| /* |
| * 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. |
| */ |
| package org.apache.sling.cta.impl; |
| |
| import java.lang.instrument.ClassFileTransformer; |
| import java.security.ProtectionDomain; |
| import java.util.Set; |
| |
| import javassist.ByteArrayClassPath; |
| import javassist.ClassPool; |
| import javassist.CtClass; |
| import javassist.LoaderClassPath; |
| import javassist.bytecode.Descriptor; |
| |
| /** |
| * Support class for transformers that expose runtime information through JMX |
| * |
| * <p>All transformer implementations should extend from this base class.</p> |
| * |
| */ |
| public abstract class MBeanAwareTimeoutTransformer implements ClassFileTransformer { |
| |
| private final AgentInfo agentInfo; |
| private final Set<String> classesToTransform; |
| |
| public MBeanAwareTimeoutTransformer(AgentInfo agent, Set<String> classesToTransform) { |
| this.agentInfo = agent; |
| this.classesToTransform = classesToTransform; |
| this.agentInfo.registerTransformer(getClass()); |
| } |
| |
| @Override |
| public byte[] transform(ClassLoader loader, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) { |
| |
| try { |
| if (classesToTransform.contains(className)) { |
| Log.get().log("%s asked to transform %s", getClass().getSimpleName(), className); |
| ClassPool classPool = new ClassPool(true); |
| // in OSGi environments access is automatically permitted to all classes, even for a Java agent |
| // therefore we need to adjust the default class path |
| // 1. append all classes accessible to the specified class loader |
| classPool.appendClassPath(new LoaderClassPath(loader)); |
| // 2. insert the current definition of the class |
| classPool.insertClassPath(new ByteArrayClassPath(Descriptor.toJavaName(className), classfileBuffer)); |
| CtClass cc = classPool.get(Descriptor.toJavaName(className)); |
| classfileBuffer = doTransformClass(cc); |
| Log.get().log("Transformation of %s complete", className); |
| this.agentInfo.registerTransformedClass(className); |
| } |
| return classfileBuffer; |
| } catch (Exception e) { |
| Log.get().fatal("Transformation failed", e); |
| return null; // NOSONAR: null return is OK in case no transform is performed |
| } |
| } |
| |
| /** |
| * Transform a class that is guaranteed to exist and in scope of this agent instance |
| * |
| * @param cc the class |
| * @return the new class definition |
| * @throws Exception in case of any problems while transforming |
| */ |
| protected abstract byte[] doTransformClass(CtClass cc) throws Exception; // NOSONAR - throwing Exception is OK, we don't want custom exceptions |
| |
| } |