https://ant.apache.org/: master POM (The Apache Software Foundation) 
/*
 *  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
 *
 *      https://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.tools.zip;

import java.util.zip.ZipException;


General format of extra field data.

Extra fields usually appear twice per file, once in the local file data and once in the central directory. Usually they are the same, but they don't have to be. java.util.zip.ZipOutputStream will only use the local file data in both places.


/**
 * General format of extra field data.
 *
 * <p>Extra fields usually appear twice per file, once in the local
 * file data and once in the central directory.  Usually they are the
 * same, but they don't have to be.  {@link
 * java.util.zip.ZipOutputStream java.util.zip.ZipOutputStream} will
 * only use the local file data in both places.</p>
 *
 */
public interface ZipExtraField {

    
The Header-ID.

Returns:the header id
Since:1.1
/**
     * The Header-ID.
     * @return the header id
     * @since 1.1
     */
    ZipShort getHeaderId();

    
Length of the extra field in the local file data - without
Header-ID or length specifier.

Returns:the length of the field in the local file data
Since:1.1
/**
     * Length of the extra field in the local file data - without
     * Header-ID or length specifier.
     * @return the length of the field in the local file data
     * @since 1.1
     */
    ZipShort getLocalFileDataLength();

    
Length of the extra field in the central directory - without
Header-ID or length specifier.

Returns:the length of the field in the central directory
Since:1.1
/**
     * Length of the extra field in the central directory - without
     * Header-ID or length specifier.
     * @return the length of the field in the central directory
     * @since 1.1
     */
    ZipShort getCentralDirectoryLength();

    
The actual data to put into local file data - without Header-ID
or length specifier.

Returns:the data
Since:1.1
/**
     * The actual data to put into local file data - without Header-ID
     * or length specifier.
     * @return the data
     * @since 1.1
     */
    byte[] getLocalFileDataData();

    
The actual data to put into central directory - without Header-ID or
length specifier.

Returns:the data
Since:1.1
/**
     * The actual data to put into central directory - without Header-ID or
     * length specifier.
     * @return the data
     * @since 1.1
     */
    byte[] getCentralDirectoryData();

    
Populate data from this array as if it was in local file data.

Params:
  • data – an array of bytes
  • offset – the start offset
  • length – the number of bytes in the array from offset
Throws:
Since:1.1
/**
     * Populate data from this array as if it was in local file data.
     * @param data an array of bytes
     * @param offset the start offset
     * @param length the number of bytes in the array from offset
     *
     * @since 1.1
     * @throws ZipException on error
     */
    void parseFromLocalFileData(byte[] data, int offset, int length)
        throws ZipException;
}