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 static org.apache.commons.compress.archivers.zip.ZipConstants.BYTE_MASK; 021 import static org.apache.commons.compress.archivers.zip.ZipConstants.WORD; 022 023 /** 024 * Utility class that represents a four byte integer with conversion 025 * rules for the big endian byte order of ZIP files. 026 * @Immutable 027 */ 028 public final class ZipLong implements Cloneable { 029 030 //private static final int BYTE_BIT_SIZE = 8; 031 032 private static final int BYTE_1 = 1; 033 private static final int BYTE_1_MASK = 0xFF00; 034 private static final int BYTE_1_SHIFT = 8; 035 036 private static final int BYTE_2 = 2; 037 private static final int BYTE_2_MASK = 0xFF0000; 038 private static final int BYTE_2_SHIFT = 16; 039 040 private static final int BYTE_3 = 3; 041 private static final long BYTE_3_MASK = 0xFF000000L; 042 private static final int BYTE_3_SHIFT = 24; 043 044 private final long value; 045 046 /** Central File Header Signature */ 047 public static final ZipLong CFH_SIG = new ZipLong(0X02014B50L); 048 049 /** Local File Header Signature */ 050 public static final ZipLong LFH_SIG = new ZipLong(0X04034B50L); 051 052 /** 053 * Data Descriptor signature 054 * @since 1.1 055 */ 056 public static final ZipLong DD_SIG = new ZipLong(0X08074B50L); 057 058 /** 059 * Value stored in size and similar fields if ZIP64 extensions are 060 * used. 061 * @since 1.3 062 */ 063 static final ZipLong ZIP64_MAGIC = new ZipLong(ZipConstants.ZIP64_MAGIC); 064 065 /** 066 * Create instance from a number. 067 * @param value the long to store as a ZipLong 068 */ 069 public ZipLong(long value) { 070 this.value = value; 071 } 072 073 /** 074 * Create instance from bytes. 075 * @param bytes the bytes to store as a ZipLong 076 */ 077 public ZipLong (byte[] bytes) { 078 this(bytes, 0); 079 } 080 081 /** 082 * Create instance from the four bytes starting at offset. 083 * @param bytes the bytes to store as a ZipLong 084 * @param offset the offset to start 085 */ 086 public ZipLong (byte[] bytes, int offset) { 087 value = ZipLong.getValue(bytes, offset); 088 } 089 090 /** 091 * Get value as four bytes in big endian byte order. 092 * @return value as four bytes in big endian order 093 */ 094 public byte[] getBytes() { 095 return ZipLong.getBytes(value); 096 } 097 098 /** 099 * Get value as Java long. 100 * @return value as a long 101 */ 102 public long getValue() { 103 return value; 104 } 105 106 /** 107 * Get value as four bytes in big endian byte order. 108 * @param value the value to convert 109 * @return value as four bytes in big endian byte order 110 */ 111 public static byte[] getBytes(long value) { 112 byte[] result = new byte[WORD]; 113 result[0] = (byte) ((value & BYTE_MASK)); 114 result[BYTE_1] = (byte) ((value & BYTE_1_MASK) >> BYTE_1_SHIFT); 115 result[BYTE_2] = (byte) ((value & BYTE_2_MASK) >> BYTE_2_SHIFT); 116 result[BYTE_3] = (byte) ((value & BYTE_3_MASK) >> BYTE_3_SHIFT); 117 return result; 118 } 119 120 /** 121 * Helper method to get the value as a Java long from four bytes starting at given array offset 122 * @param bytes the array of bytes 123 * @param offset the offset to start 124 * @return the corresponding Java long value 125 */ 126 public static long getValue(byte[] bytes, int offset) { 127 long value = (bytes[offset + BYTE_3] << BYTE_3_SHIFT) & BYTE_3_MASK; 128 value += (bytes[offset + BYTE_2] << BYTE_2_SHIFT) & BYTE_2_MASK; 129 value += (bytes[offset + BYTE_1] << BYTE_1_SHIFT) & BYTE_1_MASK; 130 value += (bytes[offset] & BYTE_MASK); 131 return value; 132 } 133 134 /** 135 * Helper method to get the value as a Java long from a four-byte array 136 * @param bytes the array of bytes 137 * @return the corresponding Java long value 138 */ 139 public static long getValue(byte[] bytes) { 140 return getValue(bytes, 0); 141 } 142 143 /** 144 * Override to make two instances with same value equal. 145 * @param o an object to compare 146 * @return true if the objects are equal 147 */ 148 @Override 149 public boolean equals(Object o) { 150 if (o == null || !(o instanceof ZipLong)) { 151 return false; 152 } 153 return value == ((ZipLong) o).getValue(); 154 } 155 156 /** 157 * Override to make two instances with same value equal. 158 * @return the value stored in the ZipLong 159 */ 160 @Override 161 public int hashCode() { 162 return (int) value; 163 } 164 165 @Override 166 public Object clone() { 167 try { 168 return super.clone(); 169 } catch (CloneNotSupportedException cnfe) { 170 // impossible 171 throw new RuntimeException(cnfe); 172 } 173 } 174 175 @Override 176 public String toString() { 177 return "ZipLong value: " + value; 178 } 179 }