/***
* 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.
*/
import static org.objectweb.asm.Opcodes.ACC_INTERFACE;
import static org.objectweb.asm.Opcodes.ACC_PUBLIC;
import static org.objectweb.asm.Opcodes.ACC_STATIC;
import static org.objectweb.asm.Opcodes.ATHROW;
import static org.objectweb.asm.Opcodes.GETSTATIC;
import static org.objectweb.asm.Opcodes.INVOKESTATIC;
import static org.objectweb.asm.Opcodes.IRETURN;
import static org.objectweb.asm.Opcodes.LADD;
import static org.objectweb.asm.Opcodes.LSUB;
import static org.objectweb.asm.Opcodes.PUTSTATIC;
import static org.objectweb.asm.Opcodes.RETURN;
import org.objectweb.asm.ClassAdapter;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.FieldVisitor;
import org.objectweb.asm.MethodAdapter;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.tree.ClassNode;
import org.objectweb.asm.util.CheckClassAdapter;
import org.objectweb.asm.util.TraceMethodVisitor;
import static org.objectweb.asm.Opcodes.ACC_PUBLIC;
import static org.objectweb.asm.Opcodes.ALOAD;
import static org.objectweb.asm.Opcodes.INVOKESPECIAL;
import static org.objectweb.asm.Opcodes.INVOKESTATIC;
import static org.objectweb.asm.Opcodes.RETURN;
import static org.objectweb.asm.Opcodes.V1_1;
/**
* ASM Guide example class.
*
* @author Eric Bruneton
*/
public class AddTimerAdapter extends ClassAdapter {
private String owner;
private boolean isInterface;
public AddTimerAdapter(ClassVisitor cv) {
super(cv);
}
public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
cv.visit(version, access, name, signature, superName, interfaces);
owner = name;
isInterface = (access & ACC_INTERFACE) != 0;
}
public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) {
MethodVisitor mv = cv.visitMethod(access, name, desc, signature, exceptions);
if (!isInterface && mv != null && !name.equals("<init>")) {
mv = new AddTimerMethodAdapter(mv);
}
return mv;
}
public void visitEnd() {
if (!isInterface) {
FieldVisitor fv = cv.visitField(ACC_PUBLIC + ACC_STATIC, "timer", "J", null, null);
if (fv != null) {
fv.visitEnd();
}
}
cv.visitEnd();
}
class AddTimerMethodAdapter extends MethodAdapter {
public AddTimerMethodAdapter(MethodVisitor mv) {
super(mv);
}
public void visitCode() {
mv.visitCode();
mv.visitFieldInsn(GETSTATIC, owner, "timer", "J");
mv.visitMethodInsn(INVOKESTATIC, "java/lang/System", "currentTimeMillis", "()J");
mv.visitInsn(LSUB);
mv.visitFieldInsn(PUTSTATIC, owner, "timer", "J");
}
public void visitInsn(int opcode) {
if ((opcode >= IRETURN && opcode <= RETURN) || opcode == ATHROW) {
mv.visitFieldInsn(GETSTATIC, owner, "timer", "J");
mv.visitMethodInsn(INVOKESTATIC, "java/lang/System", "currentTimeMillis", "()J");
mv.visitInsn(LADD);
mv.visitFieldInsn(PUTSTATIC, owner, "timer", "J");
}
mv.visitInsn(opcode);
}
public void visitMaxs(int maxStack, int maxLocals) {
mv.visitMaxs(maxStack + 4, maxLocals);
}
}
// *******************************************************
private TestClassLoader LOADER = new TestClassLoader();
private static String getText(TraceMethodVisitor mv) {
StringBuffer sb = new StringBuffer();
for (int i = 0; i < mv.text.size(); i++) {
sb.append(mv.text.get(i));
}
return sb.toString();
}
protected void generateBasicClass(ClassVisitor cv) {
FieldVisitor fv;
MethodVisitor mv;
cv.visit(V1_1, ACC_PUBLIC, "C", null, "java/lang/Object", null);
cv.visitSource("C.java", null);
fv = cv.visitField(ACC_PUBLIC, "f", "I", null, null);
if (fv != null) {
fv.visitEnd();
}
mv = cv.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
if (mv != null) {
mv.visitCode();
mv.visitVarInsn(ALOAD, 0);
mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V");
mv.visitInsn(RETURN);
mv.visitMaxs(1, 1);
mv.visitEnd();
}
mv = cv.visitMethod(ACC_PUBLIC, "m", "()V", null, null);
if (mv != null) {
mv.visitCode();
mv.visitLdcInsn(new Long(100));
mv.visitMethodInsn(INVOKESTATIC, "java/lang/Thread", "sleep", "(J)V");
mv.visitInsn(RETURN);
mv.visitMaxs(3, 1);
mv.visitEnd();
}
cv.visitEnd();
}
protected ClassNode generateBasicClass() {
ClassNode cn = new ClassNode();
generateBasicClass(cn);
return cn;
}
protected Class defineClass(String name, byte[] b) {
return LOADER.defineClass(name, b);
}
static class TestClassLoader extends ClassLoader {
public Class defineClass(String name, byte[] b) {
return defineClass(name, b, 0, b.length);
}
}
protected ClassVisitor getClassAdapter(ClassVisitor cv) {
return new AddTimerAdapter(cv);
}
//*******************************************************
public static final void main(final String[] args) throws Exception {
System.out.println("Running");
ClassWriter cw = new ClassWriter(0);
CheckClassAdapter ca = new CheckClassAdapter(cw);
AddTimerAdapter test = new AddTimerAdapter(null);
ClassVisitor cv = test.getClassAdapter(ca);
test.generateBasicClass(cv);
//************
Class c = test.defineClass("C", cw.toByteArray());
Object o = c.newInstance();
// java.lang.reflect.Field;
// java.lang.reflect.Method;
final java.lang.reflect.Method m = c.getMethod("m");
m.invoke(o);
java.lang.reflect.Field f = c.getField("timer");
System.out.println("Result: " + f.getLong(null));
}
}