pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / contrib / xml-query-parser / src / java / org / apache / lucene / xmlparser / builders / LikeThisQueryBuilder.java

diff --git a/lucene-java-3.5.0/lucene/contrib/xml-query-parser/src/java/org/apache/lucene/xmlparser/builders/LikeThisQueryBuilder.java b/lucene-java-3.5.0/lucene/contrib/xml-query-parser/src/java/org/apache/lucene/xmlparser/builders/LikeThisQueryBuilder.java
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+++ b/lucene-java-3.5.0/lucene/contrib/xml-query-parser/src/java/org/apache/lucene/xmlparser/builders/LikeThisQueryBuilder.java
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+/*
+ * Created on 25-Jan-2006
+ */
+package org.apache.lucene.xmlparser.builders;
+
+import java.io.IOException;
+import java.io.StringReader;
+import java.util.HashSet;
+import java.util.Set;
+
+import org.apache.lucene.analysis.Analyzer;
+import org.apache.lucene.analysis.TokenStream;
+import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
+import org.apache.lucene.search.similar.MoreLikeThisQuery;
+import org.apache.lucene.search.Query;
+import org.apache.lucene.xmlparser.DOMUtils;
+import org.apache.lucene.xmlparser.ParserException;
+import org.apache.lucene.xmlparser.QueryBuilder;
+import org.w3c.dom.Element;
+/**
+ * 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.
+ */
+
+/**
+ * 
+ */
+public class LikeThisQueryBuilder implements QueryBuilder {
+
+       private Analyzer analyzer;
+       String defaultFieldNames [];
+       int defaultMaxQueryTerms=20;
+       int defaultMinTermFrequency=1;
+       float defaultPercentTermsToMatch=30; //default is a 3rd of selected terms must match
+
+       public LikeThisQueryBuilder(Analyzer analyzer,String [] defaultFieldNames)
+       {
+               this.analyzer=analyzer;
+               this.defaultFieldNames=defaultFieldNames;
+       }
+       
+       /* (non-Javadoc)
+        * @see org.apache.lucene.xmlparser.QueryObjectBuilder#process(org.w3c.dom.Element)
+        */
+       public Query getQuery(Element e) throws ParserException {
+               String fieldsList=e.getAttribute("fieldNames"); //a comma-delimited list of fields
+               String fields[]=defaultFieldNames;
+               if((fieldsList!=null)&&(fieldsList.trim().length()>0))
+               {
+                       fields=fieldsList.trim().split(",");
+                       //trim the fieldnames
+                       for (int i = 0; i < fields.length; i++) {
+                               fields[i]=fields[i].trim();
+                       }
+               }
+               
+               //Parse any "stopWords" attribute
+               //TODO MoreLikeThis needs to ideally have per-field stopWords lists - until then 
+               //I use all analyzers/fields to generate multi-field compatible stop list
+               String stopWords=e.getAttribute("stopWords");
+               Set<String> stopWordsSet=null;
+               if((stopWords!=null)&&(fields!=null))
+               {
+                   stopWordsSet=new HashSet<String>();
+                   for (int i = 0; i < fields.length; i++)
+            {
+                try
+                {
+                  TokenStream ts = analyzer.reusableTokenStream(fields[i],new StringReader(stopWords));
+                  CharTermAttribute termAtt = ts.addAttribute(CharTermAttribute.class);
+                  ts.reset();
+                       while(ts.incrementToken()) {
+                           stopWordsSet.add(termAtt.toString());
+                       }
+                       ts.end();
+                       ts.close();
+                }
+                catch(IOException ioe)
+                {
+                    throw new ParserException("IoException parsing stop words list in "
+                            +getClass().getName()+":"+ioe.getLocalizedMessage());
+                }
+            }
+               }
+               
+               
+               MoreLikeThisQuery mlt=new MoreLikeThisQuery(DOMUtils.getText(e),fields,analyzer, fields[0]);
+               mlt.setMaxQueryTerms(DOMUtils.getAttribute(e,"maxQueryTerms",defaultMaxQueryTerms));
+               mlt.setMinTermFrequency(DOMUtils.getAttribute(e,"minTermFrequency",defaultMinTermFrequency));
+               mlt.setPercentTermsToMatch(DOMUtils.getAttribute(e,"percentTermsToMatch",defaultPercentTermsToMatch)/100);
+               mlt.setStopWords(stopWordsSet);
+               int minDocFreq=DOMUtils.getAttribute(e,"minDocFreq",-1);
+               if(minDocFreq>=0)
+               {
+                       mlt.setMinDocFreq(minDocFreq);
+               }
+
+               mlt.setBoost(DOMUtils.getAttribute(e,"boost",1.0f));
+
+               return mlt;
+       }
+
+
+
+}