001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019
020package org.apache.commons.compress.compressors.pack200;
021
022import java.io.File;
023import java.io.FileOutputStream;
024import java.io.IOException;
025import java.io.OutputStream;
026import java.util.HashMap;
027import java.util.Map;
028import java.util.jar.JarFile;
029import java.util.jar.JarOutputStream;
030import java.util.jar.Pack200;
031
032/**
033 * Utility methods for Pack200.
034 *
035 * @ThreadSafe
036 * @since 1.3
037 */
038public class Pack200Utils {
039    private Pack200Utils() { }
040
041    /**
042     * Normalizes a JAR archive in-place so it can be safely signed
043     * and packed.
044     *
045     * <p>As stated in <a
046     * href="http://download.oracle.com/javase/1.5.0/docs/api/java/util/jar/Pack200.Packer.html">Pack200.Packer's</a>
047     * javadocs applying a Pack200 compression to a JAR archive will
048     * in general make its sigantures invalid.  In order to prepare a
049     * JAR for signing it should be "normalized" by packing and
050     * unpacking it.  This is what this method does.</p>
051     *
052     * <p>Note this methods implicitly sets the segment length to
053     * -1.</p>
054     *
055     * @param jar the JAR archive to normalize
056     */
057    public static void normalize(File jar)
058        throws IOException {
059        normalize(jar, jar, null);
060    }
061
062    /**
063     * Normalizes a JAR archive in-place so it can be safely signed
064     * and packed.
065     *
066     * <p>As stated in <a
067     * href="http://download.oracle.com/javase/1.5.0/docs/api/java/util/jar/Pack200.Packer.html">Pack200.Packer's</a>
068     * javadocs applying a Pack200 compression to a JAR archive will
069     * in general make its sigantures invalid.  In order to prepare a
070     * JAR for signing it should be "normalized" by packing and
071     * unpacking it.  This is what this method does.</p>
072     *
073     * @param jar the JAR archive to normalize
074     * @param props properties to set for the pack operation.  This
075     * method will implicitly set the segment limit to -1.
076     */
077    public static void normalize(File jar, Map<String, String> props)
078        throws IOException {
079        normalize(jar, jar, props);
080    }
081
082    /**
083     * Normalizes a JAR archive so it can be safely signed and packed.
084     *
085     * <p>As stated in <a
086     * href="http://download.oracle.com/javase/1.5.0/docs/api/java/util/jar/Pack200.Packer.html">Pack200.Packer's</a>
087     * javadocs applying a Pack200 compression to a JAR archive will
088     * in general make its sigantures invalid.  In order to prepare a
089     * JAR for signing it should be "normalized" by packing and
090     * unpacking it.  This is what this method does.</p>
091     *
092     * <p>This method does not replace the existing archive but creates
093     * a new one.</p>
094     *
095     * <p>Note this methods implicitly sets the segment length to
096     * -1.</p>
097     *
098     * @param from the JAR archive to normalize
099     * @param to the normalized archive
100     */
101    public static void normalize(File from, File to)
102        throws IOException {
103        normalize(from, to, null);
104    }
105
106    /**
107     * Normalizes a JAR archive so it can be safely signed and packed.
108     *
109     * <p>As stated in <a
110     * href="http://download.oracle.com/javase/1.5.0/docs/api/java/util/jar/Pack200.Packer.html">Pack200.Packer's</a>
111     * javadocs applying a Pack200 compression to a JAR archive will
112     * in general make its sigantures invalid.  In order to prepare a
113     * JAR for signing it should be "normalized" by packing and
114     * unpacking it.  This is what this method does.</p>
115     *
116     * <p>This method does not replace the existing archive but creates
117     * a new one.</p>
118     *
119     * @param from the JAR archive to normalize
120     * @param to the normalized archive
121     * @param props properties to set for the pack operation.  This
122     * method will implicitly set the segment limit to -1.
123     */
124    public static void normalize(File from, File to, Map<String, String> props)
125        throws IOException {
126        if (props == null) {
127            props = new HashMap<String, String>();
128        }
129        props.put(Pack200.Packer.SEGMENT_LIMIT, "-1");
130        File f = File.createTempFile("commons-compress", "pack200normalize");
131        f.deleteOnExit();
132        try {
133            OutputStream os = new FileOutputStream(f);
134            JarFile j = null;
135            try {
136                Pack200.Packer p = Pack200.newPacker();
137                p.properties().putAll(props);
138                p.pack(j = new JarFile(from), os);
139                j = null;
140                os.close();
141                os = null;
142
143                Pack200.Unpacker u = Pack200.newUnpacker();
144                os = new JarOutputStream(new FileOutputStream(to));
145                u.unpack(f, (JarOutputStream) os);
146            } finally {
147                if (j != null) {
148                    j.close();
149                }
150                if (os != null) {
151                    os.close();
152                }
153            }
154        } finally {
155            f.delete();
156        }
157    }
158}