package org.apache.lucene.xmlparser.builders;
import java.io.IOException;
import java.io.StringReader;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.Token;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.Filter;
import org.apache.lucene.search.TermsFilter;
import org.apache.lucene.xmlparser.DOMUtils;
import org.apache.lucene.xmlparser.FilterBuilder;
import org.apache.lucene.xmlparser.ParserException;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
/**
* @author maharwood
*
* @
*/
public class TermsFilterBuilder implements FilterBuilder
{
Analyzer analyzer;
/**
* @param analyzer
*/
public TermsFilterBuilder(Analyzer analyzer)
{
this.analyzer = analyzer;
}
/* (non-Javadoc)
* @see org.apache.lucene.xmlparser.FilterBuilder#process(org.w3c.dom.Element)
*/
public Filter getFilter(Element e) throws ParserException
{
TermsFilter tf=new TermsFilter();
NodeList nl = e.getElementsByTagName("Field");
for(int i=0;i<nl.getLength();i++)
{
Element fieldElem=(Element) nl.item(i);
String fieldName=DOMUtils.getAttributeWithInheritance(fieldElem,"fieldName");
if(fieldName==null)
{
throw new ParserException("TermsFilter missing \"fieldName\" element");
}
String text=DOMUtils.getText(fieldElem).trim();
TokenStream ts = analyzer.tokenStream(fieldName, new StringReader(text));
try
{
Token token=ts.next();
Term term=null;
while(token!=null)
{
if(term==null)
{
term=new Term(fieldName,token.termText());
}
else
{
term=term.createTerm(token.termText()); //create from previous to save fieldName.intern overhead
}
tf.addTerm(term);
token=ts.next();
}
}
catch(IOException ioe)
{
throw new RuntimeException("Error constructing terms from index:"+ioe);
}
}
return tf;
}
}