Implementation of a simple plugin system and a FileSearch class

src/zutil/plugin/PluginData.java

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+/*******************************************************************************
+ * Copyright (c) 2014 Ziver
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ ******************************************************************************/
+
+package zutil.plugin;
+
+import zutil.parser.DataNode;
+
+/**
+ * This class contains information about a plugin
+ * and implementation instances of the plugin interfaces
+ *  
+ * @author Ziver
+ */
+public class PluginData<T> {
+	private double pluginVersion;
+	private String pluginName;	
+	private String pluginClass;
+	
+	private T obj;
+	
+	
+	protected PluginData(String intf, DataNode data){		
+		pluginVersion = data.getDouble("version");
+		pluginName = data.getString("name");		
+		pluginClass = data.get("interfaces").getString(intf);
+	}
+	
+	public double getVersion(){
+		return pluginVersion;
+	}
+	public String getName(){
+		return pluginName;
+	}
+	
+	@SuppressWarnings("unchecked")
+	public T getObject() throws InstantiationException, IllegalAccessException, ClassNotFoundException{
+		if(obj == null)
+			obj = (T) Class.forName(pluginClass).newInstance();
+		return obj;
+	}
+
+}

src/zutil/plugin/PluginManager.java

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+/*******************************************************************************
+ * Copyright (c) 2014 Ziver
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ ******************************************************************************/
+
+package zutil.plugin;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Iterator;
+
+import zutil.io.file.FileSearch;
+import zutil.io.file.FileUtil;
+import zutil.parser.DataNode;
+import zutil.parser.json.JSONParser;
+
+/**
+ * This class will search the file system for files
+ * with the name "plugin.json" that defines data 
+ * parameters for a single plugin.
+ * The class will only load the latest version of the specific plugin.
+ * 
+ * @author Ziver
+ */
+public class PluginManager<T> implements Iterable<PluginData<T>>{
+	private HashMap<String, PluginData<T>> plugins;
+	
+	public static <T> PluginManager<T> load(Class<T> intfClass) throws IOException{
+		return new PluginManager<T>(intfClass);
+	}
+
+	
+	private PluginManager(Class<T> intfClass) throws IOException{
+		FileSearch search = new FileSearch(new File("."));
+		search.setRecursive(true);
+		search.searchFolders(false);
+		search.setFileName("plugin.json");
+		
+		for(File file : search){
+			DataNode node = JSONParser.read(FileUtil.getFileContent(file));
+			PluginData<T> plugin = new PluginData<T>(intfClass.getName(), node);
+			
+			if(node.get("interfaces").getString(intfClass.getName()) != null){
+				if(plugins.containsKey(plugin.getName())){
+					if(plugins.get(plugin.getName()).getVersion() < plugin.getVersion())
+						plugins.put(plugin.getName(), plugin);
+				}
+				else{
+					plugins.put(plugin.getName(), plugin);
+				}
+			}
+		}
+	}
+	
+	@Override
+	public Iterator<PluginData<T>> iterator() {
+		return plugins.values().iterator();
+	}
+	
+}

src/zutil/plugin/plugin.json.example

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+{
+	version = 1.0,
+	name = "Nice name of Plugin"
+	interfaces = {
+		"plugin.interface.class" = "plugin.implementation.class",
+		"wa.server.plugin.WAFrontend" = "wa.server.plugin.apache.ApacheFrontend",
+	}
+}