| /* |
| * Copyright 2004 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| * CA 95054 USA or visit www.sun.com if you need additional information or |
| * have any questions. |
| */ |
| |
| import java.io.*; |
| import java.nio.*; |
| import java.nio.channels.*; |
| |
| |
| public class CheckClassFileVersion { |
| |
| static String get(String fn) throws IOException { |
| ByteBuffer bb = ByteBuffer.allocate(1024); |
| FileChannel fc = new FileInputStream(fn).getChannel(); |
| try { |
| bb.clear(); |
| if (fc.read(bb) < 0) |
| throw new IOException("Could not read any bytes"); |
| bb.flip(); |
| int minor = bb.getShort(4); |
| int major = bb.getShort(6); |
| return major + "." + minor; |
| } finally { |
| fc.close(); |
| } |
| } |
| |
| public static void main(String[] args) throws IOException { |
| String cfv = get(args[0]); |
| if (args.length == 1) { |
| System.out.println(cfv); |
| return; |
| } |
| if (!cfv.equals(args[1])) { |
| System.err.println("Class-file version mismatch: Expected " |
| + args[1] + ", got " + cfv); |
| System.exit(1); |
| } |
| } |
| |
| } |