Looks to me like your looking for Kelvin Tan's chainable filter
http://www.mail-archive.com/lucene-user@jakarta.apache.org/msg01168.html Dan
-----Original Message-----
From: Christian Meunier [mailto:vchris@club-internet.fr]
Sent: Friday, May 24, 2002 5:38 AM
To: Lucene Users List
Subject: Re: Few questions regarding the design of the Filter class
>
> A workaround for what? It's not clear what you're trying to do.
>
Here is what i am trying to do:
A simple class to filter a field
FieldFilter.java
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import java.util.BitSet;
import java.io.IOException;
import org.apache.lucene.index.Term;
import org.apache.lucene.index.TermDocs;
import org.apache.lucene.index.IndexReader;
public class FieldFilter extends org.apache.lucene.search.Filter
{
private String field;
private String value;
private Term searchTerm;
public FieldFilter(String field, String value)
{
this.field = field;
this.value = value;
searchTerm = new Term(field, value);
}
public String getField()
{
return field;
}
public BitSet bits(IndexReader reader) throws IOException
{
BitSet bits = new BitSet(reader.maxDoc());
TermDocs matchingDocs = reader.termDocs(searchTerm);
try
{
while(matchingDocs.next())
{
bits.set(matchingDocs.doc());
}
}
catch (Exception e) { /* ignore */ }
finally
{
if (matchingDocs != null)
{
matchingDocs.close();
}
}
return bits;
}
}
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I then coded a class which handle multiple filters (FieldFilter,
DateFilter,....) at once
MultiFilter.java
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import java.util.Hashtable;
import java.util.BitSet;
import java.util.ArrayList;
import java.io.IOException;
import org.apache.lucene.index.Term;
import org.apache.lucene.index.TermDocs;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.search.Filter;
public class MultiFilter extends org.apache.lucene.search.Filter
{
private ArrayList filterList;
public MultiFilter()
{
filterList = new ArrayList();
}
public MultiFilter(int initialCapacity)
{
filterList = new ArrayList(initialCapacity);
}
public String getField()
{
return null;
}
public void add(Filter filter)
{
filterList.add(filter);
}
public BitSet bits(IndexReader reader) throws IOException
{
int filterListSize = filterList.size();
if (filterListSize > 0)
{
Hashtable filters = new Hashtable();
int pos=0;
for (int i=0; i<filterListSize; i++)
{
if(!filters.containsKey( ((Filter)filterList.get(i)).getField()))
{
filters.put(((Filter)filterList.get(i)).getField(),""+pos);
pos++;
}
}
BitSet [] tab_bits = new BitSet[filters.size()];
for (int i=0; i<filterListSize; i++)
{
if(tab_bits[Integer.parseInt((String)filters.get(((Filter)filterList.get(i))
.getField()))]==null)
tab_bits[Integer.parseInt((String)filters.get(((Filter)filterList.get(i)).ge
tField()))] = ((Filter)filterList.get(i)).bits(reader);
else
tab_bits[Integer.parseInt((String)filters.get(((Filter)filterList.get(i)).ge
tField()))].or(((Filter)filterList.get(i)).bits(reader));
}
for(int i=1;i<tab_bits.length;i++)
tab_bits[0].and(tab_bits[i]);
return tab_bits[0];
}
else
{
return new BitSet(reader.maxDoc());
}
}
}
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As you can see, it's mandatory that the Filter class specify a getFilter
method so such MultiFilter can work.
> Doug
>
Best regards
Christian
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