    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.zip;
    020
    021    import java.util.zip.ZipException;
    022
    023    /**
    024     * General format of extra field data. <p>
    025     *
    026     * Extra fields usually appear twice per file, once in the local file data and
    027     * once in the central directory. Usually they are the same, but they don't have
    028     * to be. {@link java.util.zip.ZipOutputStream java.util.zip.ZipOutputStream}
    029     * will only use the local file data in both places.</p>
    030     */
    031    public interface ZipExtraField {
    032        /**
    033         * The Header-ID.
    034         *
    035         * @return The HeaderId value
    036         */
    037        ZipShort getHeaderId();
    038
    039        /**
    040         * Length of the extra field in the local file data - without Header-ID or
    041         * length specifier.
    042         *
    043         * @return The LocalFileDataLength value
    044         */
    045        ZipShort getLocalFileDataLength();
    046
    047        /**
    048         * Length of the extra field in the central directory - without Header-ID or
    049         * length specifier.
    050         *
    051         * @return The CentralDirectoryLength value
    052         */
    053        ZipShort getCentralDirectoryLength();
    054
    055        /**
    056         * The actual data to put into local file data - without Header-ID or length
    057         * specifier.
    058         *
    059         * @return The LocalFileDataData value
    060         */
    061        byte[] getLocalFileDataData();
    062
    063        /**
    064         * The actual data to put into central directory - without Header-ID or
    065         * length specifier.
    066         *
    067         * @return The CentralDirectoryData value
    068         */
    069        byte[] getCentralDirectoryData();
    070
    071        /**
    072         * Populate data from this array as if it was in local file data.
    073         *
    074         * @param buffer the buffer to read data from
    075         * @param offset offset into buffer to read data
    076         * @param length the length of data
    077         * @exception ZipException on error
    078         */
    079        void parseFromLocalFileData(byte[] buffer, int offset, int length)
    080            throws ZipException;
    081
    082        /**
    083         * Populate data from this array as if it was in central directory data.
    084         *
    085         * @param buffer the buffer to read data from
    086         * @param offset offset into buffer to read data
    087         * @param length the length of data
    088         * @exception ZipException on error
    089         */
    090        void parseFromCentralDirectoryData(byte[] buffer, int offset, int length)
    091            throws ZipException;
    092    }