Added "class-loader-of" field to plugin.yml. Big thanks to CmdrDats for the PR.

By: Nathan Adams <dinnerbone@dinnerbone.com>

paper-api/src/main/java/org/bukkit/plugin/PluginDescriptionFile.java

@@ -19,6 +19,7 @@ public final class PluginDescriptionFile {
     private static final Yaml yaml = new Yaml(new SafeConstructor());
     private String name = null;
     private String main = null;
+    private String classLoaderOf = null;
     private ArrayList<String> depend = null;
     private ArrayList<String> softDepend = null;
     private String version = null;
@@ -154,6 +155,10 @@ public final class PluginDescriptionFile {
         return defaultPerm;
     }
 
+    public String getClassLoaderOf() {
+        return classLoaderOf;
+    }
+
     @SuppressWarnings("unchecked")
     private void loadMap(Map<String, Object> map) throws InvalidDescriptionException {
         try {
@@ -195,6 +200,10 @@ public final class PluginDescriptionFile {
             }
         }
 
+        if (map.containsKey("class-loader-of")) {
+            classLoaderOf = map.get("class-loader-of").toString();
+        }
+
         if (map.containsKey("depend")) {
             try {
                 depend = (ArrayList<String>) map.get("depend");
@@ -318,6 +327,10 @@ public final class PluginDescriptionFile {
             map.put("authors", authors);
         }
 
+        if (classLoaderOf != null) {
+            map.put("class-loader-of", classLoaderOf);
+        }
+
         return map;
     }
 }

paper-api/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java

@@ -167,7 +167,14 @@ public class JavaPluginLoader implements PluginLoader {
             URL[] urls = new URL[1];
 
             urls[0] = file.toURI().toURL();
-            loader = new PluginClassLoader(this, urls, getClass().getClassLoader());
+
+            if (description.getClassLoaderOf() != null) {
+                loader = loaders.get(description.getClassLoaderOf());
+                loader.addURL(urls[0]);
+            } else {
+                loader = new PluginClassLoader(this, urls, getClass().getClassLoader());
+            }
+
             Class<?> jarClass = Class.forName(description.getMain(), true, loader);
             Class<? extends JavaPlugin> plugin = jarClass.asSubclass(JavaPlugin.class);
 

paper-api/src/main/java/org/bukkit/plugin/java/PluginClassLoader.java

@@ -19,6 +19,11 @@ public class PluginClassLoader extends URLClassLoader {
         this.loader = loader;
     }
 
+    @Override
+    public void addURL(URL url) { // Override for access level!
+        super.addURL(url);
+    }
+
     @Override
     protected Class<?> findClass(String name) throws ClassNotFoundException {
         return findClass(name, true);