Works in conjunction with the SinkTokenizer to provide the ability to set aside tokens that have already been analyzed. This is useful in situations where multiple fields share many common analysis steps and then go their separate ways.

It is also useful for doing things like entity extraction or proper noun analysis as part of the analysis workflow and saving off those tokens for use in another field.

            SinkTokenizer sink1 = new SinkTokenizer();
            SinkTokenizer sink2 = new SinkTokenizer();
            TokenStream source1 = new TeeTokenFilter(new TeeTokenFilter(new WhitespaceTokenizer(reader1), sink1), sink2);
            TokenStream source2 = new TeeTokenFilter(new TeeTokenFilter(new WhitespaceTokenizer(reader2), sink1), sink2);
            TokenStream final1 = new LowerCaseFilter(source1);
            TokenStream final2 = source2;
            TokenStream final3 = new EntityDetect(sink1);
            TokenStream final4 = new URLDetect(sink2);
            d.add(new Field("f1", final1));
            d.add(new Field("f2", final2));
            d.add(new Field("f3", final3));
            d.add(new Field("f4", final4));
            

In this example,

CopyC#

sink1

and

CopyC#

sink2

will both get tokens from both

CopyC#

reader1

and

CopyC#

reader2

after whitespace tokenizer and now we can further wrap any of these in extra analysis, and more "sources" can be inserted if desired. It is important, that tees are consumed before sinks (in the above example, the field names must be less the sink's field names). Note, the EntityDetect and URLDetect TokenStreams are for the example and do not currently exist in Lucene

See LUCENE-1058.

WARNING: {@link TeeTokenFilter} and {@link SinkTokenizer} only work with the old TokenStream API. If you switch to the new API, you need to use {@link TeeSinkTokenFilter} instead, which offers the same functionality.

[ObsoleteAttribute("Use TeeSinkTokenFilter instead")]
public class TeeTokenFilter : TokenFilter

<ObsoleteAttribute("Use TeeSinkTokenFilter instead")> _
Public Class TeeTokenFilter _
	Inherits TokenFilter

[ObsoleteAttribute(L"Use TeeSinkTokenFilter instead")]
public ref class TeeTokenFilter : public TokenFilter