/*

 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

import java.io.FileNotFoundException;

import java.io.InputStream;

import java.io.ByteArrayInputStream;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.nio.file.StandardCopyOption;

/**

 * Dump a class file for a class on the class path in the current directory

 */

public class ClassFileInstaller {

    /**

     * @param args The names of the classes to dump

     * @throws Exception

     */

    public static void main(String... args) throws Exception {

        for (String arg : args) {

            writeClassToDisk(arg);

        }

    }

    public static void writeClassToDisk(String className) throws Exception {

        writeClassToDisk(className, "");

    }

    public static void writeClassToDisk(String className, String prependPath) throws Exception {

        ClassLoader cl = ClassFileInstaller.class.getClassLoader();

        // Convert dotted class name to a path to a class file

        String pathName = className.replace('.', '/').concat(".class");

        InputStream is = cl.getResourceAsStream(pathName);

        if (prependPath.length() > 0) {

            pathName = prependPath + "/" + pathName;

        }

        writeToDisk(pathName, is);

    }

    public static void writeClassToDisk(String className, byte[] bytecode) throws Exception {

        writeClassToDisk(className, bytecode, "");

    }

    public static void writeClassToDisk(String className, byte[] bytecode, String prependPath) throws Exception {

        // Convert dotted class name to a path to a class file

        String pathName = className.replace('.', '/').concat(".class");

        if (prependPath.length() > 0) {

            pathName = prependPath + "/" + pathName;

        }

        writeToDisk(pathName, new ByteArrayInputStream(bytecode));

    }

    private static void writeToDisk(String pathName, InputStream is) throws Exception {

        // Create the class file's package directory

        Path p = Paths.get(pathName);

        if (pathName.contains("/")) {

            Files.createDirectories(p.getParent());

        }

        // Create the class file

        Files.copy(is, p, StandardCopyOption.REPLACE_EXISTING);

    }

}