Lucen query all fields

Question

I'm using Lucene 6.2.0 and trying to search over all the fields in a Document, without sending all field names. I've seen these answers, but it seems to me that these methods no longer exist in my version.

Answer 1

The top answers in the question you linked to are all still largely valid.

I would recommend you index an "äll" field with the document. This is a pretty well-known pattern (Elasticsearch does this by default, in fact). Just create a indexed, analyzed, and not stored field, and add all of the searchable fields to it as well.

doc.add(new TextField("field1", fieldContent, Field.Store.YES));
doc.add(new TextField("_all", fieldContent, Field.Store.NO));

doc.add(new TextField("field2", anotherField, Field.Store.YES));
doc.add(new TextField("_all", anotherField, Field.Store.NO));

//etc.

I noticed you've tagged solr. If you are using Solr, you can use copyFields for this.

This approach is definitely what I would recommend. It will generally provide the best search performance, as well as being easy to use. You can just make it your QueryParser default field, or use it in a simple term query, etc.

Alternatively (if you don't want to reindex, or some such), you can indeed use MultiFieldQueryParser, as long as you are able to generate the list of all the field names you want to search:

QueryParser parser = new MultiFieldQueryParser(
    new String[] {"field1", "field2" /*etc.*/}, 
    myAnalyzer);
Query query = parser.parse("the query");