Entity<OrderLine> {
 
   /** The order ID associated with the order line. Primary key. */
   @KeyPart
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Stock.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Stock.java
index 3c52aae..f5bb6a0 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Stock.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Stock.java
@@ -1,9 +1,8 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.entity;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.KeyPart;
-import hu.bme.mit.ftsrg.chaincode.dataaccess.SerializableEntityBase;
+import hu.bme.mit.ftsrg.hypernate.entity.Entity;
+import hu.bme.mit.ftsrg.hypernate.entity.KeyPart;
 import lombok.EqualsAndHashCode;
 import org.hyperledger.fabric.contract.annotation.DataType;
 import org.hyperledger.fabric.contract.annotation.Property;
@@ -11,7 +10,7 @@
 /** Essentially, the STOCK table. */
 @EqualsAndHashCode
 @DataType
-public final class Stock extends SerializableEntityBase<Stock> {
+public final class Stock implements Entity<Stock> {
 
   /** The ID of the item associated with the stock. Primary key. */
   @KeyPart
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Warehouse.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Warehouse.java
index 0eab617..16b0b64 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Warehouse.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/entity/Warehouse.java
@@ -1,9 +1,8 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.entity;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.KeyPart;
-import hu.bme.mit.ftsrg.chaincode.dataaccess.SerializableEntityBase;
+import hu.bme.mit.ftsrg.hypernate.entity.Entity;
+import hu.bme.mit.ftsrg.hypernate.entity.KeyPart;
 import lombok.EqualsAndHashCode;
 import org.hyperledger.fabric.contract.annotation.DataType;
 import org.hyperledger.fabric.contract.annotation.Property;
@@ -11,7 +10,7 @@
 /** Essentially, the WAREHOUSE table. */
 @EqualsAndHashCode
 @DataType
-public class Warehouse extends SerializableEntityBase<Warehouse> {
+public class Warehouse implements Entity<Warehouse> {
 
   /** The warehouse ID. Primary key. */
   @KeyPart
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/extra/DeliveredOrder.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/extra/DeliveredOrder.java
index 201c48a..0c73764 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/extra/DeliveredOrder.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/extra/DeliveredOrder.java
@@ -1,5 +1,4 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.extra;
 
 import hu.bme.mit.ftsrg.chaincode.tpcc.data.output.DeliveryOutput;
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/extra/ItemsData.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/extra/ItemsData.java
index 87874ec..6e4ee9a 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/extra/ItemsData.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/extra/ItemsData.java
@@ -1,5 +1,4 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.extra;
 
 import hu.bme.mit.ftsrg.chaincode.tpcc.data.output.NewOrderOutput;
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/extra/OrderLineData.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/extra/OrderLineData.java
index fac8e5c..c8c6c8c 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/extra/OrderLineData.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/extra/OrderLineData.java
@@ -1,5 +1,4 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.extra;
 
 import hu.bme.mit.ftsrg.chaincode.tpcc.data.entity.OrderLine;
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/input/DeliveryInput.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/input/DeliveryInput.java
index fa952d8..4fd0c72 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/input/DeliveryInput.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/input/DeliveryInput.java
@@ -1,5 +1,4 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.input;
 
 import lombok.EqualsAndHashCode;
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/input/NewOrderInput.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/input/NewOrderInput.java
index 0d1c923..2272094 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/input/NewOrderInput.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/input/NewOrderInput.java
@@ -1,5 +1,4 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.input;
 
 import lombok.EqualsAndHashCode;
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/input/OrderStatusInput.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/input/OrderStatusInput.java
index 298da91..c204f8b 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/input/OrderStatusInput.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/input/OrderStatusInput.java
@@ -1,5 +1,4 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.input;
 
 import lombok.EqualsAndHashCode;
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/input/PaymentInput.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/input/PaymentInput.java
index bb80d94..7a2b2a1 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/input/PaymentInput.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/input/PaymentInput.java
@@ -1,5 +1,4 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.input;
 
 import lombok.EqualsAndHashCode;
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/input/StockLevelInput.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/input/StockLevelInput.java
index 8c1d792..bc9ac24 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/input/StockLevelInput.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/input/StockLevelInput.java
@@ -1,5 +1,4 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.input;
 
 import lombok.EqualsAndHashCode;
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/output/DeliveryOutput.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/output/DeliveryOutput.java
index 1860868..83b2fc6 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/output/DeliveryOutput.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/output/DeliveryOutput.java
@@ -1,5 +1,4 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.output;
 
 import hu.bme.mit.ftsrg.chaincode.tpcc.data.extra.DeliveredOrder;
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/output/NewOrderOutput.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/output/NewOrderOutput.java
index 05535a8..3a30785 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/output/NewOrderOutput.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/output/NewOrderOutput.java
@@ -1,5 +1,4 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.output;
 
 import hu.bme.mit.ftsrg.chaincode.tpcc.data.entity.Customer;
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/output/OrderStatusOutput.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/output/OrderStatusOutput.java
index 1877a38..0225bcc 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/output/OrderStatusOutput.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/output/OrderStatusOutput.java
@@ -1,5 +1,4 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.output;
 
 import hu.bme.mit.ftsrg.chaincode.tpcc.data.entity.Customer;
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/output/PaymentOutput.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/output/PaymentOutput.java
index 35e81cf..30398bb 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/output/PaymentOutput.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/output/PaymentOutput.java
@@ -1,5 +1,4 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.output;
 
 import hu.bme.mit.ftsrg.chaincode.tpcc.data.entity.Customer;
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/output/StockLevelOutput.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/output/StockLevelOutput.java
index b084c5c..48e6309 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/output/StockLevelOutput.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/data/output/StockLevelOutput.java
@@ -1,5 +1,4 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.data.output;
 
 import hu.bme.mit.ftsrg.chaincode.tpcc.data.input.StockLevelInput;
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/middleware/LoggingStubMiddleware.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/middleware/LoggingStubMiddleware.java
index 3f93699..70fac07 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/middleware/LoggingStubMiddleware.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/middleware/LoggingStubMiddleware.java
@@ -1,6 +1,7 @@
+/* SPDX-License-Identifier: Apache-2.0 */
 package hu.bme.mit.ftsrg.chaincode.tpcc.middleware;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.ChaincodeStubMiddlewareBase;
+import hu.bme.mit.ftsrg.hypernate.middleware.ChaincodeStubMiddlewareBase;
 import java.util.Arrays;
 import org.hyperledger.fabric.shim.ChaincodeStub;
 import org.slf4j.Logger;
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/middleware/TPCCContext.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/middleware/TPCCContext.java
index 21a0657..77a55e8 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/middleware/TPCCContext.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/middleware/TPCCContext.java
@@ -1,6 +1,7 @@
+/* SPDX-License-Identifier: Apache-2.0 */
 package hu.bme.mit.ftsrg.chaincode.tpcc.middleware;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.ContextWithRegistry;
+import hu.bme.mit.ftsrg.hypernate.context.ContextWithRegistry;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.Deque;
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/middleware/UpdateThrottledChaincodeStubMiddleware.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/middleware/UpdateThrottledChaincodeStubMiddleware.java
index 8759ef6..b8a7149 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/middleware/UpdateThrottledChaincodeStubMiddleware.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/middleware/UpdateThrottledChaincodeStubMiddleware.java
@@ -1,8 +1,7 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.middleware;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.ChaincodeStubMiddlewareBase;
+import hu.bme.mit.ftsrg.hypernate.middleware.ChaincodeStubMiddlewareBase;
 import org.hyperledger.fabric.shim.ChaincodeStub;
 
 /**
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/middleware/WriteBackCachedChaincodeStubMiddleware.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/middleware/WriteBackCachedChaincodeStubMiddleware.java
index 9abd4c2..c609c15 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/middleware/WriteBackCachedChaincodeStubMiddleware.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/middleware/WriteBackCachedChaincodeStubMiddleware.java
@@ -1,8 +1,7 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.middleware;
 
-import hu.bme.mit.ftsrg.chaincode.dataaccess.ChaincodeStubMiddlewareBase;
+import hu.bme.mit.ftsrg.hypernate.middleware.ChaincodeStubMiddlewareBase;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
diff --git a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/util/JSON.java b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/util/JSON.java
index afcb0d6..d340d05 100644
--- a/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/util/JSON.java
+++ b/smart-contract/hyperledger-fabric/v2/java/src/main/java/hu/bme/mit/ftsrg/chaincode/tpcc/util/JSON.java
@@ -1,5 +1,4 @@
 /* SPDX-License-Identifier: Apache-2.0 */
-
 package hu.bme.mit.ftsrg.chaincode.tpcc.util;
 
 import com.google.gson.Gson;