Implement delete plugin

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

@@ -257,6 +257,7 @@ public class DefaultPluginManager implements PluginManager {
         // expand all plugin archives
         FileFilter zipFilter = new ZipFileFilter();
         File[] zipFiles = pluginsDirectory.listFiles(zipFilter);
+        if (zipFiles != null) {
         	for (File zipFile : zipFiles) {
         		try {
         			expandPluginArchive(zipFile);
@@ -264,6 +265,7 @@ public class DefaultPluginManager implements PluginManager {
         			log.error(e.getMessage(), e);
         		}
         	}
+        }
 
         // check for no plugins
         List<FileFilter> filterList = new ArrayList<FileFilter>();
@@ -271,14 +273,18 @@ public class DefaultPluginManager implements PluginManager {
         filterList.add(new NotFileFilter(createHiddenPluginFilter()));
         FileFilter pluginsFilter = new AndFileFilter(filterList);
         File[] directories = pluginsDirectory.listFiles(pluginsFilter);
-        log.debug("Found possible {} plugins: {}", directories.length, Arrays.asList(directories));
+        List<File> dirArray = new ArrayList<File>();
-        if (directories.length == 0) {
+        if (directories != null) {
+        	dirArray.addAll(Arrays.asList(directories));
+        }
+        log.debug("Found possible {} plugins: {}", dirArray.size(), dirArray);
+        if (dirArray.size() == 0) {
         	log.info("No plugins");
         	return;
         }
 
         // load any plugin from plugins directory
-        for (File directory : directories) {
+       	for (File directory : dirArray) {
        		try {
        			loadPlugin(directory);
        		} catch (PluginException e) {
@@ -333,6 +339,51 @@ public class DefaultPluginManager implements PluginManager {
     	return false;
     }
 
+    @Override
+	public boolean deletePlugin(String pluginId) {
+    	if (!plugins.containsKey(pluginId)) {
+    		throw new IllegalArgumentException(String.format("Unknown pluginId %s", pluginId));
+    	}
+		PluginWrapper pw = getPlugin(pluginId);
+		PluginState state = stopPlugin(pluginId);
+
+		if (PluginState.STOPPED != state) {
+			log.error(String.format("Failed to stop plugin %s on delete", pluginId));
+			return false;
+		}
+
+		if (!unloadPlugin(pluginId)) {
+			log.error(String.format("Failed to unload plugin %s on delete", pluginId));
+			return false;
+		}
+
+		File pluginFolder = new File(pluginsDirectory, pw.getPluginPath());
+		File pluginZip = null;
+
+		FileFilter zipFilter = new ZipFileFilter();
+        File[] zipFiles = pluginsDirectory.listFiles(zipFilter);
+        if (zipFiles != null) {
+        	// strip prepended / from the plugin path
+        	String dirName = pw.getPluginPath().substring(1);
+        	// find the zip file that matches the plugin path
+        	for (File zipFile : zipFiles) {
+        		String name = zipFile.getName().substring(0, zipFile.getName().lastIndexOf('.'));
+        		if (name.equals(dirName)) {
+        			pluginZip = zipFile;
+        			break;
+        		}
+        	}
+        }
+
+		if (pluginFolder.exists()) {
+			FileUtils.delete(pluginFolder);
+		}
+		if (pluginZip != null && pluginZip.exists()) {
+			FileUtils.delete(pluginZip);
+		}
+		return true;
+	}
+
     /**
      * Get plugin class loader for this path.
      */

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

@@ -79,6 +79,14 @@ public interface PluginManager {
      */
     public boolean unloadPlugin(String pluginId);
 
+    /**
+     * Deletes a plugin.
+     *
+     * @param pluginId
+     * @return true if the plugin was deleted
+     */
+    public boolean deletePlugin(String pluginId);
+
 	public PluginClassLoader getPluginClassLoader(String pluginId);
 
 	public <T> List<T> getExtensions(Class<T> type);

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

@@ -50,4 +50,27 @@ public class FileUtils {
 		return lines;
 	}
 
+	/**
+	 * Delete a file or recursively delete a folder.
+	 *
+	 * @param fileOrFolder
+	 * @return true, if successful
+	 */
+	public static boolean delete(File fileOrFolder) {
+		boolean success = false;
+		if (fileOrFolder.isDirectory()) {
+			File [] files = fileOrFolder.listFiles();
+			if (files != null) {
+				for (File file : files) {
+					if (file.isDirectory()) {
+						success |= delete(file);
+					} else {
+						success |= file.delete();
+					}
+				}
+			}
+		}
+		success |= fileOrFolder.delete();
+		return success;
+	}
 }