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.zip.ZipArchiveEntry;
025import org.apache.commons.compress.archivers.zip.ZipArchiveInputStream;
026
027/**
028 * Implements an input stream that can read entries from jar files.
029 *
030 * @NotThreadSafe
031 */
032public class JarArchiveInputStream extends ZipArchiveInputStream {
033
034    /**
035     * Checks if the signature matches what is expected for a jar file (in this case it is the same as for a ZIP file).
036     *
037     * @param signature the bytes to check
038     * @param length    the number of bytes to check
039     * @return true, if this stream is a jar archive stream, false otherwise
040     */
041    public static boolean matches(final byte[] signature, final int length) {
042        return ZipArchiveInputStream.matches(signature, length);
043    }
044
045    /**
046     * Creates an instance from the input stream using the default encoding.
047     *
048     * @param inputStream the input stream to wrap
049     */
050    public JarArchiveInputStream(final InputStream inputStream) {
051        super(inputStream);
052    }
053
054    /**
055     * Creates an instance from the input stream using the specified encoding.
056     *
057     * @param inputStream the input stream to wrap
058     * @param encoding    the encoding to use
059     * @since 1.10
060     */
061    public JarArchiveInputStream(final InputStream inputStream, final String encoding) {
062        super(inputStream, encoding);
063    }
064
065    @Override
066    public JarArchiveEntry getNextEntry() throws IOException {
067        return getNextJarEntry();
068    }
069
070    /**
071     * Gets the next entry.
072     *
073     * @return the next entry.
074     * @throws IOException if an I/O error occurs.
075     * @deprecated Use {@link #getNextEntry()}.
076     */
077    @Deprecated
078    public JarArchiveEntry getNextJarEntry() throws IOException {
079        final ZipArchiveEntry entry = getNextZipEntry();
080        return entry == null ? null : new JarArchiveEntry(entry);
081    }
082}