How do I sort Lucene results by field value using a HitCollector?

Question

I'm using the following code to execute a query in Lucene.Net

var collector = new GroupingHitCollector(searcher.GetIndexReader());
searcher.Search(myQuery, collector);
resultsCount = collector.Hits.Count;

How do I sort these search results based on a field?

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Update

Thanks for your answer. I had tried using TopFieldDocCollector but I got an error saying, "value is too small or too large" when i passed 5000 as numHits argument value. Please suggest a valid value to pass.

Answer 1

The search.Searcher.search method will accept a search.Sort parameter, which can be constructed as simply as:

new Sort("my_sort_field")

However, there are some limitations on which fields can be sorted on - they need to be indexed but not tokenized, and the values convertible to Strings, Floats or Integers.

Lucene in Action covers all of the details, as well as sorting my multiple fields and so on.

Answer 2

thanks for your input,but I need to use collector object(instead of using hits) and I dont see any overloaded Searcher.search method which returns a collector object as well as sort it on a field.

Answer 3

What you're looking for is probably TopFieldDocCollector. Use it instead of the GroupingHitCollector (what is that?), or inside it.

Comment on this if you need more info. I'll be happy to help.

Answer 4

thanks for your answer......... I had tried using TopFieldDocCollector but i got an error saying "value is too small or too large" when i passed 5000 as numHits argument value...please suggest a valid value to pass...

Thanks.