    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     */
    019    package org.apache.commons.compress.archivers.jar;
    020
    021    import java.io.IOException;
    022    import java.io.InputStream;
    023
    024    import org.apache.commons.compress.archivers.ArchiveEntry;
    025    import org.apache.commons.compress.archivers.zip.ZipArchiveEntry;
    026    import 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     */
    033    public class JarArchiveInputStream extends ZipArchiveInputStream {
    034
    035        public JarArchiveInputStream( final InputStream inputStream ) {
    036            super(inputStream);
    037        }
    038
    039        public JarArchiveEntry getNextJarEntry() throws IOException {
    040            ZipArchiveEntry entry = getNextZipEntry();
    041            return entry == null ? null : new JarArchiveEntry(entry);
    042        }
    043
    044        @Override
    045        public ArchiveEntry getNextEntry() throws IOException {
    046            return getNextJarEntry();
    047        }
    048
    049        /**
    050         * Checks if the signature matches what is expected for a jar file
    051         * (in this case it is the same as for a zip file).
    052         *
    053         * @param signature
    054         *            the bytes to check
    055         * @param length
    056         *            the number of bytes to check
    057         * @return true, if this stream is a jar archive stream, false otherwise
    058         */
    059        public static boolean matches(byte[] signature, int length ) {
    060            return ZipArchiveInputStream.matches(signature, length);
    061        }
    062    }