lucene-java-3.5.0/lucene/contrib/xml-query-parser/src/java/org/apache/lucene/xmlparser/builders/TermsQueryBuilder.java

   1 package org.apache.lucene.xmlparser.builders;
   2
   3 import java.io.IOException;
   4 import java.io.StringReader;
   5
   6 import org.apache.lucene.analysis.Analyzer;
   7 import org.apache.lucene.analysis.TokenStream;
   8 import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
   9 import org.apache.lucene.index.Term;
  10 import org.apache.lucene.search.BooleanClause;
  11 import org.apache.lucene.search.BooleanQuery;
  12 import org.apache.lucene.search.Query;
  13 import org.apache.lucene.search.TermQuery;
  14 import org.apache.lucene.xmlparser.DOMUtils;
  15 import org.apache.lucene.xmlparser.ParserException;
  16 import org.apache.lucene.xmlparser.QueryBuilder;
  17 import org.w3c.dom.Element;
  18
  19 /**
  20  * Licensed to the Apache Software Foundation (ASF) under one or more
  21  * contributor license agreements.  See the NOTICE file distributed with
  22  * this work for additional information regarding copyright ownership.
  23  * The ASF licenses this file to You under the Apache License, Version 2.0
  24  * (the "License"); you may not use this file except in compliance with
  25  * the License.  You may obtain a copy of the License at
  26  *
  27  *     http://www.apache.org/licenses/LICENSE-2.0
  28  *
  29  * Unless required by applicable law or agreed to in writing, software
  30  * distributed under the License is distributed on an "AS IS" BASIS,
  31  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  32  * See the License for the specific language governing permissions and
  33  * limitations under the License.
  34  */
  35 /**
  36  * Builds a BooleanQuery from all of the terms found in the XML element using the choice of analyzer
  37  */
  38 public class TermsQueryBuilder implements QueryBuilder {
  39
  40         Analyzer analyzer;
  41
  42
  43         public TermsQueryBuilder(Analyzer analyzer)
  44         {
  45                 this.analyzer = analyzer;
  46         }
  47
  48
  49
  50         public Query getQuery(Element e) throws ParserException {
  51
  52         String fieldName=DOMUtils.getAttributeWithInheritanceOrFail(e,"fieldName");
  53                 String text=DOMUtils.getNonBlankTextOrFail(e);
  54
  55                 BooleanQuery bq=new BooleanQuery(DOMUtils.getAttribute(e,"disableCoord",false));
  56                 bq.setMinimumNumberShouldMatch(DOMUtils.getAttribute(e,"minimumNumberShouldMatch",0));
  57                 try
  58                 {
  59             TokenStream ts = analyzer.reusableTokenStream(fieldName, new StringReader(text));
  60       CharTermAttribute termAtt = ts.addAttribute(CharTermAttribute.class);
  61                         Term term = null;
  62       ts.reset();
  63                         while (ts.incrementToken()) {
  64                                 if (term == null)
  65                                 {
  66                                         term = new Term(fieldName, termAtt.toString());
  67                                 } else
  68                                 {
  69 //                                       create from previous to save fieldName.intern overhead
  70                                         term = term.createTerm(termAtt.toString());
  71                                 }
  72                                 bq.add(new BooleanClause(new TermQuery(term),BooleanClause.Occur.SHOULD));
  73                         }
  74                         ts.end();
  75                         ts.close();
  76                 }
  77                 catch (IOException ioe)
  78                 {
  79                         throw new RuntimeException("Error constructing terms from index:"
  80                                         + ioe);
  81                 }
  82                 bq.setBoost(DOMUtils.getAttribute(e,"boost",1.0f));
  83
  84                 return bq;
  85
  86         }
  87
  88 }