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/*
 * COPIED FROM APACHE LUCENE 4.7.2
 *
 * Git URL: [email protected]:apache/lucene.git, tag: releases/lucene-solr/4.7.2, path: lucene/core/src/java
 *
 * (see https://issues.apache.org/jira/browse/OAK-10786 for details)
 */

package org.apache.lucene.util;

/*
 * 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.ArrayList;
import java.util.List;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.CachingTokenFilter;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.tokenattributes.PositionIncrementAttribute;
import org.apache.lucene.analysis.tokenattributes.TermToBytesRefAttribute;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.MultiPhraseQuery;
import org.apache.lucene.search.PhraseQuery;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.TermQuery;

/**
 * Creates queries from the {@link Analyzer} chain.
 * 

* Example usage: *

 *   QueryBuilder builder = new QueryBuilder(analyzer);
 *   Query a = builder.createBooleanQuery("body", "just a test");
 *   Query b = builder.createPhraseQuery("body", "another test");
 *   Query c = builder.createMinShouldMatchQuery("body", "another test", 0.5f);
 * 
*

* This can also be used as a subclass for query parsers to make it easier * to interact with the analysis chain. Factory methods such as {@code newTermQuery} * are provided so that the generated queries can be customized. */ public class QueryBuilder { private Analyzer analyzer; private boolean enablePositionIncrements = true; /** Creates a new QueryBuilder using the given analyzer. */ public QueryBuilder(Analyzer analyzer) { this.analyzer = analyzer; } /** * Creates a boolean query from the query text. *

* This is equivalent to {@code createBooleanQuery(field, queryText, Occur.SHOULD)} * @param field field name * @param queryText text to be passed to the analyzer * @return {@code TermQuery} or {@code BooleanQuery}, based on the analysis * of {@code queryText} */ public Query createBooleanQuery(String field, String queryText) { return createBooleanQuery(field, queryText, BooleanClause.Occur.SHOULD); } /** * Creates a boolean query from the query text. *

* @param field field name * @param queryText text to be passed to the analyzer * @param operator operator used for clauses between analyzer tokens. * @return {@code TermQuery} or {@code BooleanQuery}, based on the analysis * of {@code queryText} */ public Query createBooleanQuery(String field, String queryText, BooleanClause.Occur operator) { if (operator != BooleanClause.Occur.SHOULD && operator != BooleanClause.Occur.MUST) { throw new IllegalArgumentException("invalid operator: only SHOULD or MUST are allowed"); } return createFieldQuery(analyzer, operator, field, queryText, false, 0); } /** * Creates a phrase query from the query text. *

* This is equivalent to {@code createPhraseQuery(field, queryText, 0)} * @param field field name * @param queryText text to be passed to the analyzer * @return {@code TermQuery}, {@code BooleanQuery}, {@code PhraseQuery}, or * {@code MultiPhraseQuery}, based on the analysis of {@code queryText} */ public Query createPhraseQuery(String field, String queryText) { return createPhraseQuery(field, queryText, 0); } /** * Creates a phrase query from the query text. *

* @param field field name * @param queryText text to be passed to the analyzer * @param phraseSlop number of other words permitted between words in query phrase * @return {@code TermQuery}, {@code BooleanQuery}, {@code PhraseQuery}, or * {@code MultiPhraseQuery}, based on the analysis of {@code queryText} */ public Query createPhraseQuery(String field, String queryText, int phraseSlop) { return createFieldQuery(analyzer, BooleanClause.Occur.MUST, field, queryText, true, phraseSlop); } /** * Creates a minimum-should-match query from the query text. *

* @param field field name * @param queryText text to be passed to the analyzer * @param fraction of query terms {@code [0..1]} that should match * @return {@code TermQuery} or {@code BooleanQuery}, based on the analysis * of {@code queryText} */ public Query createMinShouldMatchQuery(String field, String queryText, float fraction) { if (Float.isNaN(fraction) || fraction < 0 || fraction > 1) { throw new IllegalArgumentException("fraction should be >= 0 and <= 1"); } // TODO: wierd that BQ equals/rewrite/scorer doesn't handle this? if (fraction == 1) { return createBooleanQuery(field, queryText, BooleanClause.Occur.MUST); } Query query = createFieldQuery(analyzer, BooleanClause.Occur.SHOULD, field, queryText, false, 0); if (query instanceof BooleanQuery) { BooleanQuery bq = (BooleanQuery) query; bq.setMinimumNumberShouldMatch((int) (fraction * bq.clauses().size())); } return query; } /** * Returns the analyzer. * @see #setAnalyzer(Analyzer) */ public Analyzer getAnalyzer() { return analyzer; } /** * Sets the analyzer used to tokenize text. */ public void setAnalyzer(Analyzer analyzer) { this.analyzer = analyzer; } /** * Returns true if position increments are enabled. * @see #setEnablePositionIncrements(boolean) */ public boolean getEnablePositionIncrements() { return enablePositionIncrements; } /** * Set to true to enable position increments in result query. *

* When set, result phrase and multi-phrase queries will * be aware of position increments. * Useful when e.g. a StopFilter increases the position increment of * the token that follows an omitted token. *

* Default: true. */ public void setEnablePositionIncrements(boolean enable) { this.enablePositionIncrements = enable; } /** * Creates a query from the analysis chain. *

* Expert: this is more useful for subclasses such as queryparsers. * If using this class directly, just use {@link #createBooleanQuery(String, String)} * and {@link #createPhraseQuery(String, String)} * @param analyzer analyzer used for this query * @param operator default boolean operator used for this query * @param field field to create queries against * @param queryText text to be passed to the analysis chain * @param quoted true if phrases should be generated when terms occur at more than one position * @param phraseSlop slop factor for phrase/multiphrase queries */ protected final Query createFieldQuery(Analyzer analyzer, BooleanClause.Occur operator, String field, String queryText, boolean quoted, int phraseSlop) { assert operator == BooleanClause.Occur.SHOULD || operator == BooleanClause.Occur.MUST; // Use the analyzer to get all the tokens, and then build a TermQuery, // PhraseQuery, or nothing based on the term count CachingTokenFilter buffer = null; TermToBytesRefAttribute termAtt = null; PositionIncrementAttribute posIncrAtt = null; int numTokens = 0; int positionCount = 0; boolean severalTokensAtSamePosition = false; boolean hasMoreTokens = false; TokenStream source = null; try { source = analyzer.tokenStream(field, queryText); source.reset(); buffer = new CachingTokenFilter(source); buffer.reset(); if (buffer.hasAttribute(TermToBytesRefAttribute.class)) { termAtt = buffer.getAttribute(TermToBytesRefAttribute.class); } if (buffer.hasAttribute(PositionIncrementAttribute.class)) { posIncrAtt = buffer.getAttribute(PositionIncrementAttribute.class); } if (termAtt != null) { try { hasMoreTokens = buffer.incrementToken(); while (hasMoreTokens) { numTokens++; int positionIncrement = (posIncrAtt != null) ? posIncrAtt.getPositionIncrement() : 1; if (positionIncrement != 0) { positionCount += positionIncrement; } else { severalTokensAtSamePosition = true; } hasMoreTokens = buffer.incrementToken(); } } catch (IOException e) { // ignore } } } catch (IOException e) { throw new RuntimeException("Error analyzing query text", e); } finally { IOUtils.closeWhileHandlingException(source); } // rewind the buffer stream buffer.reset(); BytesRef bytes = termAtt == null ? null : termAtt.getBytesRef(); if (numTokens == 0) return null; else if (numTokens == 1) { try { boolean hasNext = buffer.incrementToken(); assert hasNext == true; termAtt.fillBytesRef(); } catch (IOException e) { // safe to ignore, because we know the number of tokens } return newTermQuery(new Term(field, BytesRef.deepCopyOf(bytes))); } else { if (severalTokensAtSamePosition || (!quoted)) { if (positionCount == 1 || (!quoted)) { // no phrase query: if (positionCount == 1) { // simple case: only one position, with synonyms BooleanQuery q = newBooleanQuery(true); for (int i = 0; i < numTokens; i++) { try { boolean hasNext = buffer.incrementToken(); assert hasNext == true; termAtt.fillBytesRef(); } catch (IOException e) { // safe to ignore, because we know the number of tokens } Query currentQuery = newTermQuery( new Term(field, BytesRef.deepCopyOf(bytes))); q.add(currentQuery, BooleanClause.Occur.SHOULD); } return q; } else { // multiple positions BooleanQuery q = newBooleanQuery(false); Query currentQuery = null; for (int i = 0; i < numTokens; i++) { try { boolean hasNext = buffer.incrementToken(); assert hasNext == true; termAtt.fillBytesRef(); } catch (IOException e) { // safe to ignore, because we know the number of tokens } if (posIncrAtt != null && posIncrAtt.getPositionIncrement() == 0) { if (!(currentQuery instanceof BooleanQuery)) { Query t = currentQuery; currentQuery = newBooleanQuery(true); ((BooleanQuery)currentQuery).add(t, BooleanClause.Occur.SHOULD); } ((BooleanQuery)currentQuery).add(newTermQuery(new Term(field, BytesRef.deepCopyOf(bytes))), BooleanClause.Occur.SHOULD); } else { if (currentQuery != null) { q.add(currentQuery, operator); } currentQuery = newTermQuery(new Term(field, BytesRef.deepCopyOf(bytes))); } } q.add(currentQuery, operator); return q; } } else { // phrase query: MultiPhraseQuery mpq = newMultiPhraseQuery(); mpq.setSlop(phraseSlop); List multiTerms = new ArrayList(); int position = -1; for (int i = 0; i < numTokens; i++) { int positionIncrement = 1; try { boolean hasNext = buffer.incrementToken(); assert hasNext == true; termAtt.fillBytesRef(); if (posIncrAtt != null) { positionIncrement = posIncrAtt.getPositionIncrement(); } } catch (IOException e) { // safe to ignore, because we know the number of tokens } if (positionIncrement > 0 && multiTerms.size() > 0) { if (enablePositionIncrements) { mpq.add(multiTerms.toArray(new Term[0]),position); } else { mpq.add(multiTerms.toArray(new Term[0])); } multiTerms.clear(); } position += positionIncrement; multiTerms.add(new Term(field, BytesRef.deepCopyOf(bytes))); } if (enablePositionIncrements) { mpq.add(multiTerms.toArray(new Term[0]),position); } else { mpq.add(multiTerms.toArray(new Term[0])); } return mpq; } } else { PhraseQuery pq = newPhraseQuery(); pq.setSlop(phraseSlop); int position = -1; for (int i = 0; i < numTokens; i++) { int positionIncrement = 1; try { boolean hasNext = buffer.incrementToken(); assert hasNext == true; termAtt.fillBytesRef(); if (posIncrAtt != null) { positionIncrement = posIncrAtt.getPositionIncrement(); } } catch (IOException e) { // safe to ignore, because we know the number of tokens } if (enablePositionIncrements) { position += positionIncrement; pq.add(new Term(field, BytesRef.deepCopyOf(bytes)),position); } else { pq.add(new Term(field, BytesRef.deepCopyOf(bytes))); } } return pq; } } } /** * Builds a new BooleanQuery instance. *

* This is intended for subclasses that wish to customize the generated queries. * @param disableCoord disable coord * @return new BooleanQuery instance */ protected BooleanQuery newBooleanQuery(boolean disableCoord) { return new BooleanQuery(disableCoord); } /** * Builds a new TermQuery instance. *

* This is intended for subclasses that wish to customize the generated queries. * @param term term * @return new TermQuery instance */ protected Query newTermQuery(Term term) { return new TermQuery(term); } /** * Builds a new PhraseQuery instance. *

* This is intended for subclasses that wish to customize the generated queries. * @return new PhraseQuery instance */ protected PhraseQuery newPhraseQuery() { return new PhraseQuery(); } /** * Builds a new MultiPhraseQuery instance. *

* This is intended for subclasses that wish to customize the generated queries. * @return new MultiPhraseQuery instance */ protected MultiPhraseQuery newMultiPhraseQuery() { return new MultiPhraseQuery(); } }





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