1 /*
   2  * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 import java.io.IOException;
  25 import java.io.OutputStream;
  26 import java.nio.file.Files;
  27 import java.nio.file.Paths;
  28 import java.util.ArrayList;
  29 import java.util.List;
  30 import java.util.jar.Attributes;
  31 import java.util.jar.JarEntry;
  32 import java.util.jar.JarOutputStream;
  33 import java.util.jar.Manifest;
  34 
  35 public class JarBuilder {
  36     final private String name;
  37     final private Attributes attributes = new Attributes();
  38     final private List<Entry> entries = new ArrayList<>();
  39 
  40     public JarBuilder(String name) {
  41         this.name = name;
  42         attributes.putValue("Manifest-Version", "1.0");
  43         attributes.putValue("Created-By", "1.9.0-internal (Oracle Corporation)");
  44     }
  45 
  46     public JarBuilder addAttribute(String name, String value) {
  47         attributes.putValue(name, value);
  48         return this;
  49     }
  50 
  51     public JarBuilder addEntry(String name, byte[] bytes) {
  52         entries.add(new Entry(name, bytes));
  53         return this;
  54     }
  55 
  56     public void build() throws IOException {
  57         try (OutputStream os = Files.newOutputStream(Paths.get(name));
  58              JarOutputStream jos = new JarOutputStream(os)) {
  59             JarEntry me = new JarEntry("META-INF/MANIFEST.MF");
  60             jos.putNextEntry(me);
  61             Manifest manifest = new Manifest();
  62             manifest.getMainAttributes().putAll(attributes);
  63             manifest.write(jos);
  64             jos.closeEntry();
  65             entries.forEach(e -> {
  66                 JarEntry je = new JarEntry(e.name);
  67                 try {
  68                     jos.putNextEntry(je);
  69                     jos.write(e.bytes);
  70                     jos.closeEntry();
  71                 } catch (IOException iox) {
  72                     throw new RuntimeException(iox);
  73                 }
  74             });
  75         } catch (RuntimeException x) {
  76             Throwable t = x.getCause();
  77             if (t instanceof IOException) {
  78                 IOException iox = (IOException)t;
  79                 throw iox;
  80             }
  81             throw x;
  82         }
  83     }
  84 
  85     private static class Entry {
  86         String name;
  87         byte[] bytes;
  88 
  89         Entry(String name, byte[] bytes) {
  90             this.name = name;
  91             this.bytes = bytes;
  92         }
  93     }
  94 
  95     public static void main(String[] args) throws IOException {
  96         JarBuilder jb = new JarBuilder("version.jar");
  97         jb.addAttribute("Multi-Release", "true");
  98         String s = "something to say";
  99         byte[] bytes = s.getBytes();
 100         jb.addEntry("version/Version.class", bytes);
 101         jb.addEntry("README", bytes);
 102         jb.addEntry("version/Version.java", bytes);
 103         jb.build();
 104     }
 105 }