/***
* ASM Guide
* Copyright (c) 2007 Eric Bruneton
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
package ch5.sec1;
import static org.objectweb.asm.Opcodes.ACC_INTERFACE;
import static org.objectweb.asm.Opcodes.ACC_PUBLIC;
import static org.objectweb.asm.Opcodes.ALOAD;
import static org.objectweb.asm.Opcodes.ARETURN;
import java.util.Iterator;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.tree.ClassNode;
import org.objectweb.asm.tree.MethodNode;
/**
* ASM Guide example class.
*
* @author Eric Bruneton
*/
public class AddMethodTransformer extends ClassTransformer {
public AddMethodTransformer(ClassTransformer ct) {
super(ct);
}
public void transform(ClassNode cn) {
if ((cn.access & ACC_INTERFACE) == 0) {
boolean isPresent = false;
Iterator i = cn.methods.iterator();
while (i.hasNext()) {
MethodNode mn = (MethodNode) i.next();
if ("getThis".equals(mn.name)) {
if ("()Ljava/lang/Object;".equals(mn.desc)) {
isPresent = true;
break;
}
}
}
if (!isPresent) {
MethodVisitor mv = cn.visitMethod(ACC_PUBLIC, "getThis",
"()Ljava/lang/Object;", null, null);
mv.visitCode();
mv.visitVarInsn(ALOAD, 0);
mv.visitInsn(ARETURN);
mv.visitMaxs(1, 1);
mv.visitEnd();
}
}
super.transform(cn);
}
}