/* * Copyright (C) 2003, 2004 Robert Lougher <rob@lougher.demon.co.uk>. * * This file is part of JamVM. * * 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 2, * 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, write to the Free Software * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */package jamvm.java.lang;import java.util.jar.JarFile;import java.util.jar.Manifest;import java.util.jar.Attributes;import java.util.jar.Attributes.Name;import java.lang.reflect.Method;public class JarLauncher {    public static void main(String[] args) {        String jarFile = System.getProperty("java.class.path", null);        try {            JarFile jar = new JarFile(jarFile);            Manifest manifest = jar.getManifest();            if(manifest == null)                System.err.println("Couldn't read manifest from " + jar.getName() + " (invalid jar file?).");            else {                String mainAttr = manifest.getMainAttributes().getValue(Name.MAIN_CLASS);                if(mainAttr == null)                    System.err.println("Couldn't find Main-Class attribute in " +                                        jar.getName() + " Manifest.");                else {                    ClassLoader sysLoader = ClassLoader.getSystemClassLoader();                    Class mainClass = Class.forName(mainAttr, true, sysLoader);                    Method meth = mainClass.getMethod("main", new Class[] {args.getClass()});                    meth.invoke(null, new Object[] {args});                }            }        } catch(Exception e) {            e.printStackTrace();        }    }}