1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, 13 * software distributed under the License is distributed on an 14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 15 * KIND, either express or implied. See the License for the 16 * specific language governing permissions and limitations 17 * under the License. 18 */ 19 20 package org.apache.commons.compress.archivers.zip; 21 22 import java.io.IOException; 23 import java.nio.ByteBuffer; 24 25 /** 26 * An interface for encoders that do a pretty encoding of ZIP 27 * filenames. 28 * 29 * <p>There are mostly two implementations, one that uses java.nio 30 * {@link java.nio.charset.Charset Charset} and one implementation, 31 * which copes with simple 8 bit charsets, because java-1.4 did not 32 * support Cp437 in java.nio.</p> 33 * 34 * <p>The main reason for defining an own encoding layer comes from 35 * the problems with {@link java.lang.String#getBytes(String) 36 * String.getBytes}, which encodes unknown characters as ASCII 37 * quotation marks ('?'). Quotation marks are per definition an 38 * invalid filename on some operating systems like Windows, which 39 * leads to ignored ZIP entries.</p> 40 * 41 * <p>All implementations should implement this interface in a 42 * reentrant way.</p> 43 */ 44 public interface ZipEncoding { 45 /** 46 * Check, whether the given string may be losslessly encoded using this 47 * encoding. 48 * 49 * @param name A filename or ZIP comment. 50 * @return Whether the given name may be encoded with out any losses. 51 */ canEncode(String name)52 boolean canEncode(String name); 53 54 /** 55 * Encode a filename or a comment to a byte array suitable for 56 * storing it to a serialized zip entry. 57 * 58 * <p>Examples for CP 437 (in pseudo-notation, right hand side is 59 * C-style notation):</p> 60 * <pre> 61 * encode("\u20AC_for_Dollar.txt") = "%U20AC_for_Dollar.txt" 62 * encode("\u00D6lf\u00E4sser.txt") = "\231lf\204sser.txt" 63 * </pre> 64 * 65 * @param name A filename or ZIP comment. 66 * @return A byte buffer with a backing array containing the 67 * encoded name. Unmappable characters or malformed 68 * character sequences are mapped to a sequence of utf-16 69 * words encoded in the format <code>%Uxxxx</code>. It is 70 * assumed, that the byte buffer is positioned at the 71 * beginning of the encoded result, the byte buffer has a 72 * backing array and the limit of the byte buffer points 73 * to the end of the encoded result. 74 * @throws IOException on error 75 */ encode(String name)76 ByteBuffer encode(String name) throws IOException; 77 78 /** 79 * @param data The byte values to decode. 80 * @return The decoded string. 81 * @throws IOException on error 82 */ decode(byte [] data)83 String decode(byte [] data) throws IOException; 84 } 85