| /* |
| * Copyright 2009 Google Inc. |
| * |
| * 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.google.gwt.dev.shell.rewrite; |
| |
| import com.google.gwt.dev.javac.asmbridge.EmptyVisitor; |
| |
| import org.objectweb.asm.AnnotationVisitor; |
| import org.objectweb.asm.ClassReader; |
| import org.objectweb.asm.ClassVisitor; |
| import org.objectweb.asm.Opcodes; |
| import org.objectweb.asm.Type; |
| |
| import java.lang.annotation.Annotation; |
| |
| /** |
| * A simple ClassAdapter that determines if a specific annotation is declared on |
| * a type (ignoring any annotatons that may be present on supertypes or |
| * superinterfaces). |
| */ |
| public class HasAnnotation extends ClassVisitor { |
| /** |
| * A utility method to determine if the class defined in |
| * <code>classBytes</code> has a particular annotation. |
| * |
| * @param classBytes the class's bytecode |
| * @param annotation the type of annotation to look for |
| * @return <code>true</code> if the class defined in <code>classBytes</code> |
| * possesses the desired annotation |
| */ |
| public static boolean hasAnnotation(byte[] classBytes, |
| Class<? extends Annotation> annotation) { |
| HasAnnotation v = new HasAnnotation(new EmptyVisitor(), annotation); |
| new ClassReader(classBytes).accept(v, ClassReader.SKIP_CODE |
| | ClassReader.SKIP_DEBUG | ClassReader.SKIP_FRAMES); |
| |
| return v.isFound(); |
| } |
| |
| private boolean found; |
| |
| private final String targetDesc; |
| |
| public HasAnnotation(ClassVisitor v, Class<? extends Annotation> annotation) { |
| super(Opcodes.ASM6, v); |
| targetDesc = Type.getDescriptor(annotation); |
| } |
| |
| public boolean isFound() { |
| return found; |
| } |
| |
| @Override |
| public AnnotationVisitor visitAnnotation(String desc, boolean visible) { |
| if (targetDesc.equals(desc)) { |
| found = true; |
| } |
| return super.visitAnnotation(desc, visible); |
| } |
| } |