Some usecase requires more than a simple object to string translation when mapping a property to a Lucene index. To give you most of the flexibility you can also implement a bridge as a FieldBridge. This interface give you a property value and let you map it the way you want in your Lucene Document.This interface is very similar in its concept to the Hibernate™UserType.

You can for example store a given property in two different document fields

/**
 * Store the date in 3 different field year, month, day
 * to ease Range Query per year, month or day
 * (eg get all the elements of december for the last 5 years)
 *
 * @author Emmanuel Bernard
 */
public class DateSplitBridge implements FieldBridge {
    private final static TimeZone GMT = TimeZone.getTimeZone("GMT");

    public void set(String name, Object value, Document document, Field.Store store, 
    Field.Index index, Float boost) {
        Date date = (Date) value;
        Calendar cal = GregorianCalendar.getInstance( GMT );
        cal.setTime( date );
        int year = cal.get( Calendar.YEAR );
        int month = cal.get( Calendar.MONTH ) + 1;
        int day = cal.get( Calendar.DAY_OF_MONTH );
        //set year
        Field field = new Field( name + ".year", String.valueOf(year), store, index );
        if ( boost != null ) field.setBoost( boost );
        document.add( field );
        //set month and pad it if needed
        field = new Field( name + ".month", month < 10 ? "0" : "" + 
	String.valueOf(month), store, index );
        if ( boost != null ) field.setBoost( boost );
        document.add( field );
        //set day and pad it if needed
        field = new Field( name + ".day", day < 10 ? "0" : "" +
	String.valueOf(day), store, index );
        if ( boost != null ) field.setBoost( boost );
        document.add( field );
    }
}


//property@FieldBridge(impl = DateSplitBridge.class)
private Integer length;