Add extension jackson-jr-extension-javatime to support (some) Java 8 date/time types

README.md

@@ -40,6 +40,7 @@ Project is composed of multiple Maven sub-modules, each corresponding to a jar:
 * [jr-retrofit2](../../tree/master/jr-retrofit2) contains `jackson-jr` - based handlers for [Retrofit 2](https://square.github.io/retrofit/) library
     * Depends on `jackson-jr` and `Retrofit` API jars, and indirectly on `jackson-core`
 * [jr-annotation-support](../../tree/master/jr-annotation-support) contains extension with support for a subset of core [Jackson annotations](../../../jackson-annotations)
+* [jr-extension-javatime](../../tree/master/jr-extension-javatime) contains extension with support for a subset of Java 8 Date/Time types (e.g. `LocalDateTime`)
 * jr-all creates an "uber-jar" that contains individual modules along with all their dependencies:
     * `jr-objects` classes as-is, without relocating
     * `jr-stree` classes as-is, without relocating

jr-extension-javatime/README.md

@@ -0,0 +1,54 @@
+## Overview
+
+This module extends the functionality of jackson-jr by adding support for (a subset of) Java 8 Date/Time types (value types in JDK `java.time` package).
+
+### Status
+
+Added in Jackson 2.17.
+
+### Usage
+To be able to use supported annotations, you need to register extension like so:
+```java
+    private static final JSON JACKSON = JSON.builder()
+        .register(new JacksonJrJavaTimeExtension())
+        .build();
+```
+after which you can use normal read and write operations as usual:
+
+```java
+import java.time.LocalDateTime;
+
+public class Application {
+    public static void main(String[] args) {
+        final LocalDateTime now = LocalDateTime.now();
+        MyClass myObject = new MyClass(now, 'Some Other Values....');
+        String myObjectJsonString = JACKSON.asString(myObject);
+        MyClass myObjectFromJson = JACKSON.beanFrom(MyClass, myObjectJsonString);
+        assert myObjectFromJson.getTime().equals(now);
+    }
+}
+
+// ...
+
+public class MyClass {
+    private LocalDateTime time;
+    private String otherItems;
+
+    public MyClass(LocalDateTime datetime, String others) {
+        //...
+    }
+
+    public LocalDateTime getTime() {
+        return time;
+    }
+    // other getters & setters
+}
+```
+
+### Date Classes currently supported by `JacksonJrJavaTimeExtension`
+
+- `java.util.LocalDateTime`
+
+### Plans for Future
+
+- Add support for other Java 8 Date/Time types

jr-extension-javatime/pom.xml

@@ -0,0 +1,71 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <!-- This module was also published with a richer model, Gradle metadata,  -->
+    <!-- which should be used instead. Do not delete the following line which  -->
+    <!-- is to indicate to Gradle or any Gradle module metadata file consumer  -->
+    <!-- that they should prefer consuming it instead. -->
+    <!-- do_not_remove: published-with-gradle-metadata -->
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>com.fasterxml.jackson.jr</groupId>
+        <artifactId>jackson-jr-parent</artifactId>
+        <version>2.17.0-rc1-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>jackson-jr-extension-javatime</artifactId>
+    <packaging>bundle</packaging>
+    <description>Jackson-jr extension that adds support for Java 8 Date/Time value types such as `java.util.LocalDateTime`</description>
+    <url>https://github.com/FasterXML/jackson-jr</url>
+
+    <licenses>
+        <license>
+            <name>The Apache Software License, Version 2.0</name>
+            <url>https://www.apache.org/licenses/LICENSE-2.0.txt</url>
+            <distribution>repo</distribution>
+        </license>
+    </licenses>
+
+    <properties>
+        <!-- Looks like we need to be bit careful on OSGi exports, to avoid
+            accidentally double-exporting jr-objects types
+          -->
+        <osgi.export>${project.groupId}.extension.javatime;version=${project.version}</osgi.export>
+
+        <!-- for Reproducible Builds -->
+        <project.build.outputTimestamp>2023-11-15T22:39:39Z</project.build.outputTimestamp>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.fasterxml.jackson.jr</groupId>
+            <artifactId>jackson-jr-objects</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <configuration>
+                    <redirectTestOutputToFile>${surefire.redirectTestOutputToFile}</redirectTestOutputToFile>
+                    <excludes>
+                        <exclude>**/failing/*.java</exclude>
+                    </excludes>
+                </configuration>
+            </plugin>
+            <!-- 11-Mar-2019, tatu: Add basic JDK8-includable module-info, generated by Moditect -->
+            <plugin>
+                <groupId>org.moditect</groupId>
+                <artifactId>moditect-maven-plugin</artifactId>
+            </plugin>
+            <!-- 05-Jul-2020, tatu: Add generation of Gradle Module Metadata -->
+            <plugin>
+                <groupId>de.jjohannes</groupId>
+                <artifactId>gradle-module-metadata-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

jr-extension-javatime/src/main/java/com/fasterxml/jackson/jr/extension/javatime/JacksonJrJavaTimeExtension.java

@@ -0,0 +1,20 @@
+package com.fasterxml.jackson.jr.extension.javatime;
+
+import com.fasterxml.jackson.jr.ob.JacksonJrExtension;
+import com.fasterxml.jackson.jr.ob.api.ExtensionContext;
+
+public class JacksonJrJavaTimeExtension extends JacksonJrExtension {
+    final static JavaTimeReaderWriterProvider DEFAULT_RW_PROVIDER = new JavaTimeReaderWriterProvider();
+
+    private JavaTimeReaderWriterProvider readerWriterProvider = DEFAULT_RW_PROVIDER;
+
+    @Override
+    protected void register(ExtensionContext ctxt) {
+        ctxt.insertProvider(readerWriterProvider);
+    }
+
+    public JacksonJrJavaTimeExtension with(JavaTimeReaderWriterProvider p) {
+        readerWriterProvider = p;
+        return this;
+    }
+}

jr-extension-javatime/src/main/java/com/fasterxml/jackson/jr/extension/javatime/JavaTimeReaderWriterProvider.java

@@ -0,0 +1,48 @@
+package com.fasterxml.jackson.jr.extension.javatime;
+
+import com.fasterxml.jackson.jr.ob.api.ReaderWriterProvider;
+import com.fasterxml.jackson.jr.ob.api.ValueReader;
+import com.fasterxml.jackson.jr.ob.api.ValueWriter;
+import com.fasterxml.jackson.jr.ob.impl.JSONReader;
+import com.fasterxml.jackson.jr.ob.impl.JSONWriter;
+
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+
+/**
+ * Provider for {@link ValueReader}s and {@link ValueWriter}s for Date/Time
+ * types supported by Java Time Extension.
+ */
+public class JavaTimeReaderWriterProvider extends ReaderWriterProvider
+{
+    private DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ISO_LOCAL_DATE_TIME;
+
+    public JavaTimeReaderWriterProvider() { }
+
+    @Override
+    public ValueReader findValueReader(JSONReader readContext, Class<?> type) {
+        return LocalDateTime.class.isAssignableFrom(type) ? new LocalDateTimeValueReader(dateTimeFormatter) : null;
+    }
+
+    @Override
+    public ValueWriter findValueWriter(JSONWriter writeContext, Class<?> type) {
+        return LocalDateTime.class.isAssignableFrom(type) ? new LocalDateTimeValueWriter(dateTimeFormatter) : null;
+    }
+
+    /**
+     * Method for reconfiguring {@link DateTimeFormatter} used for reading/writing
+     * following Date/Time value types:
+     *<ul>
+     * <li>{@code java.time.LocalDateTime}
+     *  </li>
+     *</ul>
+     * 
+     * @param formatter
+     *
+     * @return This provider instance for call chaining
+     */
+    public JavaTimeReaderWriterProvider withDateTimeFormatter(DateTimeFormatter formatter) {
+        dateTimeFormatter = formatter;
+        return this;
+    }
+}

jr-extension-javatime/src/main/java/com/fasterxml/jackson/jr/extension/javatime/LocalDateTimeValueReader.java

@@ -0,0 +1,23 @@
+package com.fasterxml.jackson.jr.extension.javatime;
+
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.jr.ob.api.ValueReader;
+import com.fasterxml.jackson.jr.ob.impl.JSONReader;
+
+import java.io.IOException;
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+
+public class LocalDateTimeValueReader extends ValueReader {
+    private final DateTimeFormatter formatter;
+
+    public LocalDateTimeValueReader(DateTimeFormatter formatter) {
+        super(LocalDateTime.class);
+        this.formatter = formatter;
+    }
+
+    @Override
+    public Object read(JSONReader reader, JsonParser p) throws IOException {
+        return LocalDateTime.parse(p.getText(), formatter);
+    }
+}

jr-extension-javatime/src/main/java/com/fasterxml/jackson/jr/extension/javatime/LocalDateTimeValueWriter.java

@@ -0,0 +1,28 @@
+package com.fasterxml.jackson.jr.extension.javatime;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.jr.ob.api.ValueWriter;
+import com.fasterxml.jackson.jr.ob.impl.JSONWriter;
+
+import java.io.IOException;
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+
+public class LocalDateTimeValueWriter implements ValueWriter {
+    private final DateTimeFormatter formatter;
+
+    public LocalDateTimeValueWriter(DateTimeFormatter formatter) {
+        this.formatter = formatter;
+    }
+
+    @Override
+    public void writeValue(JSONWriter context, JsonGenerator g, Object value) throws IOException {
+        String localDateTimeString = ((LocalDateTime) value).format(formatter);
+        context.writeValue(localDateTimeString);
+    }
+
+    @Override
+    public Class<?> valueType() {
+        return LocalDateTime.class;
+    }
+}

jr-extension-javatime/src/main/resources/META-INF/LICENSE

@@ -0,0 +1,8 @@
+This copy of Jackson-jr library is licensed under the
+Apache (Software) License, version 2.0 ("the License").
+See the License for details about distribution rights, and the
+specific rights regarding derivative works.
+
+You may obtain a copy of the License at:
+
+http://www.apache.org/licenses/LICENSE-2.0

jr-extension-javatime/src/main/resources/META-INF/NOTICE

@@ -0,0 +1,17 @@
+# Jackson JSON processor
+
+Jackson is a high-performance, Free/Open Source JSON processing library.
+It was originally written by Tatu Saloranta (tatu.saloranta@iki.fi), and has
+been in development since 2007.
+It is currently developed by a community of developers.
+
+## Licensing
+
+Jackson components are licensed under Apache (Software) License, version 2.0,
+as per accompanying LICENSE file.
+
+## Credits
+
+A list of contributors may be found from CREDITS file, which is included
+in some artifacts (usually source distributions); but is always available
+from the source code management (SCM) system project uses.

jr-extension-javatime/src/moditect/module-info.java

@@ -0,0 +1,6 @@
+module com.fasterxml.jackson.jr.extension.javatime {
+    requires com.fasterxml.jackson.core;
+    requires com.fasterxml.jackson.jr.ob;
+
+    exports com.fasterxml.jackson.jr.extension.javatime;
+}

pom.xml

@@ -25,6 +25,7 @@
     <module>jr-retrofit2</module>
     <module>jr-stree</module>
     <module>jr-annotation-support</module>
+    <module>jr-extension-javatime</module>
     <module>jr-all</module>
   </modules>
 

release-notes/CREDITS-2.x

@@ -39,3 +39,8 @@ Julian Honnen (@jhonnen)
 * Reported #112: `overrideStandardValueWriter` only applied to first `java.nio.file.Path`
   valued field of bean
  (2.17.0)
+
+@Shounaks
+
+* Contributed implf ro #100: Add support for `java.time` (Java 8 date/time) types
+ (2.17.0)

release-notes/VERSION-2.x

@@ -15,6 +15,9 @@ Modules:
 
 #78: Deserializes "null" to "0.0" for `java.lang.Double` (wrapper)
  (reported by @bill-phast)
+#100: Add support for `java.time` (Java 8 date/time) types
+ (requested by @sebastian-zero)
+ (contributed by @Shounaks) 
 #112: `overrideStandardValueWriter` only applied to first `java.nio.file.Path`
   valued field of bean
  (reported by Julian H)