108 lines
4.3 KiB
Java
108 lines
4.3 KiB
Java
/*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership.
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* The ASF licenses this file to You under the Apache License, Version 2.0
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* (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package org.apache.commons.text.translate;
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import java.io.IOException;
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import java.io.Writer;
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import org.apache.commons.lang3.CharUtils;
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import org.apache.commons.lang3.StringUtils;
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/**
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* This class holds inner classes for escaping/unescaping Comma Separated Values.
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* <p>
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* In general the use a high level API like <a href="https://commons.apache.org/proper/commons-csv/">Apache Commons
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* CSV</a> should be preferred over these low level classes.
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* </p>
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*
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* @see <a href="https://commons.apache.org/proper/commons-csv/apidocs/index.html">Apache Commons CSV</a>
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*/
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public final class CsvTranslators {
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/**
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* Translator for escaping Comma Separated Values.
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*/
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public static class CsvEscaper extends SinglePassTranslator {
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@Override
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void translateWhole(final CharSequence input, final Writer writer) throws IOException {
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final String inputSting = input.toString();
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if (StringUtils.containsNone(inputSting, CSV_SEARCH_CHARS)) {
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writer.write(inputSting);
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} else {
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// input needs quoting
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writer.write(CSV_QUOTE);
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writer.write(StringUtils.replace(inputSting, CSV_QUOTE_STR, CSV_ESCAPED_QUOTE_STR));
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writer.write(CSV_QUOTE);
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}
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}
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}
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/**
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* Translator for unescaping escaped Comma Separated Value entries.
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*/
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public static class CsvUnescaper extends SinglePassTranslator {
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@Override
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void translateWhole(final CharSequence input, final Writer writer) throws IOException {
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final int zeroIndex = 0;
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final int oneIndex = 1;
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final int lastIndex = input.length() - 1;
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// unfortunately there is no way to encode non-empty length
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assert zeroIndex < input.length() && lastIndex >= 0 :
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"@AssumeAssertion(index): translateWhole is called by " +
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"SinglePassTranslator.translate(CharSequence, int, Writer), and that is part of a template method" +
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"implementation that by contract is called only with non-empty `input` CharSequences";
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// is input not quoted?
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if (input.charAt(zeroIndex) != CSV_QUOTE || input.charAt(lastIndex) != CSV_QUOTE) {
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writer.write(input.toString());
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return;
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}
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if (oneIndex >= input.length()) {
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throw new IllegalArgumentException("input length should be at least 2");
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}
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// strip quotes
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final String quoteless = input.subSequence(oneIndex, lastIndex).toString();
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if (StringUtils.containsAny(quoteless, CSV_SEARCH_CHARS)) {
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// deal with escaped quotes; ie) ""
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writer.write(StringUtils.replace(quoteless, CSV_ESCAPED_QUOTE_STR, CSV_QUOTE_STR));
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} else {
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writer.write(quoteless);
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}
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}
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}
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/** Comma character. */
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private static final char CSV_DELIMITER = ',';
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/** Quote character. */
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private static final char CSV_QUOTE = '"';
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/** Quote character converted to string. */
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private static final String CSV_QUOTE_STR = String.valueOf(CSV_QUOTE);
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/** Escaped quote string. */
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private static final String CSV_ESCAPED_QUOTE_STR = CSV_QUOTE_STR + CSV_QUOTE_STR;
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/** CSV key characters in an array. */
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private static final char[] CSV_SEARCH_CHARS = { CSV_DELIMITER, CSV_QUOTE, CharUtils.CR, CharUtils.LF };
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/** Hidden constructor. */
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private CsvTranslators() { }
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}
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