/*
* 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.jackrabbit.core.query.lucene;
import java.io.IOException;
import org.apache.lucene.analysis.ASCIIFoldingFilter;
import org.apache.lucene.search.FieldComparator;
import org.apache.lucene.search.FieldComparatorSource;
/**
* <code>NormalizeSortComparator</code> implements a <code>FieldComparator</code> which
* compares the lower-cased and normalized string values of a base sort comparator.
*/
public class NormalizeSortComparator extends FieldComparatorSource {
/**
* The base sort comparator.
*/
private final FieldComparatorSource base;
/**
* Creates a new upper case sort comparator.
*
* @param base the base sort comparator source.
*/
public NormalizeSortComparator(FieldComparatorSource base) {
this.base = base;
}
@Override
public FieldComparator<?> newComparator(
String fieldname, int numHits, int sortPos, boolean reversed)
throws IOException {
FieldComparator<?> comparator =
base.newComparator(fieldname, numHits, sortPos, reversed);
assert comparator instanceof FieldComparatorBase;
return new FieldComparatorDecorator((FieldComparatorBase) comparator) {
@Override
protected Comparable<?> sortValue(int doc) {
Comparable<?> comparable = super.sortValue(doc);
if (comparable != null) {
char[] input = comparable.toString().toCharArray();
// Normalize to ASCII using Lucene's ASCIIFoldingFilter
char[] output = new char[input.length * 4]; // worst-case
int length = ASCIIFoldingFilter.foldToASCII(
input, 0, output, 0, input.length);
// Convert to lower case, and check if output is different
boolean different = length != input.length;
for (int i = 0; i < length; i++) {
char c = output[i];
if ('A'<= c && c <= 'Z') {
output[i] = (char) (c + 'a' - 'A');
}
if (!different && input[i] != output[i]) {
different = true;
}
}
if (different) {
comparable = new String(output, 0, length);
}
}
return comparable;
}
};
}
}