scouter.agent.DirectPatch.java Source code

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Here is the source code for scouter.agent.DirectPatch.java

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/*
 *  Copyright 2015 the original author or authors. 
 *  @https://github.com/scouter-project/scouter
 *
 *  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 scouter.agent;

import java.io.File;

import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.Opcodes;
import scouter.util.FileUtil;
import scouter.util.StringKeyLinkedMap;
import scouter.util.StringUtil;

public class DirectPatch {

    static StringKeyLinkedMap<byte[]> classPatchMap = new StringKeyLinkedMap<byte[]>();

    static {
        try {
            String patch = Configure.getInstance()._hook_direct_patch_classes;
            String[] files = StringUtil.tokenizer(patch, ",;");
            for (int i = 0; files != null && i < files.length; i++) {
                byte[] bytes = FileUtil.readAll(new File(files[i]));
                if (bytes != null) {
                    String classname = getClassName(bytes);
                    if (classname != null) {
                        classPatchMap.put(classname, bytes);
                    }
                }
            }
        } catch (Throwable t) {
            t.printStackTrace();
        }
    }

    private static String getClassName(byte[] bytes) {
        try {
            final ClassDesc classDesc = new ClassDesc();
            ClassReader cr = new ClassReader(bytes);
            cr.accept(new ClassVisitor(Opcodes.ASM7) {
                public void visit(int version, int access, String name, String signature, String superName,
                        String[] interfaces) {
                    classDesc.set(version, access, name, signature, superName, interfaces);
                }
            }, 0);
            return classDesc.name.replace('.', '/');
        } catch (Throwable t) {
            return null;
        }
    }

    public static byte[] patch(String name, byte[] org) {
        byte[] patchClass = classPatchMap.get(name);
        return patchClass != null ? patchClass : org;
    }
}