package org.apache.lucene.queries;
/*
* 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.AtomicReaderContext;
import org.apache.lucene.index.DocsEnum;
import org.apache.lucene.index.Term;
import org.apache.lucene.index.Terms;
import org.apache.lucene.index.TermsEnum;
import org.apache.lucene.search.DocIdSet;
import org.apache.lucene.search.DocIdSetIterator;
import org.apache.lucene.search.Filter;
import org.apache.lucene.util.Bits;
import java.io.IOException;
/**
* A filter that includes documents that match with a specific term.
*/
final public class TermFilter extends Filter {
private final Term term;
/**
* @param term The term documents need to have in order to be a match for this filter.
*/
public TermFilter(Term term) {
if (term == null) {
throw new IllegalArgumentException("Term must not be null");
} else if (term.field() == null) {
throw new IllegalArgumentException("Field must not be null");
}
this.term = term;
}
/**
* @return The term this filter includes documents with.
*/
public Term getTerm() {
return term;
}
@Override
public DocIdSet getDocIdSet(AtomicReaderContext context, final Bits acceptDocs) throws IOException {
Terms terms = context.reader().terms(term.field());
if (terms == null) {
return null;
}
final TermsEnum termsEnum = terms.iterator(null);
if (!termsEnum.seekExact(term.bytes())) {
return null;
}
return new DocIdSet() {
@Override
public DocIdSetIterator iterator() throws IOException {
return termsEnum.docs(acceptDocs, null, DocsEnum.FLAG_NONE);
}
};
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
TermFilter that = (TermFilter) o;
if (term != null ? !term.equals(that.term) : that.term != null) return false;
return true;
}
@Override
public int hashCode() {
return term != null ? term.hashCode() : 0;
}
@Override
public String toString() {
return term.field() + ":" + term.text();
}
}