Clean up the registerd logger handlers when stopping the plugin (#311)

Signed-off-by: Jinbo Wang <[email protected]>

Author: testforstephen

com.microsoft.java.debug.plugin/src/main/java/com/microsoft/java/debug/plugin/internal/JavaDebuggerServerPlugin.java

@@ -35,6 +35,7 @@ public void start(BundleContext context) throws Exception {
     @Override
     public void stop(BundleContext context) throws Exception {
         logger.info("Stopping " + PLUGIN_ID);
+        LogUtils.cleanupHandlers();
     }
 
 }

com.microsoft.java.debug.plugin/src/main/java/com/microsoft/java/debug/plugin/internal/LogUtils.java

@@ -11,6 +11,7 @@
 
 package com.microsoft.java.debug.plugin.internal;
 
+import java.util.logging.Handler;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -32,6 +33,21 @@ public static void initialize(Level level) {
         logger.setLevel(level);
     }
 
+    /**
+     * Remove the logger handlers registered to the global logger.
+     */
+    public static void cleanupHandlers() {
+        Handler[] handlers = logger.getHandlers();
+        for (Handler handler : handlers) {
+            logger.removeHandler(handler);
+        }
+
+        Handler[] usageHandlers = usageDataLogger.getHandlers();
+        for (Handler handler : usageHandlers) {
+            usageDataLogger.removeHandler(handler);
+        }
+    }
+
     /**
      * Configure log level setting for java debugger.
      *