Allow classes to be loaded via plugin loader

When a plugin is used, additional RMI classes may be added to the
codebase. These need to be taken into account when loading remote
objects from the RMI registry.

src/eu/tneitzel/rmg/internal/CodebaseCollector.java

@@ -7,6 +7,7 @@
 import java.util.HashSet;
 import java.util.Set;
 
+import eu.tneitzel.rmg.plugin.PluginSystem;
 import eu.tneitzel.rmg.utils.RMGUtils;
 import javassist.CannotCompileException;
 import javassist.NotFoundException;
@@ -87,18 +88,42 @@ public class CodebaseCollector extends RMIClassLoaderSpi
      */
     public Class<?> loadClass(String codebase, String name, ClassLoader defaultLoader) throws MalformedURLException, ClassNotFoundException
     {
-        Class<?> resolvedClass = null;
-        long serialVersionUID = RMGOption.SERIAL_VERSION_UID.getValue();
-
         addCodebase(codebase, name);
         codebase = null;
 
+        long serialVersionUID = RMGOption.SERIAL_VERSION_UID.getValue();
+
         if (serialVersionUIDMap.containsKey(name))
         {
             serialVersionUID = serialVersionUIDMap.get(name);
             name = "_" + name;
         }
 
+        else
+        {
+            try
+            {
+                // attempt to load the class directly
+                return originalLoader.loadClass(codebase, name, defaultLoader);
+            }
+
+            catch (ClassNotFoundException e) {}
+
+            if (PluginSystem.pluginLoader != null)
+            {
+                try
+                {
+                    // if a plugin is used attempt to load the class via the plugin loader
+                    return originalLoader.loadClass(codebase, name, PluginSystem.pluginLoader);
+                }
+
+                catch (ClassNotFoundException e) {}
+            }
+        }
+
+        // class could neither be loaded directly nor via plugin. Dynamic creation is required.
+        Class<?> resolvedClass = null;
+
         try
         {
             if (name.endsWith("_Stub"))
@@ -147,19 +172,47 @@ else if (name.contains("SocketFactory") || name.endsWith("Factory") || name.ends
      */
     public Class<?> loadProxyClass(String codebase, String[] interfaces, ClassLoader defaultLoader) throws MalformedURLException, ClassNotFoundException
     {
+        for (String intf : interfaces)
+        {
+            addCodebase(codebase, intf);
+        }
+
+        codebase = null;
         Class<?> resolvedClass = null;
 
-        try {
+        try
+        {
+            // attempt to load the class directly without dynamic class creation
+            return originalLoader.loadProxyClass(codebase, interfaces, defaultLoader);
+        }
+
+        catch (ClassNotFoundException e) {}
+
+        if (PluginSystem.pluginLoader != null)
+        {
+            try
+            {
+                // if a plugin is used, attempt to load the class from the plugin loader
+                return originalLoader.loadProxyClass(codebase, interfaces, PluginSystem.pluginLoader);
+            }
+
+            catch (ClassNotFoundException e) {}
+        }
 
-            for(String intf : interfaces) {
+        try
+        {
+            // the class could neither be loaded directly nor via plugin. Dynamic creation is required
+            for (String intf : interfaces)
+            {
                 RMGUtils.makeInterface(intf);
-                addCodebase(codebase, intf);
             }
 
-            codebase = null;
             resolvedClass = originalLoader.loadProxyClass(codebase, interfaces, defaultLoader);
 
-        } catch (CannotCompileException e) {
+        }
+
+        catch (CannotCompileException e)
+        {
             ExceptionHandler.internalError("loadProxyClass", "Unable to compile unknown interface class.");
         }
 
@@ -235,17 +288,24 @@ public static void addSerialVersionUID(String className, long serialVersionUID)
      */
     private void addCodebase(String codebase, String className)
     {
-        if( codebase == null )
+        if (codebase == null)
+        {
             return;
+        }
 
-        if( className.startsWith("java.") || className.startsWith("[Ljava") || className.startsWith("javax.") )
+        if (className.startsWith("java.") || className.startsWith("[Ljava") || className.startsWith("javax."))
+        {
             codebases.putIfAbsent(codebase, new HashSet<String>());
+        }
 
-        else if( codebases.containsKey(codebase) ) {
+        else if (codebases.containsKey(codebase))
+        {
             Set<String> classNames = codebases.get(codebase);
             classNames.add(className);
+        }
 
-        } else {
+        else
+        {
             Set<String> classNames = new HashSet<String>();
             classNames.add(className);
             codebases.put(codebase, classNames);

src/eu/tneitzel/rmg/networking/RMIRegistryEndpoint.java

@@ -219,7 +219,7 @@ public Remote lookup(String boundName) throws UnmarshalException
                 ExceptionHandler.notBoundException(e, boundName);
             }
 
-            catch( Exception e )
+            catch (Exception e)
             {
                 Throwable cause = ExceptionHandler.getCause(e);
 

src/eu/tneitzel/rmg/plugin/PluginSystem.java

@@ -34,6 +34,7 @@
 public class PluginSystem
 {
     private static String manifestAttribute = "RmgPluginClass";
+    public static URLClassLoader pluginLoader = null;
 
     private static IActionProvider actionProvider = null;
     private static IPayloadProvider payloadProvider = null;
@@ -115,8 +116,8 @@ private static void loadPlugin(String pluginPath)
 
         try
         {
-            URLClassLoader ucl = new URLClassLoader(new URL[] {pluginFile.toURI().toURL()});
-            Class<?> pluginClass = Class.forName(pluginClassName, true, ucl);
+            pluginLoader = new URLClassLoader(new URL[] {pluginFile.toURI().toURL()});
+            Class<?> pluginClass = Class.forName(pluginClassName, true, pluginLoader);
             pluginInstance = pluginClass.newInstance();
         }