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 }