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Groovy: A powerful, dynamic language for the JVM
/*
* Copyright 2003-2007 the original author or authors.
*
* 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 org.codehaus.groovy.reflection;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.ClassReader;
import java.util.Map;
import java.util.HashMap;
import java.io.IOException;
import java.io.InputStream;
import java.security.AccessController;
import java.security.PrivilegedAction;
/**
* Special class loader, which when running on Sun VM allows to generate accessor classes for any method
*/
public class SunClassLoader extends ClassLoader implements Opcodes {
protected final Map knownClasses = new HashMap();
protected static final SunClassLoader sunVM;
static {
SunClassLoader res;
try {
res = AccessController.doPrivileged(new PrivilegedAction() {
public SunClassLoader run() {
try {
return new SunClassLoader();
} catch (Throwable e) {
return null;
}
}
});
}
catch (Throwable e) {
res = null;
}
sunVM = res;
}
protected SunClassLoader() throws Throwable {
super (SunClassLoader.class.getClassLoader());
final Class magic = ClassLoader.getSystemClassLoader().loadClass("sun.reflect.MagicAccessorImpl");
knownClasses.put("sun.reflect.MagicAccessorImpl", magic);
loadMagic ();
}
private void loadMagic() {
ClassWriter cw = new ClassWriter(true);
cw.visit(Opcodes.V1_4, Opcodes.ACC_PUBLIC, "sun/reflect/GroovyMagic", null, "sun/reflect/MagicAccessorImpl", null);
MethodVisitor mv = cw.visitMethod(Opcodes.ACC_PUBLIC, "", "()V", null, null);
mv.visitCode();
mv.visitVarInsn(ALOAD, 0);
mv.visitMethodInsn(INVOKESPECIAL, "sun/reflect/MagicAccessorImpl", "", "()V");
mv.visitInsn(RETURN);
mv.visitMaxs(0,0);
mv.visitEnd();
cw.visitEnd();
define(cw.toByteArray(), "sun.reflect.GroovyMagic");
}
protected void loadFromRes(String name) throws IOException {
final InputStream asStream = SunClassLoader.class.getClassLoader().getResourceAsStream(resName(name));
ClassReader reader = new ClassReader(asStream);
final ClassWriter cw = new ClassWriter(true);
reader.accept(cw, true);
asStream.close();
define(cw.toByteArray(), name);
}
protected static String resName(String s) {
return s.replace('.','/') + ".class";
}
protected void define(byte[] bytes, final String name) {
knownClasses.put(name, defineClass(name, bytes, 0, bytes.length));
}
protected synchronized Class loadClass(String name, boolean resolve) throws ClassNotFoundException {
final Class aClass = knownClasses.get(name);
if (aClass != null)
return aClass;
else {
try {
return super.loadClass(name, resolve);
}
catch (ClassNotFoundException e) {
return getClass().getClassLoader().loadClass(name);
}
}
}
public Class doesKnow(String name) {
return knownClasses.get(name);
}
}