Java tutorial
/* * Copyright 2009-2012 Michael Dalton * * 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 jtaint; import org.objectweb.asm.ClassAdapter; import org.objectweb.asm.ClassVisitor; import org.objectweb.asm.Opcodes; /** Instrument java.lang.Thread to store information about the current servlet * request. Allows other class to get/set this information during servlet * processing. */ public class ThreadAdapter extends ClassAdapter implements Opcodes { private String className; public ThreadAdapter(ClassVisitor cv) { super(cv); } public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) { className = name; cv.visit(version, access, name, signature, superName, interfaces); } private void addField(String fieldName, String getterName, String setterName, String desc) { String internalField = ByteCodeUtil.internalName(fieldName); cv.visitField(ACC_PRIVATE + ACC_TRANSIENT, internalField, desc, null, null).visitEnd(); ByteCodeUtil.buildGetter(cv, className, internalField, desc, ACC_FINAL, ByteCodeUtil.internalName(getterName)); ByteCodeUtil.buildSetter(cv, className, internalField, desc, ACC_FINAL, ByteCodeUtil.internalName(setterName)); } public void visitEnd() { addField("remoteAddr", "getRemoteAddr", "setRemoteAddr", "Ljava/lang/String;"); addField("remoteHost", "getRemoteHost", "setRemoteHost", "Ljava/lang/String;"); addField("requestParams", "getRequestParams", "setRequestParams", "Ljava/util/Map;"); cv.visitEnd(); } public static InstrumentationBuilder builder() { return Builder.getInstance(); } private static class Builder implements InstrumentationBuilder { private static final Builder b = new Builder(); public static InstrumentationBuilder getInstance() { return b; } public ClassVisitor build(ClassVisitor cv) { return new ThreadAdapter(cv); } } }