org.shelloid.netverif.ClassTransformerClassLoader.java Source code

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Here is the source code for org.shelloid.netverif.ClassTransformerClassLoader.java

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/*
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package org.shelloid.netverif;

/**
 *
 * @author jayaraj
 */
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.HashSet;
import java.util.Set;

import org.apache.commons.io.IOUtils;
import org.apache.commons.javaflow.bytecode.NetVerifBytecodeClassLoader;
import org.apache.commons.javaflow.bytecode.transformation.ResourceTransformer;
import org.apache.commons.javaflow.bytecode.transformation.asm.AsmClassTransformer;
import org.objectweb.asm.ClassReader;
import org.objectweb.asm.util.ASMifier;
import org.objectweb.asm.util.CheckClassAdapter;
import org.objectweb.asm.util.TraceClassVisitor;

public final class ClassTransformerClassLoader extends NetVerifBytecodeClassLoader {

    private final ResourceTransformer transformer;

    public ClassTransformerClassLoader(ClassLoader parent) {
        super(parent);
        transformer = new AsmClassTransformer();
    }

    protected byte[] transform(final String pName, final InputStream pClassStream) throws IOException {
        final byte[] oldClass = IOUtils.toByteArray(pClassStream);
        final byte[] newClass = transformer.transform(oldClass);

        // CheckClassAdapter.verify(new ClassReader(newClass), true);

        // Test case output has been moved to target/test-instrumentation to reduce clutter in main directory
        new File("target/test-instrumentation").mkdirs();

        CheckClassAdapter.verify(new ClassReader(newClass), true,
                new PrintWriter(new FileOutputStream("target/test-instrumentation/"
                        + transformer.getClass().getSimpleName() + "_" + pName + ".new.check.bin")));

        new ClassReader(oldClass).accept(new TraceClassVisitor(null, new ASMifier(),
                new PrintWriter(new FileOutputStream("target/test-instrumentation/"
                        + transformer.getClass().getSimpleName() + "_" + pName + ".old.bin"))),
                0);

        new ClassReader(newClass).accept(new TraceClassVisitor(null, new ASMifier(),
                new PrintWriter(new FileOutputStream("target/test-instrumentation/"
                        + transformer.getClass().getSimpleName() + "_" + pName + ".new.bin"))),
                0);

        return newClass;
    }

    public Class<?> loadClass(final String name) throws ClassNotFoundException {

        final int i = name.indexOf('$');
        final String key;

        if (i == -1) {
            key = name;
        } else {
            key = name.substring(0, i);
        }

        if (name.startsWith("org.shelloid.netverif")) {

            try {
                final InputStream is = getClass().getResourceAsStream("/" + name.replace('.', '/') + ".class");

                final byte[] bytecode;

                if (true) {
                    // System.err.println("Instrumenting: " + name);
                    bytecode = transform(name, is);
                } else {
                    // System.err.println("Loading: " + name);
                    bytecode = new ClassReader(is).b;
                }

                return super.defineClass(name, bytecode, 0, bytecode.length);

            } catch (Throwable ex) {
                // System.err.println("Load error: " + ex.toString());
                ex.printStackTrace();
                throw new ClassNotFoundException(name + " " + ex.getMessage(), ex);
            }
        }

        // System.err.println("Delegating: " + name);
        return super.loadClass(name);
    }
}