add dispose method in PluginClassLoader

pf4j/src/main/java/ro/fortsoft/pf4j/DefaultPluginManager.java

@@ -411,11 +411,7 @@ public class DefaultPluginManager implements PluginManager {
     		// remove the classloader
     		if (pluginClassLoaders.containsKey(pluginId)) {
     			PluginClassLoader classLoader = pluginClassLoaders.remove(pluginId);
-    			try {
+                classLoader.dispose();
-    				classLoader.close();
-    			} catch (IOException e) {
-    				log.error(e.getMessage(), e);
-    			}
     		}
 
     		return true;
@@ -803,6 +799,7 @@ public class DefaultPluginManager implements PluginManager {
             unzip.setDestination(pluginDirectory);
             unzip.extract();
         }
+
         return pluginDirectory;
     }
 

pf4j/src/main/java/ro/fortsoft/pf4j/PluginClassLoader.java

@@ -12,6 +12,10 @@
  */
 package ro.fortsoft.pf4j;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.util.List;
@@ -23,6 +27,8 @@ import java.util.List;
  */
 public class PluginClassLoader extends URLClassLoader {
 
+    private static final Logger log = LoggerFactory.getLogger(PluginClassLoader.class);
+
 //	private static final String JAVA_PACKAGE_PREFIX = "java.";
 //	private static final String JAVAX_PACKAGE_PREFIX = "javax.";
 	private static final String PLUGIN_PACKAGE_PREFIX = "ro.fortsoft.pf4j.";
@@ -90,4 +96,19 @@ public class PluginClassLoader extends URLClassLoader {
         // use the standard URLClassLoader (which follows normal parent delegation)
         return super.loadClass(className);
     }
+
+    /**
+     * Release all resources acquired by this class loader.
+     * The current implementation is incomplete.
+     * For now, this instance can no longer be used to load
+     * new classes or resources that are defined by this loader.
+     */
+    public void dispose() {
+        try {
+            close();
+        } catch (IOException e) {
+            log.error(e.getMessage(), e);
+        }
+    }
+
 }