Refactored Plugin into an interface, make Javaplugin and relevant code to attempt to actually load plugins

By: Dinnerbone <dinnerbone@dinnerbone.com>

paper-api/.gitignore

@@ -0,0 +1,5 @@
+
+/build
+/nbproject
+/build.xml
+/manifest.mf

paper-api/src/org/bukkit/Server.java

@@ -1,6 +1,8 @@
 
 package org.bukkit;
 
+import org.bukkit.plugin.PluginManager;
+
 /**
  * Represents a server implementation
  */
@@ -25,4 +27,11 @@ public interface Server {
      * @return An array of Players that are currently online
      */
     public Player[] getOnlinePlayers();
+
+    /**
+     * Gets the PluginManager for interfacing with plugins
+     *
+     * @return PluginManager for this Server instance
+     */
+    public PluginManager getPluginManager();
 }

paper-api/src/org/bukkit/plugin/InvalidDescriptionException.java

@@ -5,30 +5,31 @@ package org.bukkit.plugin;
  * Thrown when attempting to load an invalid PluginDescriptionFile
  */
 public class InvalidDescriptionException extends Exception {
-    private final Exception innerException;
+    private final Throwable cause;
 
     /**
      * Constructs a new InvalidDescriptionException based on the given Exception
      *
-     * @param exception Exception that triggered this Exception
+     * @param throwable Exception that triggered this Exception
      */
-    public InvalidDescriptionException(Exception exception) {
-        innerException = exception;
+    public InvalidDescriptionException(Throwable throwable) {
+        cause = throwable;
     }
 
     /**
      * Constructs a new InvalidDescriptionException
      */
     public InvalidDescriptionException() {
-        innerException = null;
+        cause = null;
     }
 
     /**
-     * If applicable, returns the Exception that triggered this InvalidDescriptionException
+     * If applicable, returns the Exception that triggered this Exception
      *
      * @return Inner exception, or null if one does not exist
      */
-    public Exception getInnerException() {
-        return innerException;
+    @Override
+    public Throwable getCause() {
+        return cause;
     }
 }

paper-api/src/org/bukkit/plugin/InvalidPluginException.java

@@ -0,0 +1,35 @@
+
+package org.bukkit.plugin;
+
+/**
+ * Thrown when attempting to load an invalid Plugin file
+ */
+public class InvalidPluginException extends Exception {
+    private final Throwable cause;
+
+    /**
+     * Constructs a new InvalidPluginException based on the given Exception
+     *
+     * @param throwable Exception that triggered this Exception
+     */
+    public InvalidPluginException(Throwable throwable) {
+        cause = throwable;
+    }
+
+    /**
+     * Constructs a new InvalidPluginException
+     */
+    public InvalidPluginException() {
+        cause = null;
+    }
+
+    /**
+     * If applicable, returns the Exception that triggered this Exception
+     *
+     * @return Inner exception, or null if one does not exist
+     */
+    @Override
+    public Throwable getCause() {
+        return cause;
+    }
+}

paper-api/src/org/bukkit/plugin/Plugin.java

@@ -4,63 +4,49 @@ package org.bukkit.plugin;
 import org.bukkit.Server;
 
 /**
- * Represents a plugin
+ * Represents a Plugin
  */
-public abstract class Plugin {
-    private boolean isEnabled = false;
-    private final PluginLoader loader;
-    private final Server server;
-
+public interface Plugin {
     /**
-     * Constructs a new plugin instance
+     * Returns the plugin.yaml file containing the details for this plugin
      *
-     * @param pluginLoader PluginLoader that is responsible for this plugin
-     * @param instance Server instance that is running this plugin
+     * @return Contents of the plugin.yaml file
      */
-    protected Plugin(PluginLoader pluginLoader, Server instance) {
-        loader = pluginLoader;
-        server = instance;
-    }
+    public PluginDescriptionFile getDescription();
 
     /**
      * Gets the associated PluginLoader responsible for this plugin
      *
      * @return PluginLoader that controls this plugin
      */
-    protected final PluginLoader getPluginLoader() {
-        return loader;
-    }
+    public PluginLoader getPluginLoader();
 
     /**
      * Returns the Server instance currently running this plugin
      *
      * @return Server running this plugin
      */
-    public final Server getServer() {
-        return server;
-    }
+    public Server getServer();
 
     /**
      * Returns a value indicating whether or not this plugin is currently enabled
-     * 
+     *
      * @return true if this plugin is enabled, otherwise false
      */
-    public final boolean isEnabled() {
-        return isEnabled;
-    }
-
-    /**
-     * Called when this plugin is enabled
-     */
-    protected abstract void onEnable();
+    public boolean isEnabled();
 
     /**
      * Called when this plugin is disabled
      */
-    protected abstract void onDisable();
+    public void onDisable();
+
+    /**
+     * Called when this plugin is enabled
+     */
+    public void onEnable();
 
     /**
      * Called when this plugin is first initialized
      */
-    protected abstract void onInitialize();
+    public void onInitialize();
 }

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

@@ -53,6 +53,24 @@ public final class PluginDescriptionFile {
         yaml.dump(saveMap(), writer);
     }
 
+    /**
+     * Returns the name of a plugin
+     *
+     * @return String name
+     */
+    public String getName() {
+        return name;
+    }
+
+    /**
+     * Returns the main class for a plugin
+     *
+     * @return Java classpath
+     */
+    public String getMain() {
+        return main;
+    }
+
     private void loadMap(Map<String, Object> map) throws ClassCastException {
         name = (String)map.get("name");
         main = (String)map.get("main");

paper-api/src/org/bukkit/plugin/PluginLoader.java

@@ -18,6 +18,7 @@ public interface PluginLoader {
      * @return Plugin if it exists, otherwise null
      */
     public Plugin getPlugin(String name);
+    
     /**
      * Checks if the given plugin is enabled or not
      *
@@ -42,8 +43,9 @@ public interface PluginLoader {
      * @param file File to attempt to load
      * @return Plugin that was contained in the specified file, or null if
      * unsuccessful
+     * @throws InvalidPluginException Thrown when the specified file is not a plugin
      */
-    public Plugin loadPlugin(File file);
+    public Plugin loadPlugin(File file) throws InvalidPluginException;
 
     /**
      * Returns a list of all filename filters expected by this PluginLoader

paper-api/src/org/bukkit/plugin/PluginManager.java

@@ -7,6 +7,8 @@ import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Set;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 import java.util.regex.Matcher;
 import org.bukkit.Server;
 import java.util.regex.Pattern;
@@ -17,6 +19,7 @@ import java.util.regex.Pattern;
 public final class PluginManager {
     private final Server server;
     private final HashMap<Pattern, PluginLoader> fileAssociations = new HashMap<Pattern, PluginLoader>();
+    private final List<Plugin> plugins = new ArrayList<Plugin>();
 
     public PluginManager(Server instance) {
         server = instance;
@@ -63,7 +66,13 @@ public final class PluginManager {
         File[] files = directory.listFiles();
 
         for (File file : files) {
-            Plugin plugin = loadPlugin(file);
+            Plugin plugin = null;
+
+            try {
+                plugin = loadPlugin(file);
+            } catch (InvalidPluginException ex) {
+                Logger.getLogger(PluginManager.class.getName()).log(Level.SEVERE, "Could not load " + file.getPath() + " in " + directory.getPath(), ex);
+            }
             
             if (plugin != null) {
                 result.add(plugin);
@@ -80,8 +89,9 @@ public final class PluginManager {
      *
      * @param file File containing the plugin to load
      * @return The Plugin loaded, or null if it was invalid
+     * @throws InvalidPluginException Thrown when the specified file is not a valid plugin
      */
-    public Plugin loadPlugin(File file) {
+    public Plugin loadPlugin(File file) throws InvalidPluginException {
         Set<Pattern> filters = fileAssociations.keySet();
         Plugin result = null;
 
@@ -95,6 +105,11 @@ public final class PluginManager {
             }
         }
 
+        if (result != null) {
+            plugins.add(result);
+            result.onInitialize();
+        }
+
         return result;
     }
 }

paper-api/src/org/bukkit/plugin/java/JavaPlugin.java

@@ -0,0 +1,91 @@
+
+package org.bukkit.plugin.java;
+
+import java.io.File;
+import org.bukkit.Server;
+import org.bukkit.plugin.Plugin;
+import org.bukkit.plugin.PluginDescriptionFile;
+import org.bukkit.plugin.PluginLoader;
+
+/**
+ * Represents a Java plugin
+ */
+public abstract class JavaPlugin implements Plugin {
+    private boolean isEnabled = false;
+    private final PluginLoader loader;
+    private final Server server;
+    private final File file;
+    private final PluginDescriptionFile description;
+    private final ClassLoader classLoader;
+
+    /**
+     * Constructs a new Java plugin instance
+     *
+     * @param pluginLoader PluginLoader that is responsible for this plugin
+     * @param instance Server instance that is running this plugin
+     * @param desc PluginDescriptionFile containing metadata on this plugin
+     * @param plugin File containing this plugin
+     * @param cLoader ClassLoader which holds this plugin
+     */
+    protected JavaPlugin(PluginLoader pluginLoader, Server instance, PluginDescriptionFile desc, File plugin, ClassLoader cLoader) {
+        loader = pluginLoader;
+        server = instance;
+        file = plugin;
+        description = desc;
+        classLoader = cLoader;
+    }
+
+    /**
+     * Gets the associated PluginLoader responsible for this plugin
+     *
+     * @return PluginLoader that controls this plugin
+     */
+    public final PluginLoader getPluginLoader() {
+        return loader;
+    }
+
+    /**
+     * Returns the Server instance currently running this plugin
+     *
+     * @return Server running this plugin
+     */
+    public final Server getServer() {
+        return server;
+    }
+
+    /**
+     * Returns a value indicating whether or not this plugin is currently enabled
+     *
+     * @return true if this plugin is enabled, otherwise false
+     */
+    public final boolean isEnabled() {
+        return isEnabled;
+    }
+
+    /**
+     * Returns the file which contains this plugin
+     *
+     * @return File containing this plugin
+     */
+    protected File getFile() {
+        return file;
+    }
+
+    /**
+     * Returns the plugin.yaml file containing the details for this plugin
+     *
+     * @return Contents of the plugin.yaml file
+     */
+    public PluginDescriptionFile getDescription() {
+        return description;
+    }
+
+    /**
+     * Returns the ClassLoader which holds this plugin
+     *
+     * @return ClassLoader holding this plugin
+     */
+    protected ClassLoader getClassLoader() {
+        return classLoader;
+    }
+}

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

@@ -2,10 +2,19 @@
 package org.bukkit.plugin.java;
 
 import java.io.File;
+import java.io.FileNotFoundException;
+import java.lang.reflect.Constructor;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 import org.bukkit.plugin.Plugin;
 import org.bukkit.plugin.PluginLoader;
 import java.util.regex.Pattern;
 import org.bukkit.Server;
+import org.bukkit.plugin.InvalidPluginException;
+import org.bukkit.plugin.PluginDescriptionFile;
 
 /**
  * Represents a Java plugin loader, allowing plugins in the form of .jars
@@ -32,8 +41,26 @@ public final class JavaPluginLoader implements PluginLoader {
         throw new UnsupportedOperationException("Not supported yet.");
     }
 
-    public Plugin loadPlugin(File file) {
-        throw new UnsupportedOperationException("Not supported yet.");
+    public Plugin loadPlugin(File file) throws InvalidPluginException {
+        JavaPlugin result = null;
+        PluginDescriptionFile description = new PluginDescriptionFile("Sample Plugin", "org.bukkit.plugin.sample.main");
+
+        if (!file.exists()) {
+            throw new InvalidPluginException(new FileNotFoundException(String.format("%s does not exist", file.getPath())));
+        }
+
+        try {
+            ClassLoader loader = URLClassLoader.newInstance(new URL[]{file.toURI().toURL()}, getClass().getClassLoader());
+            Class<?> jarClass = Class.forName(description.getMain());
+            Class<? extends JavaPlugin> plugin = jarClass.asSubclass(JavaPlugin.class);
+            Constructor<? extends JavaPlugin> constructor = plugin.getConstructor(PluginLoader.class, Server.class, PluginDescriptionFile.class, File.class, ClassLoader.class);
+
+            result = constructor.newInstance(this, server, description, file, loader);
+        } catch (Exception ex) {
+            throw new InvalidPluginException(ex);
+        }
+
+        return (Plugin)result;
     }
 
     public Pattern[] getPluginFileFilters() {