| package org.apache.lucene.search; |
| |
| /* ==================================================================== |
| * The Apache Software License, Version 1.1 |
| * |
| * Copyright (c) 2001 The Apache Software Foundation. All rights |
| * reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. The end-user documentation included with the redistribution, |
| * if any, must include the following acknowledgment: |
| * "This product includes software developed by the |
| * Apache Software Foundation (http://www.apache.org/)." |
| * Alternately, this acknowledgment may appear in the software itself, |
| * if and wherever such third-party acknowledgments normally appear. |
| * |
| * 4. The names "Apache" and "Apache Software Foundation" and |
| * "Apache Lucene" must not be used to endorse or promote products |
| * derived from this software without prior written permission. For |
| * written permission, please contact apache@apache.org. |
| * |
| * 5. Products derived from this software may not be called "Apache", |
| * "Apache Lucene", nor may "Apache" appear in their name, without |
| * prior written permission of the Apache Software Foundation. |
| * |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
| * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| */ |
| |
| import java.io.IOException; |
| import java.util.Vector; |
| import org.apache.lucene.index.IndexReader; |
| |
| /** A Query that matches documents matching boolean combinations of other |
| queries, typically {@link TermQuery}s or {@link PhraseQuery}s. |
| */ |
| final public class BooleanQuery extends Query { |
| private Vector clauses = new Vector(); |
| |
| /** Constructs an empty boolean query. */ |
| public BooleanQuery() {} |
| |
| /** Adds a clause to a boolean query. Clauses may be: |
| <ul> |
| <li><code>required</code> which means that documents which <i>do not</i> |
| match this sub-query will <it>not</it> match the boolean query; |
| <li><code>prohibited</code> which means that documents which <i>do</i> |
| match this sub-query will <it>not</it> match the boolean query; or |
| <li>neither, in which case matched documents are neither prohibited from |
| nor required to match the sub-query. |
| </ul> |
| It is an error to specify a clause as both <code>required</code> and |
| <code>prohibited</code>. |
| */ |
| public final void add(Query query, boolean required, boolean prohibited) { |
| clauses.addElement(new BooleanClause(query, required, prohibited)); |
| } |
| |
| /** Adds a clause to a boolean query. */ |
| public final void add(BooleanClause clause) { |
| clauses.addElement(clause); |
| } |
| |
| void prepare(IndexReader reader) { |
| for (int i = 0 ; i < clauses.size(); i++) { |
| BooleanClause c = (BooleanClause)clauses.elementAt(i); |
| c.query.prepare(reader); |
| } |
| } |
| |
| final float sumOfSquaredWeights(Searcher searcher) |
| throws IOException { |
| float sum = 0.0f; |
| |
| for (int i = 0 ; i < clauses.size(); i++) { |
| BooleanClause c = (BooleanClause)clauses.elementAt(i); |
| if (!c.prohibited) |
| sum += c.query.sumOfSquaredWeights(searcher); // sum sub-query weights |
| } |
| |
| return sum; |
| } |
| |
| final void normalize(float norm) { |
| for (int i = 0 ; i < clauses.size(); i++) { |
| BooleanClause c = (BooleanClause)clauses.elementAt(i); |
| if (!c.prohibited) |
| c.query.normalize(norm); |
| } |
| } |
| |
| final Scorer scorer(IndexReader reader) |
| throws IOException { |
| |
| if (clauses.size() == 1) { // optimize 1-term queries |
| BooleanClause c = (BooleanClause)clauses.elementAt(0); |
| if (!c.prohibited) // just return term scorer |
| return c.query.scorer(reader); |
| } |
| |
| BooleanScorer result = new BooleanScorer(); |
| |
| int theMask = 1, thisMask; |
| for (int i = 0 ; i < clauses.size(); i++) { |
| BooleanClause c = (BooleanClause)clauses.elementAt(i); |
| if (c.required || c.prohibited) { |
| thisMask = theMask; |
| theMask = theMask << 1; |
| } else |
| thisMask = 0; |
| |
| Scorer subScorer = c.query.scorer(reader); |
| if (subScorer != null) |
| result.add(subScorer, c.required, c.prohibited); |
| else if (c.required) |
| return null; |
| } |
| if (theMask == 0) |
| throw new IndexOutOfBoundsException |
| ("More than 32 required/prohibited clauses in query."); |
| |
| return result; |
| } |
| |
| /** Prints a user-readable version of this query. */ |
| public String toString(String field) { |
| StringBuffer buffer = new StringBuffer(); |
| for (int i = 0 ; i < clauses.size(); i++) { |
| BooleanClause c = (BooleanClause)clauses.elementAt(i); |
| if (c.prohibited) |
| buffer.append("-"); |
| else if (c.required) |
| buffer.append("+"); |
| |
| Query subQuery = c.query; |
| if (subQuery instanceof BooleanQuery) { // wrap sub-bools in parens |
| BooleanQuery bq = (BooleanQuery)subQuery; |
| buffer.append("("); |
| buffer.append(c.query.toString(field)); |
| buffer.append(")"); |
| } else |
| buffer.append(c.query.toString(field)); |
| |
| if (i != clauses.size()-1) |
| buffer.append(" "); |
| } |
| return buffer.toString(); |
| } |
| |
| } |