    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    package org.apache.commons.compress.archivers.ar;
    020
    021    import java.io.File;
    022    import java.util.Date;
    023
    024    import org.apache.commons.compress.archivers.ArchiveEntry;
    025
    026    /**
    027     * Represents an archive entry in the "ar" format.
    028     *
    029     * Each AR archive starts with "!<arch>" followed by a LF. After these 8 bytes
    030     * the archive entries are listed. The format of an entry header is as it follows:
    031     *
    032     * <pre>
    033     * START BYTE   END BYTE    NAME                    FORMAT      LENGTH
    034     * 0            15          File name               ASCII       16
    035     * 16           27          Modification timestamp  Decimal     12
    036     * 28           33          Owner ID                Decimal     6
    037     * 34           39          Group ID                Decimal     6
    038     * 40           47          File mode               Octal       8
    039     * 48           57          File size (bytes)       Decimal     10
    040     * 58           59          File magic              \140\012    2
    041     * </pre>
    042     *
    043     * This specifies that an ar archive entry header contains 60 bytes.
    044     *
    045     * Due to the limitation of the file name length to 16 bytes GNU and BSD has
    046     * their own variants of this format. This formats are currently not supported
    047     * and file names with a bigger size than 16 bytes are not possible at the
    048     * moment.
    049     *
    050     * @Immutable
    051     */
    052    public class ArArchiveEntry implements ArchiveEntry {
    053
    054        /** The header for each entry */
    055        public static final String HEADER = "!<arch>\n";
    056
    057        /** The trailer for each entry */
    058        public static final String TRAILER = "`\012";
    059
    060        /**
    061         * SVR4/GNU adds a trailing / to names; BSD does not.
    062         * They also vary in how names longer than 16 characters are represented.
    063         * (Not yet supported by this implementation)
    064         */
    065        private final String name;
    066        private final int userId;
    067        private final int groupId;
    068        private final int mode;
    069        private static final int DEFAULT_MODE = 33188; // = (octal) 0100644
    070        private final long lastModified;
    071        private final long length;
    072
    073        /**
    074         * Create a new instance using a couple of default values.
    075         *
    076         * <p>Sets userId and groupId to 0, the octal file mode to 644 and
    077         * the last modified time to the current time.</p>
    078         *
    079         * @param name name of the entry
    080         * @param length length of the entry in bytes
    081         */
    082        public ArArchiveEntry(String name, long length) {
    083            this(name, length, 0, 0, DEFAULT_MODE,
    084                 System.currentTimeMillis() / 1000);
    085        }
    086
    087        /**
    088         * Create a new instance.
    089         *
    090         * @param name name of the entry
    091         * @param length length of the entry in bytes
    092         * @param userId numeric user id
    093         * @param groupId numeric group id
    094         * @param mode file mode
    095         * @param lastModified last modified time in seconds since the epoch
    096         */
    097        public ArArchiveEntry(String name, long length, int userId, int groupId,
    098                              int mode, long lastModified) {
    099            this.name = name;
    100            this.length = length;
    101            this.userId = userId;
    102            this.groupId = groupId;
    103            this.mode = mode;
    104            this.lastModified = lastModified;
    105        }
    106
    107        /**
    108         * Create a new instance using the attributes of the given file
    109         */
    110        public ArArchiveEntry(File inputFile, String entryName) {
    111            // TODO sort out mode
    112            this(entryName, inputFile.isFile() ? inputFile.length() : 0,
    113                 0, 0, DEFAULT_MODE, inputFile.lastModified() / 1000);
    114        }
    115
    116        /** {@inheritDoc} */
    117        public long getSize() {
    118            return this.getLength();
    119        }
    120
    121        /** {@inheritDoc} */
    122        public String getName() {
    123            return name;
    124        }
    125
    126        public int getUserId() {
    127            return userId;
    128        }
    129
    130        public int getGroupId() {
    131            return groupId;
    132        }
    133
    134        public int getMode() {
    135            return mode;
    136        }
    137
    138        /**
    139         * Last modified time in seconds since the epoch.
    140         */
    141        public long getLastModified() {
    142            return lastModified;
    143        }
    144
    145        /** {@inheritDoc} */
    146        public Date getLastModifiedDate() {
    147            return new Date(1000 * getLastModified());
    148        }
    149
    150        public long getLength() {
    151            return length;
    152        }
    153
    154        /** {@inheritDoc} */
    155        public boolean isDirectory() {
    156            return false;
    157        }
    158
    159        /** {@inheritDoc} */
    160        public int hashCode() {
    161            final int prime = 31;
    162            int result = 1;
    163            result = prime * result + ((name == null) ? 0 : name.hashCode());
    164            return result;
    165        }
    166
    167        /** {@inheritDoc} */
    168        public boolean equals(Object obj) {
    169            if (this == obj) {
    170                return true;
    171            }
    172            if (obj == null || getClass() != obj.getClass()) {
    173                return false;
    174            }
    175            ArArchiveEntry other = (ArArchiveEntry) obj;
    176            if (name == null) {
    177                if (other.name != null) {
    178                    return false;
    179                }
    180            } else if (!name.equals(other.name)) {
    181                return false;
    182            }
    183            return true;
    184        }
    185    }