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