/* | |
* 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.commons.text.translate; | |
import java.io.IOException; | |
import java.io.Writer; | |
import org.apache.commons.lang3.CharUtils; | |
import org.apache.commons.lang3.StringUtils; | |
/** | |
* This class holds inner classes for escaping/unescaping Comma Separated Values. | |
* <p> | |
* In general the use a high level API like <a href="https://commons.apache.org/proper/commons-csv/">Apache Commons | |
* CSV</a> should be preferred over these low level classes. | |
* </p> | |
* | |
* @see <a href="https://commons.apache.org/proper/commons-csv/apidocs/index.html">Apache Commons CSV</a> | |
*/ | |
public final class CsvTranslators { | |
/** Comma character. */ | |
private static final char CSV_DELIMITER = ','; | |
/** Quote character. */ | |
private static final char CSV_QUOTE = '"'; | |
/** Quote character converted to string. */ | |
private static final String CSV_QUOTE_STR = String.valueOf(CSV_QUOTE); | |
/** Escaped quote string. */ | |
private static final String CSV_ESCAPED_QUOTE_STR = CSV_QUOTE_STR + CSV_QUOTE_STR; | |
/** CSV key characters in an array. */ | |
private static final char[] CSV_SEARCH_CHARS = | |
new char[] {CSV_DELIMITER, CSV_QUOTE, CharUtils.CR, CharUtils.LF}; | |
/** Hidden constructor. */ | |
private CsvTranslators() { } | |
/** | |
* Translator for escaping Comma Separated Values. | |
*/ | |
public static class CsvEscaper extends SinglePassTranslator { | |
@Override | |
void translateWhole(final CharSequence input, final Writer out) throws IOException { | |
final String inputSting = input.toString(); | |
if (StringUtils.containsNone(inputSting, CSV_SEARCH_CHARS)) { | |
out.write(inputSting); | |
} else { | |
// input needs quoting | |
out.write(CSV_QUOTE); | |
out.write(StringUtils.replace(inputSting, CSV_QUOTE_STR, CSV_ESCAPED_QUOTE_STR)); | |
out.write(CSV_QUOTE); | |
} | |
} | |
} | |
/** | |
* Translator for unescaping escaped Comma Separated Value entries. | |
*/ | |
public static class CsvUnescaper extends SinglePassTranslator { | |
@Override | |
void translateWhole(final CharSequence input, final Writer out) throws IOException { | |
// is input not quoted? | |
if (input.charAt(0) != CSV_QUOTE || input.charAt(input.length() - 1) != CSV_QUOTE) { | |
out.write(input.toString()); | |
return; | |
} | |
// strip quotes | |
final String quoteless = input.subSequence(1, input.length() - 1).toString(); | |
if (StringUtils.containsAny(quoteless, CSV_SEARCH_CHARS)) { | |
// deal with escaped quotes; ie) "" | |
out.write(StringUtils.replace(quoteless, CSV_ESCAPED_QUOTE_STR, CSV_QUOTE_STR)); | |
} else { | |
out.write(input.toString()); | |
} | |
} | |
} | |
} |