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 * 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
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 *      http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.commons.lang3.text.translate;

import java.io.IOException;
import java.io.Writer;
import java.util.HashMap;
import java.util.HashSet;

Translates a value using a lookup table.
Since:3.0
Deprecated:as of 3.6, use commons-text LookupTranslator instead
/** * Translates a value using a lookup table. * * @since 3.0 * @deprecated as of 3.6, use commons-text * <a href="https://commons.apache.org/proper/commons-text/javadocs/api-release/org/apache/commons/text/translate/LookupTranslator.html"> * LookupTranslator</a> instead */
@Deprecated public class LookupTranslator extends CharSequenceTranslator { private final HashMap<String, String> lookupMap; private final HashSet<Character> prefixSet; private final int shortest; private final int longest;
Define the lookup table to be used in translation Note that, as of Lang 3.1, the key to the lookup table is converted to a java.lang.String. This is because we need the key to support hashCode and equals(Object), allowing it to be the key for a HashMap. See LANG-882.
Params:
  • lookup – CharSequence[][] table of size [*][2]
/** * Define the lookup table to be used in translation * * Note that, as of Lang 3.1, the key to the lookup table is converted to a * java.lang.String. This is because we need the key to support hashCode and * equals(Object), allowing it to be the key for a HashMap. See LANG-882. * * @param lookup CharSequence[][] table of size [*][2] */
public LookupTranslator(final CharSequence[]... lookup) { lookupMap = new HashMap<>(); prefixSet = new HashSet<>(); int _shortest = Integer.MAX_VALUE; int _longest = 0; if (lookup != null) { for (final CharSequence[] seq : lookup) { this.lookupMap.put(seq[0].toString(), seq[1].toString()); this.prefixSet.add(seq[0].charAt(0)); final int sz = seq[0].length(); if (sz < _shortest) { _shortest = sz; } if (sz > _longest) { _longest = sz; } } } shortest = _shortest; longest = _longest; }
{@inheritDoc}
/** * {@inheritDoc} */
@Override public int translate(final CharSequence input, final int index, final Writer out) throws IOException { // check if translation exists for the input at position index if (prefixSet.contains(input.charAt(index))) { int max = longest; if (index + longest > input.length()) { max = input.length() - index; } // implement greedy algorithm by trying maximum match first for (int i = max; i >= shortest; i--) { final CharSequence subSeq = input.subSequence(index, index + i); final String result = lookupMap.get(subSeq.toString()); if (result != null) { out.write(result); return i; } } } return 0; } }