| /* |
| * Copyright 1999,2004 The Apache Software Foundation. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.log4j.chainsaw.receivers; |
| |
| |
| import java.io.IOException; |
| import java.io.InputStreamReader; |
| import java.io.LineNumberReader; |
| import java.net.URL; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.List; |
| |
| import org.apache.log4j.LogManager; |
| import org.apache.log4j.Logger; |
| import org.apache.log4j.chainsaw.plugins.PluginClassLoaderFactory; |
| |
| |
| /** |
| * Helper class to assisit with all the known Receivers. |
| * |
| * A local resource 'known.receivers' is read in on initialization |
| * with each line representing the FQN of the Class that is a recognised Receiver. |
| * |
| * @author Paul Smith <psmith@apache.org> |
| * |
| */ |
| public class ReceiversHelper { |
| |
| private static final ReceiversHelper instance = new ReceiversHelper(); |
| |
| private final Logger logger = LogManager.getLogger(ReceiversHelper.class); |
| private List receiverClassList = new ArrayList(); |
| /** |
| * |
| */ |
| private ReceiversHelper() { |
| |
| URL url = this.getClass().getClassLoader().getResource( |
| this.getClass().getPackage().getName().replace('.','/') + "/known.receivers"); |
| |
| LineNumberReader stream = null; |
| try { |
| |
| stream = new LineNumberReader(new InputStreamReader(url.openStream())); |
| String line; |
| // we need the special Classloader, because under Web start, optional jars might be local |
| // to this workstation |
| ClassLoader classLoader = PluginClassLoaderFactory.getInstance().getClassLoader(); |
| |
| while ((line = stream.readLine()) != null) { |
| |
| try { |
| if (line.startsWith("#") || (line.length() == 0)) { |
| continue; |
| } |
| Class receiverClass = classLoader.loadClass(line); |
| receiverClassList.add(receiverClass); |
| logger.debug("Located known Receiver class " + receiverClass.getName()); |
| } catch (ClassNotFoundException e) { |
| logger.warn("Failed to locate Receiver class:" + line); |
| } |
| catch (NoClassDefFoundError e) { |
| logger.error("Failed to locate Receiver class:" + line + ", looks like a dependent class is missing from the classpath", e); |
| } |
| } |
| } catch (Exception e) { |
| e.printStackTrace(); |
| } finally { |
| if (stream != null) { |
| try { |
| stream.close(); |
| } catch (IOException ioe) { |
| ioe.printStackTrace(); |
| } |
| } |
| } |
| } |
| |
| |
| public static ReceiversHelper getInstance() { |
| return instance; |
| } |
| |
| |
| /** |
| * Returns an unmodifiable list of Class objects which represent all the 'known' |
| * Receiver classes. |
| * @return known receiver classes |
| */ |
| public List getKnownReceiverClasses() { |
| return Collections.unmodifiableList(receiverClassList); |
| } |
| |
| |
| } |