Abstracted logger to fall back to native if Log4J isn't present

build.gradle

@@ -1,5 +1,6 @@
 plugins {
     id 'java'
+    id "com.github.johnrengelman.shadow" version "8.1.1" apply false
 }
 
 subprojects {

core/build.gradle

@@ -1,4 +1,5 @@
 apply plugin: 'java-library'
+apply plugin: 'com.github.johnrengelman.shadow'
 
 dependencies {
     implementation 'com.google.code.gson:gson:2.10.1'

core/src/main/java/io/dogboy/serializationisbad/core/SerializationIsBad.java

@@ -2,16 +2,17 @@
 
 import com.google.gson.Gson;
 import io.dogboy.serializationisbad.core.config.SIBConfig;
-import org.apache.logging.log4j.LogManager;
-import org.apache.logging.log4j.Logger;
+import io.dogboy.serializationisbad.core.logger.ILogger;
+import io.dogboy.serializationisbad.core.logger.Log4JLogger;
+import io.dogboy.serializationisbad.core.logger.NativeLogger;
 
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.InputStreamReader;
 import java.nio.charset.StandardCharsets;
 
 public class SerializationIsBad {
-    public static final Logger logger = LogManager.getLogger(SerializationIsBad.class);
+    public static final ILogger logger = initLogger("SerializationIsBad");
     private static SerializationIsBad instance;
     private static boolean agentActive = false;
 
@@ -35,6 +36,18 @@ public static void init(File minecraftDir) {
         SerializationIsBad.instance = new SerializationIsBad(minecraftDir);
     }
 
+    private static ILogger initLogger(String name) {
+        try {
+            // Check if needed Log4J classes are available
+            Class.forName("org.apache.logging.log4j.LogManager");
+            Class.forName("org.apache.logging.log4j.Logger");
+            return new Log4JLogger(name);
+        } catch (ClassNotFoundException e) {
+            // Fallback to Java native logger
+            return new NativeLogger(name);
+        }
+    }
+
     private final SIBConfig config;
 
     private SerializationIsBad(File minecraftDir) {

core/src/main/java/io/dogboy/serializationisbad/core/logger/ILogger.java

@@ -0,0 +1,8 @@
+package io.dogboy.serializationisbad.core.logger;
+
+public interface ILogger {
+    void debug(String message);
+    void info(String message);
+    void warn(String message);
+    void error(String message, Throwable throwable);
+}

core/src/main/java/io/dogboy/serializationisbad/core/logger/Log4JLogger.java

@@ -0,0 +1,31 @@
+package io.dogboy.serializationisbad.core.logger;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+public class Log4JLogger implements ILogger {
+    private final Logger logger;
+
+    public Log4JLogger(String name) {
+        this.logger = LogManager.getLogger(name);
+    }
+    @Override
+    public void debug(String message) {
+        logger.debug(message);
+    }
+
+    @Override
+    public void info(String message) {
+        logger.info(message);
+    }
+
+    @Override
+    public void warn(String message) {
+        logger.warn(message);
+    }
+
+    @Override
+    public void error(String message, Throwable throwable) {
+        logger.error(message, throwable);
+    }
+}

core/src/main/java/io/dogboy/serializationisbad/core/logger/NativeLogger.java

@@ -0,0 +1,32 @@
+package io.dogboy.serializationisbad.core.logger;
+
+import java.util.logging.Logger;
+
+public class NativeLogger implements ILogger {
+    private final Logger logger;
+
+    public NativeLogger(String name) {
+        this.logger = Logger.getLogger(name);
+    }
+
+    @Override
+    public void debug(String message) {
+        logger.finest(message);
+    }
+
+    @Override
+    public void info(String message) {
+        logger.info(message);
+    }
+
+    @Override
+    public void warn(String message) {
+        logger.warning(message);
+    }
+
+    @Override
+    public void error(String message, Throwable throwable) {
+        logger.severe(message);
+        throwable.printStackTrace();
+    }
+}