com.test.api.checker.tests.ASMHelloWorld.java Source code

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Here is the source code for com.test.api.checker.tests.ASMHelloWorld.java

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/*
 * Copyright 2015 Intershop Communications AG.
 *
 * 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 com.test.api.checker.tests;

import org.objectweb.asm.*;

import java.io.IOException;
import java.io.InputStream;

public class ASMHelloWorld {

    /**
     * @param args
     * @throws IOException
     */
    public static void main(String[] args) throws IOException {
        ClassVisitor cl = new ClassVisitor(Opcodes.ASM4) {

            /**
             * Called when a class is visited. This is the method called first
             */
            @Override
            public void visit(int version, int access, String name, String signature, String superName,
                    String[] interfaces) {
                System.out.println("Visiting class: " + name);
                System.out.println("Class Major Version: " + version);
                System.out.println("Super class: " + superName);
                super.visit(version, access, name, signature, superName, interfaces);
            }

            /**
             * Invoked only when the class being visited is an inner class
             */
            @Override
            public void visitOuterClass(String owner, String name, String desc) {
                System.out.println("Outer class: " + owner);
                super.visitOuterClass(owner, name, desc);
            }

            /**
             *Invoked when a class level annotation is encountered
             */
            @Override
            public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
                System.out.println("Annotation: " + desc);
                return super.visitAnnotation(desc, visible);
            }

            /**
             * When a class attribute is encountered
             */
            @Override
            public void visitAttribute(Attribute attr) {
                System.out.println("Class Attribute: " + attr.type);
                super.visitAttribute(attr);
            }

            /**
             *When an inner class is encountered
             */
            @Override
            public void visitInnerClass(String name, String outerName, String innerName, int access) {
                System.out.println("Inner Class: " + innerName + " defined in " + outerName);
                super.visitInnerClass(name, outerName, innerName, access);
            }

            /**
             * When a field is encountered
             */
            @Override
            public FieldVisitor visitField(int access, String name, String desc, String signature, Object value) {
                System.out.println("Field: " + name + " " + desc + " value:" + value);
                return super.visitField(access, name, desc, signature, value);
            }

            @Override
            public void visitEnd() {
                System.out.println("Method ends here");
                super.visitEnd();
            }

            /**
             * When a method is encountered
             */
            @Override
            public MethodVisitor visitMethod(int access, String name, String desc, String signature,
                    String[] exceptions) {
                System.out.println("Method: " + name + " " + desc);
                return super.visitMethod(access, name, desc, signature, exceptions);
            }

            /**
             * When the optional source is encountered
             */
            @Override
            public void visitSource(String source, String debug) {
                System.out.println("Source: " + source);
                super.visitSource(source, debug);
            }

        };
        InputStream in = ASMHelloWorld.class.getResourceAsStream("/java/lang/String.class");
        ClassReader classReader = new ClassReader(in);
        classReader.accept(cl, 0);

    }

}