From 6d844ffbb6cda4c34695187037495f7d45bb8614 Mon Sep 17 00:00:00 2001
From: games647 <games647@users.noreply.github.com>
Date: Thu, 12 Jan 2023 14:31:33 +0100
Subject: [PATCH] Forward SLF4J log messages to plugin logger

Related #172
---
 pom.xml                                       | 21 +++-----
 .../games647/lagmonitor/LagMonitor.java       |  3 ++
 .../lagmonitor/logging/ForwardLogService.java | 39 +++++++++++++++
 .../logging/ForwardingLoggerFactory.java      | 48 +++++++++++++++++++
 .../org.slf4j.spi.SLF4JServiceProvider        |  1 +
 5 files changed, 98 insertions(+), 14 deletions(-)
 create mode 100644 src/main/java/com/github/games647/lagmonitor/logging/ForwardLogService.java
 create mode 100644 src/main/java/com/github/games647/lagmonitor/logging/ForwardingLoggerFactory.java
 create mode 100644 src/main/resources/META-INF/services/org.slf4j.spi.SLF4JServiceProvider

diff --git a/pom.xml b/pom.xml
index 0b2dbb4..04225fb 100644
--- a/pom.xml
+++ b/pom.xml
@@ -62,10 +62,6 @@
                                 <exclude>oshi.vmmacaddr.properties</exclude>
                             </excludes>
                         </relocation>
-                        <relocation>
-                            <pattern>org.slf4j</pattern>
-                            <shadedPattern>lagmonitor.slf4j</shadedPattern>
-                        </relocation>
                     </relocations>
                     <artifactSet>
                         <excludes>
@@ -140,16 +136,6 @@
             <artifactId>paper-api</artifactId>
             <version>1.19-R0.1-SNAPSHOT</version>
             <scope>provided</scope>
-            <exclusions>
-                <exclusion>
-                    <groupId>org.slf4j</groupId>
-                    <artifactId>*</artifactId>
-                </exclusion>
-                <exclusion>
-                    <groupId>net.md-5</groupId>
-                    <artifactId>*</artifactId>
-                </exclusion>
-            </exclusions>
         </dependency>
 
         <!--Server API for Spigot-->
@@ -179,6 +165,13 @@
             </exclusions>
         </dependency>
 
+        <!-- JDK logging bridge to forward logging messages to the plugin logger -->
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-jdk14</artifactId>
+            <version>2.0.6</version>
+        </dependency>
+
         <!-- Include core explicitly in order to ship the default configuration files in it -->
         <dependency>
             <groupId>com.github.oshi</groupId>
diff --git a/src/main/java/com/github/games647/lagmonitor/LagMonitor.java b/src/main/java/com/github/games647/lagmonitor/LagMonitor.java
index e5a54f1..9201e9d 100644
--- a/src/main/java/com/github/games647/lagmonitor/LagMonitor.java
+++ b/src/main/java/com/github/games647/lagmonitor/LagMonitor.java
@@ -23,6 +23,7 @@
 import com.github.games647.lagmonitor.listener.GraphListener;
 import com.github.games647.lagmonitor.listener.PageManager;
 import com.github.games647.lagmonitor.listener.ThreadSafetyListener;
+import com.github.games647.lagmonitor.logging.ForwardingLoggerFactory;
 import com.github.games647.lagmonitor.storage.MonitorSaveTask;
 import com.github.games647.lagmonitor.storage.NativeSaveTask;
 import com.github.games647.lagmonitor.storage.Storage;
@@ -68,6 +69,8 @@ public class LagMonitor extends JavaPlugin {
 
     @Override
     public void onLoad() {
+        ForwardingLoggerFactory.PARENT_LOGGER = getLogger();
+
         nativeData.setupNativeAdapter();
     }
 
diff --git a/src/main/java/com/github/games647/lagmonitor/logging/ForwardLogService.java b/src/main/java/com/github/games647/lagmonitor/logging/ForwardLogService.java
new file mode 100644
index 0000000..61b8050
--- /dev/null
+++ b/src/main/java/com/github/games647/lagmonitor/logging/ForwardLogService.java
@@ -0,0 +1,39 @@
+package com.github.games647.lagmonitor.logging;
+
+import org.slf4j.ILoggerFactory;
+import org.slf4j.IMarkerFactory;
+import org.slf4j.jul.JULServiceProvider;
+import org.slf4j.spi.MDCAdapter;
+import org.slf4j.spi.SLF4JServiceProvider;
+
+public class ForwardLogService implements SLF4JServiceProvider {
+
+    private ILoggerFactory loggerFactory;
+    private JULServiceProvider delegate;
+
+    public ILoggerFactory getLoggerFactory() {
+        return this.loggerFactory;
+    }
+
+    public IMarkerFactory getMarkerFactory() {
+        return delegate.getMarkerFactory();
+    }
+
+    public MDCAdapter getMDCAdapter() {
+        return delegate.getMDCAdapter();
+    }
+
+    @Override
+    public String getRequesteApiVersion() {
+        return delegate.getRequestedApiVersion();
+    }
+
+    public String getRequestedApiVersion() {
+        return delegate.getRequestedApiVersion();
+    }
+
+    public void initialize() {
+        this.delegate = new JULServiceProvider();
+        this.loggerFactory = new ForwardingLoggerFactory();
+    }
+}
diff --git a/src/main/java/com/github/games647/lagmonitor/logging/ForwardingLoggerFactory.java b/src/main/java/com/github/games647/lagmonitor/logging/ForwardingLoggerFactory.java
new file mode 100644
index 0000000..f05d26a
--- /dev/null
+++ b/src/main/java/com/github/games647/lagmonitor/logging/ForwardingLoggerFactory.java
@@ -0,0 +1,48 @@
+package com.github.games647.lagmonitor.logging;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
+import org.slf4j.ILoggerFactory;
+import org.slf4j.Logger;
+import org.slf4j.jul.JDK14LoggerAdapter;
+
+public class ForwardingLoggerFactory implements ILoggerFactory {
+
+    private final ConcurrentMap<String, Logger> loggerMap = new ConcurrentHashMap<>();
+
+    public static java.util.logging.Logger PARENT_LOGGER;
+
+    @Override
+    public Logger getLogger(String name) {
+        return loggerMap.computeIfAbsent(name, key -> {
+            java.util.logging.Logger julLogger;
+            if (PARENT_LOGGER == null) {
+                julLogger = java.util.logging.Logger.getLogger(name);
+            } else {
+                julLogger = PARENT_LOGGER;
+            }
+
+            Logger newInstance = null;
+            try {
+                newInstance = createJDKLogger(julLogger);
+            } catch (NoSuchMethodException | InvocationTargetException |
+                     InstantiationException | IllegalAccessException e) {
+                e.printStackTrace();
+                System.out.println("Failed to created logging instance");
+            }
+
+            return newInstance;
+        });
+    }
+
+    protected static Logger createJDKLogger(java.util.logging.Logger parent)
+            throws NoSuchMethodException, InstantiationException, IllegalAccessException, InvocationTargetException {
+        Class<?> adapterClass = JDK14LoggerAdapter.class;
+        Constructor<?> cons = adapterClass.getDeclaredConstructor(java.util.logging.Logger.class);
+        cons.setAccessible(true);
+        return (Logger) cons.newInstance(parent);
+    }
+}
diff --git a/src/main/resources/META-INF/services/org.slf4j.spi.SLF4JServiceProvider b/src/main/resources/META-INF/services/org.slf4j.spi.SLF4JServiceProvider
new file mode 100644
index 0000000..1149156
--- /dev/null
+++ b/src/main/resources/META-INF/services/org.slf4j.spi.SLF4JServiceProvider
@@ -0,0 +1 @@
+com.github.games647.lagmonitor.logging.ForwardLogService