package org.apache.lucene.queryParser.surround.query;
/**
* 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.
*/
import org.apache.lucene.index.Term;
import org.apache.lucene.index.TermEnum;
import org.apache.lucene.index.IndexReader;
import java.io.IOException;
import java.util.regex.Pattern;
import java.util.regex.Matcher;
public class SrndTruncQuery extends SimpleTerm {
public SrndTruncQuery(String truncated, char unlimited, char mask) {
super(false); /* not quoted */
this.truncated = truncated;
this.unlimited = unlimited;
this.mask = mask;
truncatedToPrefixAndPattern();
}
private final String truncated;
private final char unlimited;
private final char mask;
private String prefix;
private Pattern pattern;
public String getTruncated() {return truncated;}
@Override
public String toStringUnquoted() {return getTruncated();}
protected boolean matchingChar(char c) {
return (c != unlimited) && (c != mask);
}
protected void appendRegExpForChar(char c, StringBuilder re) {
if (c == unlimited)
re.append(".*");
else if (c == mask)
re.append(".");
else
re.append(c);
}
protected void truncatedToPrefixAndPattern() {
int i = 0;
while ((i < truncated.length()) && matchingChar(truncated.charAt(i))) {
i++;
}
prefix = truncated.substring(0, i);
StringBuilder re = new StringBuilder();
while (i < truncated.length()) {
appendRegExpForChar(truncated.charAt(i), re);
i++;
}
pattern = Pattern.compile(re.toString());
}
@Override
public void visitMatchingTerms(
IndexReader reader,
String fieldName,
MatchingTermVisitor mtv) throws IOException
{
int prefixLength = prefix.length();
TermEnum enumerator = reader.terms(new Term(fieldName, prefix));
Matcher matcher = pattern.matcher("");
try {
do {
Term term = enumerator.term();
if (term != null) {
String text = term.text();
if ((! text.startsWith(prefix)) || (! term.field().equals(fieldName))) {
break;
} else {
matcher.reset( text.substring(prefixLength));
if (matcher.matches()) {
mtv.visitMatchingTerm(term);
}
}
}
} while (enumerator.next());
} finally {
enumerator.close();
matcher.reset();
}
}
}