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.IOException;
024import java.io.OutputStream;
025import java.nio.file.Files;
026import java.util.HashMap;
027import java.util.Map;
028import java.util.jar.JarFile;
029import java.util.jar.JarOutputStream;
030import org.apache.commons.compress.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="https://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 signatures 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     * @throws IOException if reading or writing fails
057     */
058    public static void normalize(final File jar)
059        throws IOException {
060        normalize(jar, jar, null);
061    }
062
063    /**
064     * Normalizes a JAR archive in-place so it can be safely signed
065     * and packed.
066     *
067     * <p>As stated in <a
068     * href="https://download.oracle.com/javase/1.5.0/docs/api/java/util/jar/Pack200.Packer.html">Pack200.Packer's</a>
069     * javadocs applying a Pack200 compression to a JAR archive will
070     * in general make its signatures invalid.  In order to prepare a
071     * JAR for signing it should be "normalized" by packing and
072     * unpacking it.  This is what this method does.</p>
073     *
074     * @param jar the JAR archive to normalize
075     * @param props properties to set for the pack operation.  This
076     * method will implicitly set the segment limit to -1.
077     * @throws IOException if reading or writing fails
078     */
079    public static void normalize(final File jar, final Map<String, String> props)
080        throws IOException {
081        normalize(jar, jar, props);
082    }
083
084    /**
085     * Normalizes a JAR archive so it can be safely signed and packed.
086     *
087     * <p>As stated in <a
088     * href="https://download.oracle.com/javase/1.5.0/docs/api/java/util/jar/Pack200.Packer.html">Pack200.Packer's</a>
089     * javadocs applying a Pack200 compression to a JAR archive will
090     * in general make its signatures invalid.  In order to prepare a
091     * JAR for signing it should be "normalized" by packing and
092     * unpacking it.  This is what this method does.</p>
093     *
094     * <p>This method does not replace the existing archive but creates
095     * a new one.</p>
096     *
097     * <p>Note this methods implicitly sets the segment length to
098     * -1.</p>
099     *
100     * @param from the JAR archive to normalize
101     * @param to the normalized archive
102     * @throws IOException if reading or writing fails
103     */
104    public static void normalize(final File from, final File to)
105        throws IOException {
106        normalize(from, to, null);
107    }
108
109    /**
110     * Normalizes a JAR archive so it can be safely signed and packed.
111     *
112     * <p>As stated in <a
113     * href="https://download.oracle.com/javase/1.5.0/docs/api/java/util/jar/Pack200.Packer.html">Pack200.Packer's</a>
114     * javadocs applying a Pack200 compression to a JAR archive will
115     * in general make its signatures invalid.  In order to prepare a
116     * JAR for signing it should be "normalized" by packing and
117     * unpacking it.  This is what this method does.</p>
118     *
119     * <p>This method does not replace the existing archive but creates
120     * a new one.</p>
121     *
122     * @param from the JAR archive to normalize
123     * @param to the normalized archive
124     * @param props properties to set for the pack operation.  This
125     * method will implicitly set the segment limit to -1.
126     * @throws IOException if reading or writing fails
127     */
128    public static void normalize(final File from, final File to, Map<String, String> props)
129            throws IOException {
130        if (props == null) {
131            props = new HashMap<>();
132        }
133        props.put(Pack200.Packer.SEGMENT_LIMIT, "-1");
134        final File tempFile = File.createTempFile("commons-compress", "pack200normalize");
135        try {
136            try (OutputStream fos = Files.newOutputStream(tempFile.toPath());
137                 JarFile jarFile = new JarFile(from)) {
138                final Pack200.Packer packer = Pack200.newPacker();
139                packer.properties().putAll(props);
140                packer.pack(jarFile, fos);
141            }
142            final Pack200.Unpacker unpacker = Pack200.newUnpacker();
143            try (JarOutputStream jos = new JarOutputStream(Files.newOutputStream(to.toPath()))) {
144                unpacker.unpack(tempFile, jos);
145            }
146        } finally {
147            if (!tempFile.delete()) {
148                tempFile.deleteOnExit();
149            }
150        }
151    }
152}