001/* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 */ 019package org.apache.commons.compress.archivers.jar; 020 021import java.io.IOException; 022import java.io.InputStream; 023 024import org.apache.commons.compress.archivers.ArchiveEntry; 025import org.apache.commons.compress.archivers.zip.ZipArchiveEntry; 026import org.apache.commons.compress.archivers.zip.ZipArchiveInputStream; 027 028/** 029 * Implements an input stream that can read entries from jar files. 030 * 031 * @NotThreadSafe 032 */ 033public class JarArchiveInputStream extends ZipArchiveInputStream { 034 035 /** 036 * Creates an instance from the input stream using the default encoding. 037 * 038 * @param inputStream the input stream to wrap 039 */ 040 public JarArchiveInputStream( final InputStream inputStream ) { 041 super(inputStream); 042 } 043 044 /** 045 * Creates an instance from the input stream using the specified encoding. 046 * 047 * @param inputStream the input stream to wrap 048 * @param encoding the encoding to use 049 * @since 1.10 050 */ 051 public JarArchiveInputStream( final InputStream inputStream, final String encoding ) { 052 super(inputStream, encoding); 053 } 054 055 public JarArchiveEntry getNextJarEntry() throws IOException { 056 final ZipArchiveEntry entry = getNextZipEntry(); 057 return entry == null ? null : new JarArchiveEntry(entry); 058 } 059 060 @Override 061 public ArchiveEntry getNextEntry() throws IOException { 062 return getNextJarEntry(); 063 } 064 065 /** 066 * Checks if the signature matches what is expected for a jar file 067 * (in this case it is the same as for a zip file). 068 * 069 * @param signature 070 * the bytes to check 071 * @param length 072 * the number of bytes to check 073 * @return true, if this stream is a jar archive stream, false otherwise 074 */ 075 public static boolean matches(final byte[] signature, final int length ) { 076 return ZipArchiveInputStream.matches(signature, length); 077 } 078}