/*
 * 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.lucene.search;


import java.io.IOException;
import java.util.Objects;

import org.apache.lucene.index.DocValues;
import org.apache.lucene.index.FieldInfo;
import org.apache.lucene.index.LeafReader;
import org.apache.lucene.index.LeafReaderContext;

A Query that matches documents that have a value for a given field as reported by doc values iterators.
/** * A {@link Query} that matches documents that have a value for a given field * as reported by doc values iterators. */
public final class DocValuesFieldExistsQuery extends Query { private final String field;
Create a query that will match documents which have a value for the given field.
/** Create a query that will match documents which have a value for the given * {@code field}. */
public DocValuesFieldExistsQuery(String field) { this.field = Objects.requireNonNull(field); } public String getField() { return field; } @Override public boolean equals(Object other) { return sameClassAs(other) && field.equals(((DocValuesFieldExistsQuery) other).field); } @Override public int hashCode() { return 31 * classHash() + field.hashCode(); } @Override public String toString(String field) { return "DocValuesFieldExistsQuery [field=" + this.field + "]"; } @Override public void visit(QueryVisitor visitor) { if (visitor.acceptField(field)) { visitor.visitLeaf(this); } } @Override public Weight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) { return new ConstantScoreWeight(this, boost) { @Override public Scorer scorer(LeafReaderContext context) throws IOException { DocIdSetIterator iterator = getDocValuesDocIdSetIterator(field, context.reader()); if (iterator == null) { return null; } return new ConstantScoreScorer(this, score(), scoreMode, iterator); } @Override public boolean isCacheable(LeafReaderContext ctx) { return DocValues.isCacheable(ctx, field); } }; }
Returns a DocIdSetIterator from the given field or null if the field doesn't exist in the reader or if the reader has no doc values for the field.
/** * Returns a {@link DocIdSetIterator} from the given field or null if the field doesn't exist * in the reader or if the reader has no doc values for the field. */
public static DocIdSetIterator getDocValuesDocIdSetIterator(String field, LeafReader reader) throws IOException { FieldInfo fieldInfo = reader.getFieldInfos().fieldInfo(field); final DocIdSetIterator iterator; if (fieldInfo != null) { switch (fieldInfo.getDocValuesType()) { case NONE: iterator = null; break; case NUMERIC: iterator = reader.getNumericDocValues(field); break; case BINARY: iterator = reader.getBinaryDocValues(field); break; case SORTED: iterator = reader.getSortedDocValues(field); break; case SORTED_NUMERIC: iterator = reader.getSortedNumericDocValues(field); break; case SORTED_SET: iterator = reader.getSortedSetDocValues(field); break; default: throw new AssertionError(); } return iterator; } return null; } }