package org.apache.cassandra.triggers; /* * * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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. * */ import java.io.File; import java.io.FilenameFilter; import java.io.IOError; import java.io.IOException; import java.net.URL; import java.net.URLClassLoader; import java.util.Map; import java.util.concurrent.ConcurrentHashMap; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.google.common.io.Files; /** * Custom class loader will load the classes from the class path, CCL will load * the classes from the the URL first, if it cannot find the required class it * will let the parent class loader do the its job. * * Note: If the CCL is GC'ed then the associated classes will be unloaded. */ public class CustomClassLoader extends URLClassLoader { private static final Logger logger = LoggerFactory.getLogger(CustomClassLoader.class); private final Map<String, Class<?>> cache = new ConcurrentHashMap<String, Class<?>>(); private final ClassLoader parent; public CustomClassLoader(ClassLoader parent) { super(new URL[] {}, parent); assert parent != null; this.parent = getParent(); } public CustomClassLoader(ClassLoader parent, File classPathDir) { super(new URL[] {}, parent); assert parent != null; this.parent = getParent(); addClassPath(classPathDir); } public void addClassPath(File dir) { if (dir == null || !dir.exists()) return; FilenameFilter filter = new FilenameFilter() { public boolean accept(File dir, String name) { return name.endsWith(".jar"); } }; for (File inputJar : dir.listFiles(filter)) { File lib = new File(System.getProperty("java.io.tmpdir"), "lib"); if (!lib.exists()) { lib.mkdir(); lib.deleteOnExit(); } try { File out = File.createTempFile("cassandra-", ".jar", lib); out.deleteOnExit(); logger.info("Loading new jar {}", inputJar.getAbsolutePath()); Files.copy(inputJar, out); addURL(out.toURI().toURL()); } catch (IOException ex) { throw new IOError(ex); } } } @Override public Class<?> loadClass(String name) throws ClassNotFoundException { Class<?> clazz = cache.get(name); if (clazz == null) return loadClassInternal(name); return clazz; } public synchronized Class<?> loadClassInternal(String name) throws ClassNotFoundException { try { return parent.loadClass(name); } catch (ClassNotFoundException ex) { logger.debug("Class not found using parent class loader,", ex); // Don't throw the exception here, try triggers directory. } Class<?> clazz = this.findClass(name); cache.put(name, clazz); return clazz; } }