001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 * 017 */ 018 package org.apache.commons.compress.archivers.zip; 019 020 import java.io.Serializable; 021 022 import static org.apache.commons.compress.archivers.zip.ZipConstants.BYTE_MASK; 023 import static org.apache.commons.compress.archivers.zip.ZipConstants.WORD; 024 025 /** 026 * Utility class that represents a four byte integer with conversion 027 * rules for the big endian byte order of ZIP files. 028 * @Immutable 029 */ 030 public final class ZipLong implements Cloneable, Serializable { 031 private static final long serialVersionUID = 1L; 032 033 //private static final int BYTE_BIT_SIZE = 8; 034 035 private static final int BYTE_1 = 1; 036 private static final int BYTE_1_MASK = 0xFF00; 037 private static final int BYTE_1_SHIFT = 8; 038 039 private static final int BYTE_2 = 2; 040 private static final int BYTE_2_MASK = 0xFF0000; 041 private static final int BYTE_2_SHIFT = 16; 042 043 private static final int BYTE_3 = 3; 044 private static final long BYTE_3_MASK = 0xFF000000L; 045 private static final int BYTE_3_SHIFT = 24; 046 047 private final long value; 048 049 /** Central File Header Signature */ 050 public static final ZipLong CFH_SIG = new ZipLong(0X02014B50L); 051 052 /** Local File Header Signature */ 053 public static final ZipLong LFH_SIG = new ZipLong(0X04034B50L); 054 055 /** 056 * Data Descriptor signature. 057 * 058 * <p>Actually, PKWARE uses this as marker for split/spanned 059 * archives and other archivers have started to use it as Data 060 * Descriptor signature (as well).</p> 061 * @since 1.1 062 */ 063 public static final ZipLong DD_SIG = new ZipLong(0X08074B50L); 064 065 /** 066 * Value stored in size and similar fields if ZIP64 extensions are 067 * used. 068 * @since 1.3 069 */ 070 static final ZipLong ZIP64_MAGIC = new ZipLong(ZipConstants.ZIP64_MAGIC); 071 072 /** 073 * Marks ZIP archives that were supposed to be split or spanned 074 * but only needed a single segment in then end (so are actually 075 * neither split nor spanned). 076 * 077 * <p>This is the "PK00" prefix found in some archives.</p> 078 * @since 1.5 079 */ 080 public static final ZipLong SINGLE_SEGMENT_SPLIT_MARKER = 081 new ZipLong(0X30304B50L); 082 083 /** 084 * Archive extra data record signature.</p> 085 * @since 1.5 086 */ 087 public static final ZipLong AED_SIG = new ZipLong(0X08064B50L); 088 089 /** 090 * Create instance from a number. 091 * @param value the long to store as a ZipLong 092 */ 093 public ZipLong(long value) { 094 this.value = value; 095 } 096 097 /** 098 * Create instance from bytes. 099 * @param bytes the bytes to store as a ZipLong 100 */ 101 public ZipLong (byte[] bytes) { 102 this(bytes, 0); 103 } 104 105 /** 106 * Create instance from the four bytes starting at offset. 107 * @param bytes the bytes to store as a ZipLong 108 * @param offset the offset to start 109 */ 110 public ZipLong (byte[] bytes, int offset) { 111 value = ZipLong.getValue(bytes, offset); 112 } 113 114 /** 115 * Get value as four bytes in big endian byte order. 116 * @return value as four bytes in big endian order 117 */ 118 public byte[] getBytes() { 119 return ZipLong.getBytes(value); 120 } 121 122 /** 123 * Get value as Java long. 124 * @return value as a long 125 */ 126 public long getValue() { 127 return value; 128 } 129 130 /** 131 * Get value as four bytes in big endian byte order. 132 * @param value the value to convert 133 * @return value as four bytes in big endian byte order 134 */ 135 public static byte[] getBytes(long value) { 136 byte[] result = new byte[WORD]; 137 result[0] = (byte) ((value & BYTE_MASK)); 138 result[BYTE_1] = (byte) ((value & BYTE_1_MASK) >> BYTE_1_SHIFT); 139 result[BYTE_2] = (byte) ((value & BYTE_2_MASK) >> BYTE_2_SHIFT); 140 result[BYTE_3] = (byte) ((value & BYTE_3_MASK) >> BYTE_3_SHIFT); 141 return result; 142 } 143 144 /** 145 * Helper method to get the value as a Java long from four bytes starting at given array offset 146 * @param bytes the array of bytes 147 * @param offset the offset to start 148 * @return the corresponding Java long value 149 */ 150 public static long getValue(byte[] bytes, int offset) { 151 long value = (bytes[offset + BYTE_3] << BYTE_3_SHIFT) & BYTE_3_MASK; 152 value += (bytes[offset + BYTE_2] << BYTE_2_SHIFT) & BYTE_2_MASK; 153 value += (bytes[offset + BYTE_1] << BYTE_1_SHIFT) & BYTE_1_MASK; 154 value += (bytes[offset] & BYTE_MASK); 155 return value; 156 } 157 158 /** 159 * Helper method to get the value as a Java long from a four-byte array 160 * @param bytes the array of bytes 161 * @return the corresponding Java long value 162 */ 163 public static long getValue(byte[] bytes) { 164 return getValue(bytes, 0); 165 } 166 167 /** 168 * Override to make two instances with same value equal. 169 * @param o an object to compare 170 * @return true if the objects are equal 171 */ 172 @Override 173 public boolean equals(Object o) { 174 if (o == null || !(o instanceof ZipLong)) { 175 return false; 176 } 177 return value == ((ZipLong) o).getValue(); 178 } 179 180 /** 181 * Override to make two instances with same value equal. 182 * @return the value stored in the ZipLong 183 */ 184 @Override 185 public int hashCode() { 186 return (int) value; 187 } 188 189 @Override 190 public Object clone() { 191 try { 192 return super.clone(); 193 } catch (CloneNotSupportedException cnfe) { 194 // impossible 195 throw new RuntimeException(cnfe); 196 } 197 } 198 199 @Override 200 public String toString() { 201 return "ZipLong value: " + value; 202 } 203 }