org.apache.tools.zip.ZipEncoding Maven / Gradle / Ivy
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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.tools.zip;
import java.io.IOException;
import java.nio.ByteBuffer;
/**
* An interface for encoders that do a pretty encoding of ZIP
* filenames.
*
* 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 java.lang.String#getBytes(String)
* String.getBytes}, which encodes unknown characters as ASCII
* quotation marks ('?'). Quotation marks are per definition an
* invalid filename 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 filename or ZIP comment.
* @return Whether the given name may be encoded with out any losses.
*/
boolean canEncode(String name);
/**
* Encode a filename 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 filename 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 %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
*/
ByteBuffer encode(String name) throws IOException;
/**
* @param data The byte values to decode.
* @return The decoded string.
* @throws IOException
*/
String decode(byte [] data) throws IOException;
}