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 */ 019 020package org.apache.commons.compress.archivers.zip; 021 022import java.io.IOException; 023import java.nio.ByteBuffer; 024 025/** 026 * An interface for encoders that do a pretty encoding of ZIP 027 * filenames. 028 * 029 * <p>There are mostly two implementations, one that uses java.nio 030 * {@link java.nio.charset.Charset Charset} and one implementation, 031 * which copes with simple 8 bit charsets, because java-1.4 did not 032 * support Cp437 in java.nio.</p> 033 * 034 * <p>The main reason for defining an own encoding layer comes from 035 * the problems with {@link java.lang.String#getBytes(String) 036 * String.getBytes}, which encodes unknown characters as ASCII 037 * quotation marks ('?'). Quotation marks are per definition an 038 * invalid filename on some operating systems like Windows, which 039 * leads to ignored ZIP entries.</p> 040 * 041 * <p>All implementations should implement this interface in a 042 * reentrant way.</p> 043 */ 044public interface ZipEncoding { 045 /** 046 * Check, whether the given string may be losslessly encoded using this 047 * encoding. 048 * 049 * @param name A filename or ZIP comment. 050 * @return Whether the given name may be encoded with out any losses. 051 */ 052 boolean canEncode(String name); 053 054 /** 055 * Encode a filename or a comment to a byte array suitable for 056 * storing it to a serialized zip entry. 057 * 058 * <p>Examples for CP 437 (in pseudo-notation, right hand side is 059 * C-style notation):</p> 060 * <pre> 061 * encode("\u20AC_for_Dollar.txt") = "%U20AC_for_Dollar.txt" 062 * encode("\u00D6lf\u00E4sser.txt") = "\231lf\204sser.txt" 063 * </pre> 064 * 065 * @param name A filename or ZIP comment. 066 * @return A byte buffer with a backing array containing the 067 * encoded name. Unmappable characters or malformed 068 * character sequences are mapped to a sequence of utf-16 069 * words encoded in the format <code>%Uxxxx</code>. It is 070 * assumed, that the byte buffer is positioned at the 071 * beginning of the encoded result, the byte buffer has a 072 * backing array and the limit of the byte buffer points 073 * to the end of the encoded result. 074 * @throws IOException on error 075 */ 076 ByteBuffer encode(String name) throws IOException; 077 078 /** 079 * @param data The byte values to decode. 080 * @return The decoded string. 081 * @throws IOException on error 082 */ 083 String decode(byte [] data) throws IOException; 084}