001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * https://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.lang3.text.translate; 018 019import java.io.IOException; 020import java.io.Writer; 021 022import org.apache.commons.lang3.CharUtils; 023 024/** 025 * Translate escaped octal Strings back to their octal values. 026 * 027 * For example, "\45" should go back to being the specific value (a %). 028 * 029 * Note that this currently only supports the viable range of octal for Java; namely 030 * 1 to 377. This is because parsing Java is the main use case. 031 * 032 * @since 3.0 033 * @deprecated As of <a href="https://commons.apache.org/proper/commons-lang/changes-report.html#a3.6">3.6</a>, use Apache Commons Text 034 * <a href="https://commons.apache.org/proper/commons-text/javadocs/api-release/org/apache/commons/text/translate/OctalUnescaper.html"> 035 * OctalUnescaper</a>. 036 */ 037@Deprecated 038public class OctalUnescaper extends CharSequenceTranslator { 039 040 /** 041 * Constructs a new instance. 042 */ 043 public OctalUnescaper() { 044 // empty 045 } 046 047 /** 048 * Checks if the given char is the character representation of one of the digit from 0 to 3. 049 * @param ch the char to check 050 * @return true if the given char is the character representation of one of the digits from 0 to 3 051 */ 052 private boolean isZeroToThree(final char ch) { 053 return ch >= '0' && ch <= '3'; 054 } 055 056 /** 057 * {@inheritDoc} 058 */ 059 @Override 060 public int translate(final CharSequence input, final int index, final Writer out) throws IOException { 061 final int remaining = input.length() - index - 1; // how many characters left, ignoring the first \ 062 final StringBuilder builder = new StringBuilder(); 063 if (input.charAt(index) == '\\' && remaining > 0 && CharUtils.isOctal(input.charAt(index + 1))) { 064 final int next = index + 1; 065 final int next2 = index + 2; 066 final int next3 = index + 3; 067 // we know this is good as we checked it in the if block above 068 builder.append(input.charAt(next)); 069 if (remaining > 1 && CharUtils.isOctal(input.charAt(next2))) { 070 builder.append(input.charAt(next2)); 071 if (remaining > 2 && isZeroToThree(input.charAt(next)) && CharUtils.isOctal(input.charAt(next3))) { 072 builder.append(input.charAt(next3)); 073 } 074 } 075 out.write(Integer.parseInt(builder.toString(), 8)); 076 return 1 + builder.length(); 077 } 078 return 0; 079 } 080}