com.dragome.methodlogger.serverside.MethodLoggerBytecodeTransformer.java Source code

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Here is the source code for com.dragome.methodlogger.serverside.MethodLoggerBytecodeTransformer.java

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/*
 * Copyright (c) 2011-2014 Fernando Petrola
 *
 * 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.dragome.methodlogger.serverside;

import java.util.Set;

import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.tree.ClassNode;

import com.dragome.commons.compiler.BytecodeTransformer;

public class MethodLoggerBytecodeTransformer implements BytecodeTransformer {
    protected Set<String> includePathsList;
    private boolean enabled;

    public MethodLoggerBytecodeTransformer(Set<String> includePathsList, boolean enabled) {
        this.includePathsList = includePathsList;
        this.enabled = enabled;
    }

    public boolean requiresTransformation(String className) {
        if (!enabled)
            return false;

        for (String path : includePathsList)
            if (className.startsWith(path))
                return true;

        return false;
    }

    public byte[] transform(String className, byte[] bytecode) {
        if (requiresTransformation(className)) {
            ClassNode classNode = new ClassNode(Opcodes.ASM5);
            MethodLoggerAdapter invokeDynamicConverter = new MethodLoggerAdapter(classNode);
            new ClassReader(bytecode).accept(invokeDynamicConverter, ClassReader.EXPAND_FRAMES);
            ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS);
            classNode.accept(cw);
            return cw.toByteArray();
        } else
            return bytecode;
    }
}