| package org.apache.lucene.search; |
| |
| /* |
| * 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.util.Objects; |
| |
| /** A clause in a BooleanQuery. */ |
| public final class BooleanClause { |
| |
| /** Specifies how clauses are to occur in matching documents. */ |
| public static enum Occur { |
| |
| /** Use this operator for clauses that <i>must</i> appear in the matching documents. */ |
| MUST { @Override public String toString() { return "+"; } }, |
| |
| /** Like {@link #MUST} except that these clauses do not participate in scoring. */ |
| FILTER { @Override public String toString() { return "#"; } }, |
| |
| /** Use this operator for clauses that <i>should</i> appear in the |
| * matching documents. For a BooleanQuery with no <code>MUST</code> |
| * clauses one or more <code>SHOULD</code> clauses must match a document |
| * for the BooleanQuery to match. |
| * @see BooleanQuery.Builder#setMinimumNumberShouldMatch |
| */ |
| SHOULD { @Override public String toString() { return ""; } }, |
| |
| /** Use this operator for clauses that <i>must not</i> appear in the matching documents. |
| * Note that it is not possible to search for queries that only consist |
| * of a <code>MUST_NOT</code> clause. These clauses do not contribute to the |
| * score of documents. */ |
| MUST_NOT { @Override public String toString() { return "-"; } }; |
| |
| } |
| |
| /** The query whose matching documents are combined by the boolean query. |
| */ |
| private Query query; |
| |
| private Occur occur; |
| |
| |
| /** Constructs a BooleanClause. |
| */ |
| public BooleanClause(Query query, Occur occur) { |
| this.query = Objects.requireNonNull(query, "Query must not be null"); |
| this.occur = Objects.requireNonNull(occur, "Occur must not be null"); |
| |
| } |
| |
| public Occur getOccur() { |
| return occur; |
| } |
| |
| public Query getQuery() { |
| return query; |
| } |
| |
| public boolean isProhibited() { |
| return Occur.MUST_NOT == occur; |
| } |
| |
| public boolean isRequired() { |
| return occur == Occur.MUST || occur == Occur.FILTER; |
| } |
| |
| public boolean isScoring() { |
| return occur == Occur.MUST || occur == Occur.SHOULD; |
| } |
| |
| /** Returns true if <code>o</code> is equal to this. */ |
| @Override |
| public boolean equals(Object o) { |
| if (o == null || !(o instanceof BooleanClause)) |
| return false; |
| BooleanClause other = (BooleanClause)o; |
| return this.query.equals(other.query) |
| && this.occur == other.occur; |
| } |
| |
| /** Returns a hash code value for this object.*/ |
| @Override |
| public int hashCode() { |
| return 31 * query.hashCode() + occur.hashCode(); |
| } |
| |
| |
| @Override |
| public String toString() { |
| return occur.toString() + query.toString(); |
| } |
| |
| /** |
| * Set the {@link Occur}. |
| * @deprecated BooleanClause will be immutable in 6.0. |
| */ |
| @Deprecated |
| public void setOccur(Occur occur) { |
| this.occur = Objects.requireNonNull(occur, "Occur must not be null"); |
| } |
| |
| /** |
| * Set the {@link Query}. |
| * @deprecated BooleanClause will be immutable in 6.0. |
| */ |
| @Deprecated |
| public void setQuery(Query query) { |
| this.query = Objects.requireNonNull(query, "Query must not be null"); |
| } |
| } |