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 */ 018package org.apache.commons.compress.archivers.zip; 019 020import static org.apache.commons.compress.archivers.zip.ZipConstants.BYTE_MASK; 021 022import java.io.Serializable; 023import java.math.BigInteger; 024 025/** 026 * Utility class that represents an eight byte integer with conversion 027 * rules for the little endian byte order of ZIP files. 028 * @Immutable 029 * 030 * @since 1.2 031 */ 032public final class ZipEightByteInteger implements Serializable { 033 private static final long serialVersionUID = 1L; 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 static final int BYTE_4 = 4; 048 private static final long BYTE_4_MASK = 0xFF00000000L; 049 private static final int BYTE_4_SHIFT = 32; 050 051 private static final int BYTE_5 = 5; 052 private static final long BYTE_5_MASK = 0xFF0000000000L; 053 private static final int BYTE_5_SHIFT = 40; 054 055 private static final int BYTE_6 = 6; 056 private static final long BYTE_6_MASK = 0xFF000000000000L; 057 private static final int BYTE_6_SHIFT = 48; 058 059 private static final int BYTE_7 = 7; 060 private static final long BYTE_7_MASK = 0x7F00000000000000L; 061 private static final int BYTE_7_SHIFT = 56; 062 063 private static final int LEFTMOST_BIT_SHIFT = 63; 064 private static final byte LEFTMOST_BIT = (byte) 0x80; 065 066 public static final ZipEightByteInteger ZERO = new ZipEightByteInteger(0); 067 068 /** 069 * Get value as eight bytes in big endian byte order. 070 * @param value the value to convert 071 * @return value as eight bytes in big endian byte order 072 */ 073 public static byte[] getBytes(final BigInteger value) { 074 final byte[] result = new byte[8]; 075 final long val = value.longValue(); 076 result[0] = (byte) ((val & BYTE_MASK)); 077 result[BYTE_1] = (byte) ((val & BYTE_1_MASK) >> BYTE_1_SHIFT); 078 result[BYTE_2] = (byte) ((val & BYTE_2_MASK) >> BYTE_2_SHIFT); 079 result[BYTE_3] = (byte) ((val & BYTE_3_MASK) >> BYTE_3_SHIFT); 080 result[BYTE_4] = (byte) ((val & BYTE_4_MASK) >> BYTE_4_SHIFT); 081 result[BYTE_5] = (byte) ((val & BYTE_5_MASK) >> BYTE_5_SHIFT); 082 result[BYTE_6] = (byte) ((val & BYTE_6_MASK) >> BYTE_6_SHIFT); 083 result[BYTE_7] = (byte) ((val & BYTE_7_MASK) >> BYTE_7_SHIFT); 084 if (value.testBit(LEFTMOST_BIT_SHIFT)) { 085 result[BYTE_7] |= LEFTMOST_BIT; 086 } 087 return result; 088 } 089 090 /** 091 * Get value as eight bytes in big endian byte order. 092 * @param value the value to convert 093 * @return value as eight bytes in big endian byte order 094 */ 095 public static byte[] getBytes(final long value) { 096 return getBytes(BigInteger.valueOf(value)); 097 } 098 099 /** 100 * Helper method to get the value as a Java long from an eight-byte array 101 * @param bytes the array of bytes 102 * @return the corresponding Java long value 103 */ 104 public static long getLongValue(final byte[] bytes) { 105 return getLongValue(bytes, 0); 106 } 107 108 /** 109 * Helper method to get the value as a Java long from eight bytes 110 * starting at given array offset 111 * @param bytes the array of bytes 112 * @param offset the offset to start 113 * @return the corresponding Java long value 114 */ 115 public static long getLongValue(final byte[] bytes, final int offset) { 116 return getValue(bytes, offset).longValue(); 117 } 118 119 /** 120 * Helper method to get the value as a Java long from an eight-byte array 121 * @param bytes the array of bytes 122 * @return the corresponding Java BigInteger value 123 */ 124 public static BigInteger getValue(final byte[] bytes) { 125 return getValue(bytes, 0); 126 } 127 128 /** 129 * Helper method to get the value as a Java BigInteger from eight 130 * bytes starting at given array offset 131 * @param bytes the array of bytes 132 * @param offset the offset to start 133 * @return the corresponding Java BigInteger value 134 */ 135 public static BigInteger getValue(final byte[] bytes, final int offset) { 136 long value = ((long) bytes[offset + BYTE_7] << BYTE_7_SHIFT) & BYTE_7_MASK; 137 value += ((long) bytes[offset + BYTE_6] << BYTE_6_SHIFT) & BYTE_6_MASK; 138 value += ((long) bytes[offset + BYTE_5] << BYTE_5_SHIFT) & BYTE_5_MASK; 139 value += ((long) bytes[offset + BYTE_4] << BYTE_4_SHIFT) & BYTE_4_MASK; 140 value += ((long) bytes[offset + BYTE_3] << BYTE_3_SHIFT) & BYTE_3_MASK; 141 value += ((long) bytes[offset + BYTE_2] << BYTE_2_SHIFT) & BYTE_2_MASK; 142 value += ((long) bytes[offset + BYTE_1] << BYTE_1_SHIFT) & BYTE_1_MASK; 143 value += ((long) bytes[offset] & BYTE_MASK); 144 final BigInteger val = BigInteger.valueOf(value); 145 return (bytes[offset + BYTE_7] & LEFTMOST_BIT) == LEFTMOST_BIT 146 ? val.setBit(LEFTMOST_BIT_SHIFT) : val; 147 } 148 149 private final BigInteger value; 150 151 /** 152 * Create instance from a number. 153 * @param value the BigInteger to store as a ZipEightByteInteger 154 */ 155 public ZipEightByteInteger(final BigInteger value) { 156 this.value = value; 157 } 158 159 /** 160 * Create instance from bytes. 161 * @param bytes the bytes to store as a ZipEightByteInteger 162 */ 163 public ZipEightByteInteger (final byte[] bytes) { 164 this(bytes, 0); 165 } 166 167 /** 168 * Create instance from the eight bytes starting at offset. 169 * @param bytes the bytes to store as a ZipEightByteInteger 170 * @param offset the offset to start 171 */ 172 public ZipEightByteInteger (final byte[] bytes, final int offset) { 173 value = ZipEightByteInteger.getValue(bytes, offset); 174 } 175 176 /** 177 * Create instance from a number. 178 * @param value the long to store as a ZipEightByteInteger 179 */ 180 public ZipEightByteInteger(final long value) { 181 this(BigInteger.valueOf(value)); 182 } 183 184 /** 185 * Override to make two instances with same value equal. 186 * @param o an object to compare 187 * @return true if the objects are equal 188 */ 189 @Override 190 public boolean equals(final Object o) { 191 if (!(o instanceof ZipEightByteInteger)) { 192 return false; 193 } 194 return value.equals(((ZipEightByteInteger) o).getValue()); 195 } 196 197 /** 198 * Get value as eight bytes in big endian byte order. 199 * @return value as eight bytes in big endian order 200 */ 201 public byte[] getBytes() { 202 return ZipEightByteInteger.getBytes(value); 203 } 204 205 /** 206 * Get value as Java long. 207 * @return value as a long 208 */ 209 public long getLongValue() { 210 return value.longValue(); 211 } 212 213 /** 214 * Get value as Java BigInteger. 215 * @return value as a BigInteger 216 */ 217 public BigInteger getValue() { 218 return value; 219 } 220 221 /** 222 * Override to make two instances with same value equal. 223 * @return the hash code of the value stored in the ZipEightByteInteger 224 */ 225 @Override 226 public int hashCode() { 227 return value.hashCode(); 228 } 229 230 @Override 231 public String toString() { 232 return "ZipEightByteInteger value: " + value; 233 } 234}