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/*
* 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.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 Apache 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.
*
* @param lookup CharSequence[][] table of size [*][2]
*/
public LookupTranslator(final CharSequence[]... lookup) {
lookupMap = new HashMap<>();
prefixSet = new HashSet<>();
int tmpShortest = Integer.MAX_VALUE;
int tmpLongest = 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 < tmpShortest) {
tmpShortest = sz;
}
if (sz > tmpLongest) {
tmpLongest = sz;
}
}
}
this.shortest = tmpShortest;
this.longest = tmpLongest;
}
/**
* {@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;
}
}
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