/*
* 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;
/**
* Translates a value using a lookup table.
*
* @since 3.0
* @version $Id: LookupTranslator.java 1091096 2011-04-11 15:07:29Z mbenson $
*/
public class LookupTranslator extends CharSequenceTranslator {
private final HashMap<CharSequence, CharSequence> lookupMap;
private final int shortest;
private final int longest;
/**
* Define the lookup table to be used in translation
*
* @param lookup CharSequence[][] table of size [*][2]
*/
public LookupTranslator(CharSequence[]... lookup) {
lookupMap = new HashMap<CharSequence, CharSequence>();
int _shortest = Integer.MAX_VALUE;
int _longest = 0;
if (lookup != null) {
for (CharSequence[] seq : lookup) {
this.lookupMap.put(seq[0], seq[1]);
int sz = seq[0].length();
if (sz < _shortest) {
_shortest = sz;
}
if (sz > _longest) {
_longest = sz;
}
}
}
shortest = _shortest;
longest = _longest;
}
/**
* {@inheritDoc}
*/
@Override
public int translate(CharSequence input, int index, Writer out) throws IOException {
int max = longest;
if (index + longest > input.length()) {
max = input.length() - index;
}
// descend so as to get a greedy algorithm
for (int i = max; i >= shortest; i--) {
CharSequence subSeq = input.subSequence(index, index + i);
CharSequence result = lookupMap.get(subSeq);
if (result != null) {
out.write(result.toString());
return i;
}
}
return 0;
}
}
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