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 */ 017package org.apache.commons.compress.archivers.zip; 018 019import static org.apache.commons.compress.archivers.zip.ZipConstants.BYTE_MASK; 020 021import java.io.Serializable; 022import java.math.BigInteger; 023 024/** 025 * Utility class that represents an eight byte integer with conversion 026 * rules for the little endian byte order of ZIP files. 027 * @Immutable 028 * 029 * @since 1.2 030 */ 031public final class ZipEightByteInteger implements Serializable { 032 private static final long serialVersionUID = 1L; 033 034 private static final int BYTE_1 = 1; 035 private static final int BYTE_1_MASK = 0xFF00; 036 private static final int BYTE_1_SHIFT = 8; 037 038 private static final int BYTE_2 = 2; 039 private static final int BYTE_2_MASK = 0xFF0000; 040 private static final int BYTE_2_SHIFT = 16; 041 042 private static final int BYTE_3 = 3; 043 private static final long BYTE_3_MASK = 0xFF000000L; 044 private static final int BYTE_3_SHIFT = 24; 045 046 private static final int BYTE_4 = 4; 047 private static final long BYTE_4_MASK = 0xFF00000000L; 048 private static final int BYTE_4_SHIFT = 32; 049 050 private static final int BYTE_5 = 5; 051 private static final long BYTE_5_MASK = 0xFF0000000000L; 052 private static final int BYTE_5_SHIFT = 40; 053 054 private static final int BYTE_6 = 6; 055 private static final long BYTE_6_MASK = 0xFF000000000000L; 056 private static final int BYTE_6_SHIFT = 48; 057 058 private static final int BYTE_7 = 7; 059 private static final long BYTE_7_MASK = 0x7F00000000000000L; 060 private static final int BYTE_7_SHIFT = 56; 061 062 private static final int LEFTMOST_BIT_SHIFT = 63; 063 private static final byte LEFTMOST_BIT = (byte) 0x80; 064 065 public static final ZipEightByteInteger ZERO = new ZipEightByteInteger(0); 066 067 /** 068 * Get value as eight bytes in big endian byte order. 069 * @param value the value to convert 070 * @return value as eight bytes in big endian byte order 071 */ 072 public static byte[] getBytes(final BigInteger value) { 073 final byte[] result = new byte[8]; 074 final long val = value.longValue(); 075 result[0] = (byte) ((val & BYTE_MASK)); 076 result[BYTE_1] = (byte) ((val & BYTE_1_MASK) >> BYTE_1_SHIFT); 077 result[BYTE_2] = (byte) ((val & BYTE_2_MASK) >> BYTE_2_SHIFT); 078 result[BYTE_3] = (byte) ((val & BYTE_3_MASK) >> BYTE_3_SHIFT); 079 result[BYTE_4] = (byte) ((val & BYTE_4_MASK) >> BYTE_4_SHIFT); 080 result[BYTE_5] = (byte) ((val & BYTE_5_MASK) >> BYTE_5_SHIFT); 081 result[BYTE_6] = (byte) ((val & BYTE_6_MASK) >> BYTE_6_SHIFT); 082 result[BYTE_7] = (byte) ((val & BYTE_7_MASK) >> BYTE_7_SHIFT); 083 if (value.testBit(LEFTMOST_BIT_SHIFT)) { 084 result[BYTE_7] |= LEFTMOST_BIT; 085 } 086 return result; 087 } 088 089 /** 090 * Get value as eight bytes in big endian byte order. 091 * @param value the value to convert 092 * @return value as eight bytes in big endian byte order 093 */ 094 public static byte[] getBytes(final long value) { 095 return getBytes(BigInteger.valueOf(value)); 096 } 097 098 /** 099 * Helper method to get the value as a Java long from an eight-byte array 100 * @param bytes the array of bytes 101 * @return the corresponding Java long value 102 */ 103 public static long getLongValue(final byte[] bytes) { 104 return getLongValue(bytes, 0); 105 } 106 107 /** 108 * Helper method to get the value as a Java long from eight bytes 109 * starting at given array offset 110 * @param bytes the array of bytes 111 * @param offset the offset to start 112 * @return the corresponding Java long value 113 */ 114 public static long getLongValue(final byte[] bytes, final int offset) { 115 return getValue(bytes, offset).longValue(); 116 } 117 118 /** 119 * Helper method to get the value as a Java long from an eight-byte array 120 * @param bytes the array of bytes 121 * @return the corresponding Java BigInteger value 122 */ 123 public static BigInteger getValue(final byte[] bytes) { 124 return getValue(bytes, 0); 125 } 126 127 /** 128 * Helper method to get the value as a Java BigInteger from eight 129 * bytes starting at given array offset 130 * @param bytes the array of bytes 131 * @param offset the offset to start 132 * @return the corresponding Java BigInteger value 133 */ 134 public static BigInteger getValue(final byte[] bytes, final int offset) { 135 long value = ((long) bytes[offset + BYTE_7] << BYTE_7_SHIFT) & BYTE_7_MASK; 136 value += ((long) bytes[offset + BYTE_6] << BYTE_6_SHIFT) & BYTE_6_MASK; 137 value += ((long) bytes[offset + BYTE_5] << BYTE_5_SHIFT) & BYTE_5_MASK; 138 value += ((long) bytes[offset + BYTE_4] << BYTE_4_SHIFT) & BYTE_4_MASK; 139 value += ((long) bytes[offset + BYTE_3] << BYTE_3_SHIFT) & BYTE_3_MASK; 140 value += ((long) bytes[offset + BYTE_2] << BYTE_2_SHIFT) & BYTE_2_MASK; 141 value += ((long) bytes[offset + BYTE_1] << BYTE_1_SHIFT) & BYTE_1_MASK; 142 value += ((long) bytes[offset] & BYTE_MASK); 143 final BigInteger val = BigInteger.valueOf(value); 144 return (bytes[offset + BYTE_7] & LEFTMOST_BIT) == LEFTMOST_BIT 145 ? val.setBit(LEFTMOST_BIT_SHIFT) : val; 146 } 147 148 private final BigInteger value; 149 150 /** 151 * Create instance from a number. 152 * @param value the BigInteger to store as a ZipEightByteInteger 153 */ 154 public ZipEightByteInteger(final BigInteger value) { 155 this.value = value; 156 } 157 158 /** 159 * Create instance from bytes. 160 * @param bytes the bytes to store as a ZipEightByteInteger 161 */ 162 public ZipEightByteInteger (final byte[] bytes) { 163 this(bytes, 0); 164 } 165 166 /** 167 * Create instance from the eight bytes starting at offset. 168 * @param bytes the bytes to store as a ZipEightByteInteger 169 * @param offset the offset to start 170 */ 171 public ZipEightByteInteger (final byte[] bytes, final int offset) { 172 value = ZipEightByteInteger.getValue(bytes, offset); 173 } 174 175 /** 176 * Create instance from a number. 177 * @param value the long to store as a ZipEightByteInteger 178 */ 179 public ZipEightByteInteger(final long value) { 180 this(BigInteger.valueOf(value)); 181 } 182 183 /** 184 * Override to make two instances with same value equal. 185 * @param o an object to compare 186 * @return true if the objects are equal 187 */ 188 @Override 189 public boolean equals(final Object o) { 190 if (!(o instanceof ZipEightByteInteger)) { 191 return false; 192 } 193 return value.equals(((ZipEightByteInteger) o).getValue()); 194 } 195 196 /** 197 * Get value as eight bytes in big endian byte order. 198 * @return value as eight bytes in big endian order 199 */ 200 public byte[] getBytes() { 201 return ZipEightByteInteger.getBytes(value); 202 } 203 204 /** 205 * Get value as Java long. 206 * @return value as a long 207 */ 208 public long getLongValue() { 209 return value.longValue(); 210 } 211 212 /** 213 * Get value as Java BigInteger. 214 * @return value as a BigInteger 215 */ 216 public BigInteger getValue() { 217 return value; 218 } 219 220 /** 221 * Override to make two instances with same value equal. 222 * @return the hash code of the value stored in the ZipEightByteInteger 223 */ 224 @Override 225 public int hashCode() { 226 return value.hashCode(); 227 } 228 229 @Override 230 public String toString() { 231 return "ZipEightByteInteger value: " + value; 232 } 233}