Querydsl Lucene 4

The Lucene module provides integration with the Lucene 4 indexing library.

Maven integration

Add the following dependencies to your Maven project :

<dependency>
  <groupId>com.querydsl</groupId>
  <artifactId>querydsl-lucene4</artifactId>
  <version>${querydsl.version}</version>
</dependency>

<dependency>
  <groupId>org.slf4j</groupId>
  <artifactId>slf4j-log4j12</artifactId>
  <version>1.6.1</version>
</dependency>

Creating the query types

With fields year and title a manually created query type could look something like this:

public class QDocument extends EntityPathBase<Document>{
    private static final long serialVersionUID = -4872833626508344081L;
        
    public QDocument(String var) {
        super(Document.class, PathMetadataFactory.forVariable(var));
    }

    public final StringPath year = createString("year");

    public final StringPath title = createString("title");
}

QDocument represents a Lucene document with the fields year and title.

Code generation is not available for Lucene, since no schema data is available.

Querying

Querying with Querydsl Lucene is as simple as this:

QDocument doc = new QDocument("doc");

IndexSearcher searcher = new IndexSearcher(index);
LuceneQuery query = new LuceneQuery(true, searcher); 
List<Document> documents = query
    .where(doc.year.between("1800", "2000").and(doc.title.startsWith("Huckle"))
    .list();

which is transformed into the following Lucene query :

+year:[1800 TO 2000] +title:huckle*

For more information on the Querydsl Lucene module visit the reference documentation http://www.querydsl.com/static/querydsl/latest/reference/html/ch02s05.html