New ClassLoader to allow for inter-plugin communication

2 files changed, 55 insertions, 1 deletions

diff --git a/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java b/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java
index 1a5b9210..5ec11716 100644
--- a/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java
+++ b/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java
@@ -8,6 +8,8 @@ import java.io.InputStream;
 import java.lang.reflect.Constructor;
 import java.net.URL;
 import java.net.URLClassLoader;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.jar.JarEntry;
 import java.util.jar.JarFile;
 import java.util.regex.Pattern;
@@ -37,6 +39,7 @@ public final class JavaPluginLoader implements PluginLoader {
     private final Pattern[] fileFilters = new Pattern[] {
             Pattern.compile("\\.jar$"),
     };
+    private final Map<String, Class<?>> classes = new HashMap<String, Class<?>>();
 
     public JavaPluginLoader(Server instance) {
         server = instance;
@@ -67,7 +70,7 @@ public final class JavaPluginLoader implements PluginLoader {
         }
 
         try {
-            ClassLoader loader = URLClassLoader.newInstance(new URL[]{file.toURI().toURL()}, getClass().getClassLoader());
+            ClassLoader loader = new PluginClassLoader(this, new URL[]{file.toURI().toURL()}, getClass().getClassLoader());
             Class<?> jarClass = Class.forName(description.getMain(), true, loader);
             Class<? extends JavaPlugin> plugin = jarClass.asSubclass(JavaPlugin.class);
             Constructor<? extends JavaPlugin> constructor = plugin.getConstructor(PluginLoader.class, Server.class, PluginDescriptionFile.class, File.class, ClassLoader.class);
@@ -84,6 +87,14 @@ public final class JavaPluginLoader implements PluginLoader {
         return fileFilters;
     }
 
+    public Class<?> getClassByName(final String name) {
+        return classes.get(name);
+    }
+
+    public void setClass(final String name, final Class<?> clazz) {
+        classes.put(name, clazz);
+    }
+
     public void callEvent(RegisteredListener registration, Event event) {
         Listener listener = registration.getListener();
 
diff --git a/src/main/java/org/bukkit/plugin/java/PluginClassLoader.java b/src/main/java/org/bukkit/plugin/java/PluginClassLoader.java
new file mode 100644
index 00000000..987d5e68
--- /dev/null
+++ b/src/main/java/org/bukkit/plugin/java/PluginClassLoader.java
@@ -0,0 +1,43 @@
+
+package org.bukkit.plugin.java;
+
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.security.AccessController;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * A ClassLoader for plugins, to allow shared classes across multiple plugins
+ */
+public class PluginClassLoader extends URLClassLoader {
+    private final JavaPluginLoader loader;
+    private final Map<String, Class<?>> classes = new HashMap<String, Class<?>>();
+
+    public PluginClassLoader(final JavaPluginLoader loader, final URL[] urls, final ClassLoader parent) {
+        super(urls, parent);
+
+        this.loader = loader;
+    }
+
+    @Override
+    protected Class<?> findClass(String name) throws ClassNotFoundException {
+        Class<?> result = classes.get(name);
+
+        if (result == null) {
+            result = loader.getClassByName(name);
+
+            if (result == null) {
+                result = super.findClass(name);
+
+                if (result != null) {
+                    loader.setClass(name, result);
+                }
+            }
+
+            classes.put(name, result);
+        }
+
+        return result;
+    }
+}