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Apache Commons Compress defines an API for working with compression and archive formats. These include bzip2, gzip, pack200, LZMA, XZ, Snappy, traditional Unix Compress, DEFLATE, DEFLATE64, LZ4, Brotli, Zstandard and ar, cpio, jar, tar, zip, dump, 7z, arj.

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/*
 * 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.io.IOException;
import java.nio.ByteBuffer;

/**
 * An interface for encoders that do a pretty encoding of ZIP file names.
 *
 * 
 * There are mostly two implementations, one that uses java.nio {@link java.nio.charset.Charset Charset} and one implementation, which copes with simple 8 bit
 * charsets, because java-1.4 did not support Cp437 in java.nio.
 * 
 *
 * 
 * The main reason for defining an own encoding layer comes from the problems with {@link String#getBytes(String) String.getBytes}, which encodes
 * unknown characters as ASCII quotation marks ('?'). Quotation marks are per definition an invalid file name on some operating systems like Windows, which
 * leads to ignored ZIP entries.
 * 
 *
 * 
 * All implementations should implement this interface in a reentrant way.
 * 
 */
public interface ZipEncoding {
    /**
     * Check, whether the given string may be losslessly encoded using this encoding.
     *
     * @param name A file name or ZIP comment.
     * @return Whether the given name may be encoded without any losses.
     */
    boolean canEncode(String name);

    /**
     * @param data The byte values to decode.
     * @return The decoded string.
     * @throws IOException on error
     */
    String decode(byte[] data) throws IOException;

    /**
     * Encode a file name or a comment to a byte array suitable for storing it to a serialized ZIP entry.
     *
     * 
     * Examples for CP 437 (in pseudo-notation, right hand side is C-style notation):
     * 
     *
     *      *  encode("\u20AC_for_Dollar.txt") = "%U20AC_for_Dollar.txt"
     *  encode("\u00D6lf\u00E4sser.txt") = "\231lf\204sser.txt"
     * 
     *
     * @param name A file name or ZIP comment.
     * @return A byte buffer with a backing array containing the encoded name. Unmappable characters or malformed character sequences are mapped to a sequence
     *         of utf-16 words encoded in the format {@code %Uxxxx}. It is assumed, that the byte buffer is positioned at the beginning of the encoded result,
     *         the byte buffer has a backing array and the limit of the byte buffer points to the end of the encoded result.
     * @throws IOException on error
     */
    ByteBuffer encode(String name) throws IOException;
}