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.util.zip.ZipException; 021 022 /** 023 * If this extra field is added as the very first extra field of the 024 * archive, Solaris will consider it an executable jar file. 025 * @Immutable 026 */ 027 public final class JarMarker implements ZipExtraField { 028 029 private static final ZipShort ID = new ZipShort(0xCAFE); 030 private static final ZipShort NULL = new ZipShort(0); 031 private static final byte[] NO_BYTES = new byte[0]; 032 private static final JarMarker DEFAULT = new JarMarker(); 033 034 /** No-arg constructor */ 035 public JarMarker() { 036 // empty 037 } 038 039 /** 040 * Since JarMarker is stateless we can always use the same instance. 041 * @return the DEFAULT jarmaker. 042 */ 043 public static JarMarker getInstance() { 044 return DEFAULT; 045 } 046 047 /** 048 * The Header-ID. 049 * @return the header id 050 */ 051 public ZipShort getHeaderId() { 052 return ID; 053 } 054 055 /** 056 * Length of the extra field in the local file data - without 057 * Header-ID or length specifier. 058 * @return 0 059 */ 060 public ZipShort getLocalFileDataLength() { 061 return NULL; 062 } 063 064 /** 065 * Length of the extra field in the central directory - without 066 * Header-ID or length specifier. 067 * @return 0 068 */ 069 public ZipShort getCentralDirectoryLength() { 070 return NULL; 071 } 072 073 /** 074 * The actual data to put into local file data - without Header-ID 075 * or length specifier. 076 * @return the data 077 */ 078 public byte[] getLocalFileDataData() { 079 return NO_BYTES; 080 } 081 082 /** 083 * The actual data to put central directory - without Header-ID or 084 * length specifier. 085 * @return the data 086 */ 087 public byte[] getCentralDirectoryData() { 088 return NO_BYTES; 089 } 090 091 /** 092 * Populate data from this array as if it was in local file data. 093 * @param data an array of bytes 094 * @param offset the start offset 095 * @param length the number of bytes in the array from offset 096 * 097 * @throws ZipException on error 098 */ 099 public void parseFromLocalFileData(byte[] data, int offset, int length) 100 throws ZipException { 101 if (length != 0) { 102 throw new ZipException("JarMarker doesn't expect any data"); 103 } 104 } 105 106 /** 107 * Doesn't do anything special since this class always uses the 108 * same data in central directory and local file data. 109 */ 110 public void parseFromCentralDirectoryData(byte[] buffer, int offset, 111 int length) 112 throws ZipException { 113 parseFromLocalFileData(buffer, offset, length); 114 } 115 }