    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.zip;
    020
    021import java.util.Arrays;
    022
    023/**
    024 * Wrapper for extra field data that doesn't conform to the recommended format of header-tag + size + data.
    025 *
    026 * <p>The header-id is artificial (and not listed as a known ID in <a
    027 * href="https://www.pkware.com/documents/casestudies/APPNOTE.TXT">APPNOTE.TXT</a>).  Since it isn't used anywhere
    028 * except to satisfy the ZipExtraField contract it shouldn't matter anyway.</p>
    029 *
    030 * @since 1.1
    031 * @NotThreadSafe
    032 */
    033public final class UnparseableExtraFieldData implements ZipExtraField {
    034    private static final ZipShort HEADER_ID = new ZipShort(0xACC1);
    035
    036    private byte[] localFileData;
    037    private byte[] centralDirectoryData;
    038
    039    /**
    040     * The Header-ID.
    041     *
    042     * @return a completely arbitrary value that should be ignored.
    043     */
    044    @Override
    045    public ZipShort getHeaderId() {
    046        return HEADER_ID;
    047    }
    048
    049    /**
    050     * Length of the complete extra field in the local file data.
    051     *
    052     * @return The LocalFileDataLength value
    053     */
    054    @Override
    055    public ZipShort getLocalFileDataLength() {
    056        return new ZipShort(localFileData == null ? 0 : localFileData.length);
    057    }
    058
    059    /**
    060     * Length of the complete extra field in the central directory.
    061     *
    062     * @return The CentralDirectoryLength value
    063     */
    064    @Override
    065    public ZipShort getCentralDirectoryLength() {
    066        return centralDirectoryData == null
    067            ? getLocalFileDataLength()
    068            : new ZipShort(centralDirectoryData.length);
    069    }
    070
    071    /**
    072     * The actual data to put into local file data.
    073     *
    074     * @return The LocalFileDataData value
    075     */
    076    @Override
    077    public byte[] getLocalFileDataData() {
    078        return ZipUtil.copy(localFileData);
    079    }
    080
    081    /**
    082     * The actual data to put into central directory.
    083     *
    084     * @return The CentralDirectoryData value
    085     */
    086    @Override
    087    public byte[] getCentralDirectoryData() {
    088        return centralDirectoryData == null
    089            ? getLocalFileDataData() : ZipUtil.copy(centralDirectoryData);
    090    }
    091
    092    /**
    093     * Populate data from this array as if it was in local file data.
    094     *
    095     * @param buffer the buffer to read data from
    096     * @param offset offset into buffer to read data
    097     * @param length the length of data
    098     */
    099    @Override
    100    public void parseFromLocalFileData(final byte[] buffer, final int offset, final int length) {
    101        localFileData = Arrays.copyOfRange(buffer, offset, offset + length);
    102    }
    103
    104    /**
    105     * Populate data from this array as if it was in central directory data.
    106     *
    107     * @param buffer the buffer to read data from
    108     * @param offset offset into buffer to read data
    109     * @param length the length of data
    110     */
    111    @Override
    112    public void parseFromCentralDirectoryData(final byte[] buffer, final int offset,
    113                                              final int length) {
    114        centralDirectoryData = Arrays.copyOfRange(buffer, offset, offset + length);
    115        if (localFileData == null) {
    116            parseFromLocalFileData(buffer, offset, length);
    117        }
    118    }
    119
    120}