package org.apache.lucene.search;
/**
* 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.IndexReader;
import org.apache.lucene.index.Term;
import java.io.IOException;
/** Implements the wildcard search query. Supported wildcards are <code>*</code>, which
* matches any character sequence (including the empty one), and <code>?</code>,
* which matches any single character. Note this query can be slow, as it
* needs to iterate over many terms. In order to prevent extremely slow WildcardQueries,
* a Wildcard term should not start with one of the wildcards <code>*</code> or
* <code>?</code>.
*
* @see WildcardTermEnum
*/
public class WildcardQuery extends MultiTermQuery {
private boolean termContainsWildcard;
public WildcardQuery(Term term) {
super(term);
this.termContainsWildcard = (term.text().indexOf('*') != -1) || (term.text().indexOf('?') != -1);
}
protected FilteredTermEnum getEnum(IndexReader reader) throws IOException {
return new WildcardTermEnum(reader, getTerm());
}
public boolean equals(Object o) {
if (o instanceof WildcardQuery)
return super.equals(o);
return false;
}
public Query rewrite(IndexReader reader) throws IOException {
if (this.termContainsWildcard) {
return super.rewrite(reader);
}
return new TermQuery(getTerm());
}
}
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