package org.apache.lucene.search.spans;
/*
* 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.Fields;
import org.apache.lucene.index.Term;
import org.apache.lucene.index.DocsAndPositionsEnum;
import org.apache.lucene.index.TermContext;
import org.apache.lucene.index.TermState;
import org.apache.lucene.index.Terms;
import org.apache.lucene.index.TermsEnum;
import org.apache.lucene.util.Bits;
import org.apache.lucene.util.ToStringUtils;
import java.io.IOException;
import java.util.Map;
import java.util.Set;
/** Matches spans containing a term. */
public class SpanTermQuery extends SpanQuery {
protected Term term;
/** Construct a SpanTermQuery matching the named term's spans. */
public SpanTermQuery(Term term) { this.term = term; }
/** Return the term whose spans are matched. */
public Term getTerm() { return term; }
@Override
public String getField() { return term.field(); }
@Override
public void extractTerms(Set<Term> terms) {
terms.add(term);
}
@Override
public String toString(String field) {
StringBuilder buffer = new StringBuilder();
if (term.field().equals(field))
buffer.append(term.text());
else
buffer.append(term.toString());
buffer.append(ToStringUtils.boost(getBoost()));
return buffer.toString();
}
@Override
public int hashCode() {
final int prime = 31;
int result = super.hashCode();
result = prime * result + ((term == null) ? 0 : term.hashCode());
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (!super.equals(obj))
return false;
if (getClass() != obj.getClass())
return false;
SpanTermQuery other = (SpanTermQuery) obj;
if (term == null) {
if (other.term != null)
return false;
} else if (!term.equals(other.term))
return false;
return true;
}
@Override
public Spans getSpans(final AtomicReaderContext context, Bits acceptDocs, Map<Term,TermContext> termContexts) throws IOException {
TermContext termContext = termContexts.get(term);
final TermState state;
if (termContext == null) {
// this happens with span-not query, as it doesn't include the NOT side in extractTerms()
// so we seek to the term now in this segment..., this sucks because its ugly mostly!
final Fields fields = context.reader().fields();
if (fields != null) {
final Terms terms = fields.terms(term.field());
if (terms != null) {
final TermsEnum termsEnum = terms.iterator(null);
if (termsEnum.seekExact(term.bytes(), true)) {
state = termsEnum.termState();
} else {
state = null;
}
} else {
state = null;
}
} else {
state = null;
}
} else {
state = termContext.get(context.ord);
}
if (state == null) { // term is not present in that reader
return TermSpans.EMPTY_TERM_SPANS;
}
final TermsEnum termsEnum = context.reader().terms(term.field()).iterator(null);
termsEnum.seekExact(term.bytes(), state);
final DocsAndPositionsEnum postings = termsEnum.docsAndPositions(acceptDocs, null, DocsAndPositionsEnum.FLAG_PAYLOADS);
if (postings != null) {
return new TermSpans(postings, term);
} else {
// term does exist, but has no positions
throw new IllegalStateException("field \"" + term.field() + "\" was indexed without position data; cannot run SpanTermQuery (term=" + term.text() + ")");
}
}
}