me.rgcjonas.portableMinecraftLauncher.Main.java Source code

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Here is the source code for me.rgcjonas.portableMinecraftLauncher.Main.java

Source

/*
 *   PortableMinecraftLauncher
 *   Copyright (C) 2012 Jonas Kuemmerlin <rgcjonas@gmail.com>
 *
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   This program 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 for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package me.rgcjonas.portableMinecraftLauncher;

import java.io.File;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URL;
import java.net.URLDecoder;
import org.apache.commons.io.FileUtils;

/**
 * 'God Object'
 * manages program flow and computes our working directory.
 * @author Jonas Kuemmerlin <rgcjonas@gmail.com>
 *
 */
public class Main {

    /**
     * entry point
     * @param args
     */
    public static void main(String[] args) {
        File workDir = getWorkingDirectory();

        //ensure the working directory exists
        if (!workDir.exists()) {
            workDir.mkdir();
        }
        File launcherJar = new File(workDir, "launcher.jar");

        //download launcher if it doesn't exist
        if (!launcherJar.exists()) {
            try {
                URL launcherurl = new URL("https://s3.amazonaws.com/MinecraftDownload/launcher/minecraft.jar");
                FileUtils.copyURLToFile(launcherurl, launcherJar);
            } catch (IOException e) {
                // shouldn't happen
                e.printStackTrace();
            }
        }

        URL[] urls;
        try {
            urls = new URL[] { launcherJar.toURI().toURL() };

            //this class loader mustn't be disposed while the launcher is running
            @SuppressWarnings("resource")
            LauncherClassLoader loader = new LauncherClassLoader(urls);

            //run it      
            Class<?> launcherFrame = loader.loadClass("net.minecraft.LauncherFrame");
            launcherFrame.getMethod("main", String[].class).invoke(null, (Object) args);
        } catch (Exception e) {
            // there's nothing we can do in that case but notify the dev
            e.printStackTrace();
        }
    }

    /**
     * returns the working directory for the portable minecraft instance
     */
    public static File getWorkingDirectory() {
        String path = Main.class.getProtectionDomain().getCodeSource().getLocation().getPath();
        String decodedPath = null;
        try {
            decodedPath = URLDecoder.decode(path, "UTF-8");
        } catch (UnsupportedEncodingException e) {
            //this is very unlikely to happen, we're just making eclipse happy
            e.printStackTrace();
        }

        File ourDir = null;
        if (decodedPath.endsWith(".jar")) {
            //inside a jar file -> new dir named like the jar file
            ourDir = new File(decodedPath.substring(0, decodedPath.length() - 4));
        } else {
            //subdir 'minecraft'
            ourDir = new File(decodedPath, "minecraft");
        }

        //HACK: make it absolute here, since the other code requires
        File workDir = new File(ourDir.getAbsolutePath());
        return workDir;
    }

}