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 * http://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.text.translate; 018 019import org.apache.commons.lang3.CharUtils; 020import org.apache.commons.lang3.StringUtils; 021 022import java.io.IOException; 023import java.io.Writer; 024 025/** 026 * This class holds inner classes for escaping/unescaping Comma Separated Values. 027 */ 028public final class CsvTranslators { 029 030 /** Comma character. */ 031 private static final char CSV_DELIMITER = ','; 032 /** Quote character. */ 033 private static final char CSV_QUOTE = '"'; 034 /** Quote character converted to string. */ 035 private static final String CSV_QUOTE_STR = String.valueOf(CSV_QUOTE); 036 /** Escaped quote string. */ 037 private static final String CSV_ESCAPED_QUOTE_STR = CSV_QUOTE_STR + CSV_QUOTE_STR; 038 /** CSV key characters in an array. */ 039 private static final char[] CSV_SEARCH_CHARS = 040 new char[] {CSV_DELIMITER, CSV_QUOTE, CharUtils.CR, CharUtils.LF}; 041 042 /** Hidden constructor. */ 043 private CsvTranslators() { } 044 045 /** 046 * Translator for escaping Comma Separated Values. 047 */ 048 public static class CsvEscaper extends SinglePassTranslator { 049 050 @Override 051 void translateWhole(final CharSequence input, final Writer out) throws IOException { 052 final String inputSting = input.toString(); 053 if (StringUtils.containsNone(inputSting, CSV_SEARCH_CHARS)) { 054 out.write(inputSting); 055 } else { 056 // input needs quoting 057 out.write(CSV_QUOTE); 058 out.write(StringUtils.replace(inputSting, CSV_QUOTE_STR, CSV_ESCAPED_QUOTE_STR)); 059 out.write(CSV_QUOTE); 060 } 061 } 062 } 063 064 /** 065 * Translator for unescaping escaped Comma Separated Value entries. 066 */ 067 public static class CsvUnescaper extends SinglePassTranslator { 068 069 @Override 070 void translateWhole(final CharSequence input, final Writer out) throws IOException { 071 // is input not quoted? 072 if (input.charAt(0) != CSV_QUOTE || input.charAt(input.length() - 1) != CSV_QUOTE) { 073 out.write(input.toString()); 074 return; 075 } 076 077 // strip quotes 078 final String quoteless = input.subSequence(1, input.length() - 1).toString(); 079 080 if (StringUtils.containsAny(quoteless, CSV_SEARCH_CHARS)) { 081 // deal with escaped quotes; ie) "" 082 out.write(StringUtils.replace(quoteless, CSV_ESCAPED_QUOTE_STR, CSV_QUOTE_STR)); 083 } else { 084 out.write(input.toString()); 085 } 086 } 087 } 088}