com.blade.kit.AsmKit Maven / Gradle / Ivy
/**
* Copyright (c) 2016, biezhi 王爵 ([email protected])
*
* 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.blade.kit;
import org.objectweb.asm.*;
import java.io.IOException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
/**
* ASM Tools
*
* @author biezhi
* @since 1.6.6
*/
public final class AsmKit {
/**
*
* 比较参数类型是否一致
*
*
* @param types asm的类型({@link Type})
* @param clazzes java 类型({@link Class})
* @return
*/
private static boolean sameType(Type[] types, Class[] clazzes) {
// 个数不同
if (types.length != clazzes.length) {
return false;
}
for (int i = 0; i < types.length; i++) {
if (!Type.getType(clazzes[i]).equals(types[i])) {
return false;
}
}
return true;
}
/**
*
*
* 获取方法的参数名
*
*
* @param m
* @return
*/
public static String[] getMethodParamNames(final Method m) throws IOException {
final String[] paramNames = new String[m.getParameterTypes().length];
final String n = m.getDeclaringClass().getName();
ClassReader cr = null;
try {
cr = new ClassReader(n);
} catch (IOException e) {
return null;
}
cr.accept(new ClassVisitor(Opcodes.ASM5) {
@Override
public MethodVisitor visitMethod(final int access, final String name, final String desc,
final String signature, final String[] exceptions) {
final Type[] args = Type.getArgumentTypes(desc);
// 方法名相同并且参数个数相同
if (!name.equals(m.getName()) || !sameType(args, m.getParameterTypes())) {
return super.visitMethod(access, name, desc, signature, exceptions);
}
MethodVisitor v = super.visitMethod(access, name, desc, signature, exceptions);
return new MethodVisitor(Opcodes.ASM5, v) {
@Override
public void visitLocalVariable(String name, String desc, String signature, Label start, Label end,
int index) {
int i = index - 1;
// 如果是静态方法，则第一就是参数
// 如果不是静态方法，则第一个是"this"，然后才是方法的参数
if (Modifier.isStatic(m.getModifiers())) {
i = index;
}
if (i >= 0 && i < paramNames.length) {
paramNames[i] = name;
}
super.visitLocalVariable(name, desc, signature, start, end, index);
}
};
}
}, 0);
return paramNames;
}
}