    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
    020    package org.apache.commons.compress.compressors.pack200;
    021
    022    import java.io.File;
    023    import java.io.FileOutputStream;
    024    import java.io.IOException;
    025    import java.io.OutputStream;
    026    import java.util.HashMap;
    027    import java.util.Map;
    028    import java.util.jar.JarFile;
    029    import java.util.jar.JarOutputStream;
    030    import java.util.jar.Pack200;
    031
    032    /**
    033     * Utility methods for Pack200.
    034     *
    035     * @ThreadSafe
    036     * @since Apache Commons Compress 1.3
    037     */
    038    public 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    }