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
036     * (in this case it is the same as for a ZIP file).
037     *
038     * @param signature
039     *            the bytes to check
040     * @param length
041     *            the number of bytes to check
042     * @return true, if this stream is a jar archive stream, false otherwise
043     */
044    public static boolean matches(final byte[] signature, final int length ) {
045        return ZipArchiveInputStream.matches(signature, length);
046    }
047
048    /**
049     * Creates an instance from the input stream using the default encoding.
050     *
051     * @param inputStream the input stream to wrap
052     */
053    public JarArchiveInputStream( final InputStream inputStream ) {
054        super(inputStream);
055    }
056
057    /**
058     * Creates an instance from the input stream using the specified encoding.
059     *
060     * @param inputStream the input stream to wrap
061     * @param encoding the encoding to use
062     * @since 1.10
063     */
064    public JarArchiveInputStream( final InputStream inputStream, final String encoding ) {
065        super(inputStream, encoding);
066    }
067
068    @Override
069    public JarArchiveEntry getNextEntry() throws IOException {
070        return getNextJarEntry();
071    }
072
073    /**
074     * Gets the next entry.
075     *
076     * @return the next entry.
077     * @throws IOException
078     * @deprecated Use {@link #getNextEntry()}.
079     */
080    @Deprecated
081    public JarArchiveEntry getNextJarEntry() throws IOException {
082        final ZipArchiveEntry entry = getNextZipEntry();
083        return entry == null ? null : new JarArchiveEntry(entry);
084    }
085}