UnrecognizedExtraField.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.commons.compress.archivers.zip;

import java.util.Arrays;

/**
 * Simple placeholder for all those extra fields we don't want to deal with.
 *
 * <p>
 * Assumes local file data and central directory entries are identical - unless told the opposite.
 * </p>
 *
 * @NotThreadSafe
 */
public class UnrecognizedExtraField implements ZipExtraField {

    /**
     * The Header-ID.
     */
    private ZipShort headerId;

    /**
     * Extra field data in local file data - without Header-ID or length specifier.
     */
    private byte[] localData;

    /**
     * Extra field data in central directory - without Header-ID or length specifier.
     */
    private byte[] centralData;

    /**
     * Gets the central data.
     *
     * @return the central data if present, else return the local file data
     */
    @Override
    public byte[] getCentralDirectoryData() {
        if (centralData != null) {
            return ZipUtil.copy(centralData);
        }
        return getLocalFileDataData();
    }

    /**
     * Gets the central data length. If there is no central data, get the local file data length.
     *
     * @return the central data length
     */
    @Override
    public ZipShort getCentralDirectoryLength() {
        if (centralData != null) {
            return new ZipShort(centralData.length);
        }
        return getLocalFileDataLength();
    }

    /**
     * Gets the header id.
     *
     * @return the header id
     */
    @Override
    public ZipShort getHeaderId() {
        return headerId;
    }

    /**
     * Gets the local data.
     *
     * @return the local data
     */
    @Override
    public byte[] getLocalFileDataData() {
        return ZipUtil.copy(localData);
    }

    /**
     * Gets the length of the local data.
     *
     * @return the length of the local data
     */
    @Override
    public ZipShort getLocalFileDataLength() {
        return new ZipShort(localData != null ? localData.length : 0);
    }

    /**
     * @param data   the array of bytes.
     * @param offset the source location in the data array.
     * @param length the number of bytes to use in the data array.
     * @see ZipExtraField#parseFromCentralDirectoryData(byte[], int, int)
     */
    @Override
    public void parseFromCentralDirectoryData(final byte[] data, final int offset, final int length) {
        final byte[] tmp = Arrays.copyOfRange(data, offset, offset + length);
        setCentralDirectoryData(tmp);
        if (localData == null) {
            setLocalFileDataData(tmp);
        }
    }

    /**
     * @param data   the array of bytes.
     * @param offset the source location in the data array.
     * @param length the number of bytes to use in the data array.
     * @see ZipExtraField#parseFromLocalFileData(byte[], int, int)
     */
    @Override
    public void parseFromLocalFileData(final byte[] data, final int offset, final int length) {
        setLocalFileDataData(Arrays.copyOfRange(data, offset, offset + length));
    }

    /**
     * Sets the extra field data in central directory.
     *
     * @param data the data to use
     */
    public void setCentralDirectoryData(final byte[] data) {
        centralData = ZipUtil.copy(data);
    }

    /**
     * Sets the header id.
     *
     * @param headerId the header id to use
     */
    public void setHeaderId(final ZipShort headerId) {
        this.headerId = headerId;
    }

    /**
     * Sets the extra field data in the local file data - without Header-ID or length specifier.
     *
     * @param data the field data to use
     */
    public void setLocalFileDataData(final byte[] data) {
        localData = ZipUtil.copy(data);
    }

}