+++ /dev/null
-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 java.io.IOException;
-import java.util.Set;
-
-import org.apache.lucene.index.IndexReader;
-import org.apache.lucene.index.Term;
-import org.apache.lucene.search.Query;
-import org.apache.lucene.search.Weight;
-import org.apache.lucene.search.Searcher;
-import org.apache.lucene.search.Similarity;
-import org.apache.lucene.util.ToStringUtils;
-
-/**
- * <p>Wrapper to allow {@link SpanQuery} objects participate in composite
- * single-field SpanQueries by 'lying' about their search field. That is,
- * the masked SpanQuery will function as normal,
- * but {@link SpanQuery#getField()} simply hands back the value supplied
- * in this class's constructor.</p>
- *
- * <p>This can be used to support Queries like {@link SpanNearQuery} or
- * {@link SpanOrQuery} across different fields, which is not ordinarily
- * permitted.</p>
- *
- * <p>This can be useful for denormalized relational data: for example, when
- * indexing a document with conceptually many 'children': </p>
- *
- * <pre>
- * teacherid: 1
- * studentfirstname: james
- * studentsurname: jones
- *
- * teacherid: 2
- * studenfirstname: james
- * studentsurname: smith
- * studentfirstname: sally
- * studentsurname: jones
- * </pre>
- *
- * <p>a SpanNearQuery with a slop of 0 can be applied across two
- * {@link SpanTermQuery} objects as follows:
- * <pre>
- * SpanQuery q1 = new SpanTermQuery(new Term("studentfirstname", "james"));
- * SpanQuery q2 = new SpanTermQuery(new Term("studentsurname", "jones"));
- * SpanQuery q2m = new FieldMaskingSpanQuery(q2, "studentfirstname");
- * Query q = new SpanNearQuery(new SpanQuery[]{q1, q2m}, -1, false);
- * </pre>
- * to search for 'studentfirstname:james studentsurname:jones' and find
- * teacherid 1 without matching teacherid 2 (which has a 'james' in position 0
- * and 'jones' in position 1). </p>
- *
- * <p>Note: as {@link #getField()} returns the masked field, scoring will be
- * done using the norms of the field name supplied. This may lead to unexpected
- * scoring behaviour.</p>
- */
-public class FieldMaskingSpanQuery extends SpanQuery {
- private SpanQuery maskedQuery;
- private String field;
-
- public FieldMaskingSpanQuery(SpanQuery maskedQuery, String maskedField) {
- this.maskedQuery = maskedQuery;
- this.field = maskedField;
- }
-
- @Override
- public String getField() {
- return field;
- }
-
- public SpanQuery getMaskedQuery() {
- return maskedQuery;
- }
-
- // :NOTE: getBoost and setBoost are not proxied to the maskedQuery
- // ...this is done to be more consistent with things like SpanFirstQuery
-
- @Override
- public Spans getSpans(IndexReader reader) throws IOException {
- return maskedQuery.getSpans(reader);
- }
-
- @Override
- public void extractTerms(Set<Term> terms) {
- maskedQuery.extractTerms(terms);
- }
-
- @Override
- public Weight createWeight(Searcher searcher) throws IOException {
- return maskedQuery.createWeight(searcher);
- }
-
- @Override
- public Query rewrite(IndexReader reader) throws IOException {
- FieldMaskingSpanQuery clone = null;
-
- SpanQuery rewritten = (SpanQuery) maskedQuery.rewrite(reader);
- if (rewritten != maskedQuery) {
- clone = (FieldMaskingSpanQuery) this.clone();
- clone.maskedQuery = rewritten;
- }
-
- if (clone != null) {
- return clone;
- } else {
- return this;
- }
- }
-
- @Override
- public String toString(String field) {
- StringBuilder buffer = new StringBuilder();
- buffer.append("mask(");
- buffer.append(maskedQuery.toString(field));
- buffer.append(")");
- buffer.append(ToStringUtils.boost(getBoost()));
- buffer.append(" as ");
- buffer.append(this.field);
- return buffer.toString();
- }
-
- @Override
- public boolean equals(Object o) {
- if (!(o instanceof FieldMaskingSpanQuery))
- return false;
- FieldMaskingSpanQuery other = (FieldMaskingSpanQuery) o;
- return (this.getField().equals(other.getField())
- && (this.getBoost() == other.getBoost())
- && this.getMaskedQuery().equals(other.getMaskedQuery()));
-
- }
-
- @Override
- public int hashCode() {
- return getMaskedQuery().hashCode()
- ^ getField().hashCode()
- ^ Float.floatToRawIntBits(getBoost());
- }
-}
fnp / pylucene.git / blobdiff