- Lucene is a text search engine library written in Java. In a Lucene query, the query is broken up into terms and operators. There are two types of terms: Single Terms and Phrases. A Single Term is a single word such as "test" or "hello". A Phrase is a group of words surrounded by double quotes such as "hello dolly". Lucene supports fielded data (as the literature records are). When performing a search you can either specify a field, or use the default field.