| /* |
| * 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.document.StringField; |
| import org.apache.lucene.index.FieldInfo; |
| import org.apache.lucene.index.FieldInfos; |
| import org.apache.lucene.index.LeafReader; |
| import org.apache.lucene.index.LeafReaderContext; |
| |
| /** |
| * A {@link Query} that matches documents that have a value for a given field |
| * as reported by field norms. This will not work for fields that omit norms, |
| * e.g. {@link StringField}. |
| */ |
| public final class NormsFieldExistsQuery extends Query { |
| |
| private final String field; |
| |
| /** Create a query that will match that have a value for the given |
| * {@code field}. */ |
| public NormsFieldExistsQuery(String field) { |
| this.field = Objects.requireNonNull(field); |
| } |
| |
| public String getField() { |
| return field; |
| } |
| |
| @Override |
| public boolean equals(Object other) { |
| return sameClassAs(other) && |
| field.equals(((NormsFieldExistsQuery) other).field); |
| } |
| |
| @Override |
| public int hashCode() { |
| return 31 * classHash() + field.hashCode(); |
| } |
| |
| @Override |
| public String toString(String field) { |
| return "NormsFieldExistsQuery [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) throws IOException { |
| return new ConstantScoreWeight(this, boost) { |
| @Override |
| public Scorer scorer(LeafReaderContext context) throws IOException { |
| FieldInfos fieldInfos = context.reader().getFieldInfos(); |
| FieldInfo fieldInfo = fieldInfos.fieldInfo(field); |
| if (fieldInfo == null || fieldInfo.hasNorms() == false) { |
| return null; |
| } |
| LeafReader reader = context.reader(); |
| DocIdSetIterator iterator = reader.getNormValues(field); |
| return new ConstantScoreScorer(this, score(), scoreMode, iterator); |
| } |
| |
| @Override |
| public boolean isCacheable(LeafReaderContext ctx) { |
| return true; |
| } |
| }; |
| } |
| } |