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 java.util.zip.ZipException; 020 021import org.apache.commons.compress.utils.ByteUtils; 022 023/** 024 * If this extra field is added as the very first extra field of the 025 * archive, Solaris will consider it an executable jar file. 026 * @Immutable 027 */ 028public final class JarMarker implements ZipExtraField { 029 030 private static final ZipShort ID = new ZipShort(0xCAFE); 031 private static final ZipShort NULL = new ZipShort(0); 032 private static final JarMarker DEFAULT = new JarMarker(); 033 034 /** 035 * Since JarMarker is stateless we can always use the same instance. 036 * @return the DEFAULT jarmaker. 037 */ 038 public static JarMarker getInstance() { 039 return DEFAULT; 040 } 041 042 /** No-arg constructor */ 043 public JarMarker() { 044 // empty 045 } 046 047 /** 048 * The actual data to put central directory - without Header-ID or 049 * length specifier. 050 * @return the data 051 */ 052 @Override 053 public byte[] getCentralDirectoryData() { 054 return ByteUtils.EMPTY_BYTE_ARRAY; 055 } 056 057 /** 058 * Length of the extra field in the central directory - without 059 * Header-ID or length specifier. 060 * @return 0 061 */ 062 @Override 063 public ZipShort getCentralDirectoryLength() { 064 return NULL; 065 } 066 067 /** 068 * The Header-ID. 069 * @return the header id 070 */ 071 @Override 072 public ZipShort getHeaderId() { 073 return ID; 074 } 075 076 /** 077 * The actual data to put into local file data - without Header-ID 078 * or length specifier. 079 * @return the data 080 */ 081 @Override 082 public byte[] getLocalFileDataData() { 083 return ByteUtils.EMPTY_BYTE_ARRAY; 084 } 085 086 /** 087 * Length of the extra field in the local file data - without 088 * Header-ID or length specifier. 089 * @return 0 090 */ 091 @Override 092 public ZipShort getLocalFileDataLength() { 093 return NULL; 094 } 095 096 /** 097 * Doesn't do anything special since this class always uses the 098 * same data in central directory and local file data. 099 */ 100 @Override 101 public void parseFromCentralDirectoryData(final byte[] buffer, final int offset, 102 final int length) 103 throws ZipException { 104 parseFromLocalFileData(buffer, offset, length); 105 } 106 107 /** 108 * Populate data from this array as if it was in local file data. 109 * @param data an array of bytes 110 * @param offset the start offset 111 * @param length the number of bytes in the array from offset 112 * 113 * @throws ZipException on error 114 */ 115 @Override 116 public void parseFromLocalFileData(final byte[] data, final int offset, final int length) 117 throws ZipException { 118 if (length != 0) { 119 throw new ZipException("JarMarker doesn't expect any data"); 120 } 121 } 122}