a first version related to enable-disable plugin

demo/app/src/main/java/ro/fortsoft/pf4j/demo/Boot.java

@@ -34,12 +34,18 @@ public class Boot {
     	// create the plugin manager
         final PluginManager pluginManager = new DefaultPluginManager();
 
-        // load and start (active/resolved) the plugins
+        // load the plugins
         pluginManager.loadPlugins();
+
+        // enable a disabled plugin
+        pluginManager.enablePlugin("welcome-plugin");
+
+        // start (active/resolved) the plugins
         pluginManager.startPlugins();
 
         // retrieves the extensions for Greeting extension point
         List<Greeting> greetings = pluginManager.getExtensions(Greeting.class);
+        System.out.println(String.format("### Found %d extensions for the extension point '%s'", greetings.size(), Greeting.class.getName()));
         for (Greeting greeting : greetings) {
         	System.out.println(">>> " + greeting.getGreeting());
         }

demo/disabled.txt

@@ -1,6 +0,0 @@
-########################################
-# - load all plugins except these
-# - add one plugin id on each line
-# - put this file in plugins folder
-########################################
-welcome-plugin

demo/enabled.txt

@@ -1,6 +0,0 @@
-########################################
-# - load only these plugins
-# - add one plugin id on each line
-# - put this file in plugins folder
-########################################
-welcome-plugin

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

@@ -127,6 +127,18 @@ public class DefaultPluginManager implements PluginManager {
         return new ArrayList<PluginWrapper>(plugins.values());
     }
 
+    @Override
+    public List<PluginWrapper> getPlugins(PluginState pluginState) {
+        List<PluginWrapper> plugins= new ArrayList<PluginWrapper>();
+        for (PluginWrapper plugin : getPlugins()) {
+            if (pluginState.equals(plugin.getPluginState())) {
+                plugins.add(plugin);
+            }
+        }
+
+        return plugins;
+    }
+
     @Override
 	public List<PluginWrapper> getResolvedPlugins() {
 		return resolvedPlugins;
@@ -182,8 +194,10 @@ public class DefaultPluginManager implements PluginManager {
 	@Override
     public void startPlugins() {
         for (PluginWrapper pluginWrapper : resolvedPlugins) {
+            PluginDescriptor pluginDescriptor = pluginWrapper.getDescriptor();
+            if (!isPluginDisabled(pluginDescriptor.getPluginId())) {
                 try {
-            	log.info("Start plugin '{}'", pluginWrapper.getDescriptor().getPluginId());
+                    log.info("Start plugin '{}:{}'", pluginDescriptor.getPluginId(), pluginDescriptor.getVersion());
                     pluginWrapper.getPlugin().start();
                     pluginWrapper.setPluginState(PluginState.STARTED);
                     startedPlugins.add(pluginWrapper);
@@ -192,6 +206,7 @@ public class DefaultPluginManager implements PluginManager {
                 }
             }
         }
+    }
 
 	/**
      * Start the specified plugin and it's dependencies.
@@ -201,15 +216,24 @@ public class DefaultPluginManager implements PluginManager {
     	if (!plugins.containsKey(pluginId)) {
     		throw new IllegalArgumentException(String.format("Unknown pluginId %s", pluginId));
     	}
+
     	PluginWrapper pluginWrapper = plugins.get(pluginId);
     	PluginDescriptor pluginDescriptor = pluginWrapper.getDescriptor();
     	if (pluginWrapper.getPluginState().equals(PluginState.STARTED)) {
     		log.debug("Already started plugin '{}:{}'", pluginDescriptor.getPluginId(), pluginDescriptor.getVersion());
     		return PluginState.STARTED;
     	}
+
+        // test for disabled plugin
+        if (isPluginDisabled(pluginDescriptor.getPluginId())) {
+            // do nothing
+            return pluginWrapper.getPluginState();
+        }
+
         for (PluginDependency dependency : pluginDescriptor.getDependencies()) {
     		startPlugin(dependency.getPluginId());
     	}
+
     	try {
     		log.info("Start plugin '{}:{}'", pluginDescriptor.getPluginId(), pluginDescriptor.getVersion());
     		pluginWrapper.getPlugin().start();
@@ -218,6 +242,7 @@ public class DefaultPluginManager implements PluginManager {
     	} catch (PluginException e) {
     		log.error(e.getMessage(), e);
     	}
+
     	return pluginWrapper.getPluginState();
     }
 
@@ -232,6 +257,7 @@ public class DefaultPluginManager implements PluginManager {
         while (itr.hasNext()) {
         	PluginWrapper pluginWrapper = itr.next();
         	PluginDescriptor pluginDescriptor = pluginWrapper.getDescriptor();
+            if (!isPluginDisabled(pluginDescriptor.getPluginId())) {
                 try {
                     log.info("Stop plugin '{}:{}'", pluginDescriptor.getPluginId(), pluginDescriptor.getVersion());
                     pluginWrapper.getPlugin().stop();
@@ -242,6 +268,7 @@ public class DefaultPluginManager implements PluginManager {
                 }
             }
         }
+    }
 
     /**
      * Stop the specified plugin and it's dependencies.
@@ -251,15 +278,24 @@ public class DefaultPluginManager implements PluginManager {
     	if (!plugins.containsKey(pluginId)) {
     		throw new IllegalArgumentException(String.format("Unknown pluginId %s", pluginId));
     	}
+
     	PluginWrapper pluginWrapper = plugins.get(pluginId);
     	PluginDescriptor pluginDescriptor = pluginWrapper.getDescriptor();
     	if (pluginWrapper.getPluginState().equals(PluginState.STOPPED)) {
     		log.debug("Already stopped plugin '{}:{}'", pluginDescriptor.getPluginId(), pluginDescriptor.getVersion());
     		return PluginState.STOPPED;
     	}
+
+        // test for disabled plugin
+        if (isPluginDisabled(pluginDescriptor.getPluginId())) {
+            // do nothing
+            return pluginWrapper.getPluginState();
+        }
+
     	for (PluginDependency dependency : pluginDescriptor.getDependencies()) {
     		stopPlugin(dependency.getPluginId());
     	}
+
     	try {
     		log.info("Stop plugin '{}:{}'", pluginDescriptor.getPluginId(), pluginDescriptor.getVersion());
     		pluginWrapper.getPlugin().stop();
@@ -268,6 +304,7 @@ public class DefaultPluginManager implements PluginManager {
     	} catch (PluginException e) {
     		log.error(e.getMessage(), e);
     	}
+
     	return pluginWrapper.getPluginState();
     }
 
@@ -365,6 +402,43 @@ public class DefaultPluginManager implements PluginManager {
     	} catch (IllegalArgumentException e) {
     		// ignore not found exceptions because this method is recursive
     	}
+
+    	return false;
+    }
+
+    @Override
+    public boolean disablePlugin(String pluginId) {
+        if (plugins.containsKey(pluginId)) {
+            log.debug("Unloading plugin {}", pluginId);
+            unloadPlugin(pluginId);
+        }
+
+        if (disabledPlugins.add(pluginId)) {
+            try {
+                FileUtils.writeLines(disabledPlugins, new File(pluginsDirectory, "disabled.txt"));
+                return true;
+            } catch (IOException e) {
+                log.error("Failed to disable plugin {}", pluginId, e);
+            }
+        }
+
+        return false;
+    }
+
+    @Override
+    public boolean enablePlugin(String pluginId) {
+        if (!disabledPlugins.remove(pluginId)) {
+            log.debug("Plugin {} was not disabled", pluginId);
+            return true;
+        }
+
+        try {
+            FileUtils.writeLines(disabledPlugins, new File(pluginsDirectory, "disabled.txt"));
+            return true;
+        } catch (IOException e) {
+            log.error("Failed to enable plugin {}", pluginId, e);
+        }
+
         return false;
     }
 
@@ -495,7 +569,8 @@ public class DefaultPluginManager implements PluginManager {
     	return new PluginClasspath();
     }
 
-    protected boolean isPluginDisabled(String pluginId) {
+    @Override
+    public boolean isPluginDisabled(String pluginId) {
     	if (enabledPlugins.isEmpty()) {
     		return disabledPlugins.contains(pluginId);
     	}
@@ -575,12 +650,6 @@ public class DefaultPluginManager implements PluginManager {
         String pluginClassName = pluginDescriptor.getPluginClass();
         log.debug("Class '{}' for plugin '{}'",  pluginClassName, pluginPath);
 
-        // test for disabled plugin
-        if (isPluginDisabled(pluginDescriptor.getPluginId())) {
-        	log.info("Plugin '{}' is disabled", pluginPath);
-            return null;
-        }
-
         // load plugin
         log.debug("Loading plugin '{}'", pluginPath);
         PluginLoader pluginLoader = new PluginLoader(this, pluginDescriptor, pluginDirectory, pluginClasspath);
@@ -591,6 +660,13 @@ public class DefaultPluginManager implements PluginManager {
         log.debug("Creating wrapper for plugin '{}'", pluginPath);
         PluginWrapper pluginWrapper = new PluginWrapper(pluginDescriptor, pluginPath, pluginLoader.getPluginClassLoader());
         pluginWrapper.setRuntimeMode(getRuntimeMode());
+        /*
+        // test for disabled plugin
+        if (isPluginDisabled(pluginDescriptor.getPluginId())) {
+            log.info("Plugin '{}' is disabled", pluginPath);
+            pluginWrapper.setPluginState(PluginState.DISABLED);
+        }
+        */
         log.debug("Created wrapper '{}' for plugin '{}'", pluginWrapper, pluginPath);
 
         String pluginId = pluginDescriptor.getPluginId();

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

@@ -12,8 +12,11 @@
  */
 package ro.fortsoft.pf4j;
 
+import java.io.IOException;
 import java.net.URL;
 import java.net.URLClassLoader;
+import java.util.Collections;
+import java.util.Enumeration;
 import java.util.List;
 
 /**
@@ -91,4 +94,21 @@ public class PluginClassLoader extends URLClassLoader {
         return super.loadClass(className);
     }
 
+    @Override
+    public URL getResource(String name) {
+        if (pluginManager.isPluginDisabled(pluginDescriptor.getPluginId())) {
+            return null;
+        }
+
+        return super.getResource(name);
+    }
+
+    @Override
+    public Enumeration<URL> getResources(String name) throws IOException {
+        if (pluginManager.isPluginDisabled(pluginDescriptor.getPluginId())) {
+            return Collections.emptyEnumeration();
+        }
+
+        return super.getResources(name);
+    }
 }

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

@@ -18,7 +18,7 @@ import java.util.List;
 /**
  * The classpath of the plugin after it was unpacked.
  * It contains classes directories and lib directories (directories that contains jars).
- * All directories are relativ to plugin repository.
+ * All directories are relative to plugin repository.
  * The default values are "classes" and "lib".
  *
  * @author Decebal Suiu

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

@@ -28,6 +28,11 @@ public interface PluginManager {
      */
     public List<PluginWrapper> getPlugins();
 
+    /**
+     * Retrieves all plugins with this state.
+     */
+    public List<PluginWrapper> getPlugins(PluginState pluginState);
+
     /**
      * Retrieves all resolved plugins (with resolved dependency).
      */
@@ -88,6 +93,24 @@ public interface PluginManager {
      */
     public boolean unloadPlugin(String pluginId);
 
+    public boolean isPluginDisabled(String pluginId);
+
+    /**
+     * Disables a plugin from being loaded.
+     *
+     * @param pluginId
+     * @return true if plugin is disabled
+     */
+    public boolean disablePlugin(String pluginId);
+
+    /**
+     * Enables a plugin that has previously been disabled.
+     *
+     * @param pluginId
+     * @return true if plugin is enabled
+     */
+    public boolean enablePlugin(String pluginId);
+
     /**
      * Deletes a plugin.
      *

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

@@ -18,11 +18,12 @@ package ro.fortsoft.pf4j;
 public class PluginState {
 
 	public static final PluginState CREATED = new PluginState("CREATED");
-	public static final PluginState INITIALIZED = new PluginState("INITIALIZED");	
+//	public static final PluginState INITIALIZED = new PluginState("INITIALIZED");
+//    public static final PluginState DISABLED = new PluginState("DISABLED");
 	public static final PluginState STARTED = new PluginState("STARTED");
 	public static final PluginState STOPPED = new PluginState("STOPPED");
-	public static final PluginState DESTROYED = new PluginState("DESTROYED");
-	public static final PluginState FAILED = new PluginState("FAILED");
+//	public static final PluginState DESTROYED = new PluginState("DESTROYED");
+//	public static final PluginState FAILED = new PluginState("FAILED");
 
 	private String status;
 
@@ -30,6 +31,23 @@ public class PluginState {
 		this.status = status;
 	}
 
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        PluginState that = (PluginState) o;
+
+        if (!status.equals(that.status)) return false;
+
+        return true;
+    }
+
+    @Override
+    public int hashCode() {
+        return status.hashCode();
+    }
+
     @Override
 	public String toString() {
 		return status;

pf4j/src/main/java/ro/fortsoft/pf4j/util/FileUtils.java

@@ -12,11 +12,9 @@
  */
 package ro.fortsoft.pf4j.util;
 
-import java.io.BufferedReader;
-import java.io.File;
-import java.io.FileReader;
-import java.io.IOException;
+import java.io.*;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 
@@ -50,6 +48,21 @@ public class FileUtils {
 		return lines;
 	}
 
+    public static void writeLines(Collection<String> lines, File file) throws IOException {
+        BufferedWriter writer = null;
+        try {
+            writer = new BufferedWriter(new FileWriter(file));
+            for (String line : lines) {
+                writer.write(line);
+                writer.write('\n');
+            }
+        } finally {
+            if (writer != null) {
+                writer.close();
+            }
+        }
+    }
+
 	/**
 	 * Delete a file or recursively delete a folder.
 	 *
@@ -71,6 +84,7 @@ public class FileUtils {
 			}
 		}
 		success |= fileOrFolder.delete();
+
 		return success;
 	}
 }