Geomodel Geocell Query Engine for Objectify

ObjectifyGeocellQueryEngine.java

import java.util.List;
import java.util.StringTokenizer;

import com.beoui.geocell.GeocellQueryEngine;
import com.beoui.geocell.model.GeocellQuery;
import com.googlecode.objectify.Objectify;
import com.googlecode.objectify.Query;

/**
 * Objectify implementation for GeocellQueryEngine.
 * <p>
 * Example:
 * 
 * <pre>
 * // paramList contains values for each filter() condition 
 * List&lt;Object&gt; paramList = new ArrayList&lt;Object&gt;(); 
 * paramList.add(q); 
 * paramList.add(q + "\uFFFD"); 
 * 
 * // comma separated filter() conditions 
 * GeocellQuery baseQuery = new GeocellQuery("title &gt;=, title 
 * &lt;", paramList); 
 * GeocellQueryEngine queryEngine = new 
 * ObjectifyGeocellQueryEngine(ofy()); 
 * 
 * // perform search 
 * GeocellManager.proximitySearch( 
 *      new Point(lat, lng), maxResults, maxDistance, 
 *      MyEntity.class, 
 *      baseQuery, queryEngine, 
 * GeocellManager.MAX_GEOCELL_RESOLUTION);
 * </pre>
 */
public class ObjectifyGeocellQueryEngine implements GeocellQueryEngine {
	private String geocellsProperty;
	private Objectify ofy;
	public static final String DEFAULT_GEOCELLS_PROPERTY = "geocells";

	public ObjectifyGeocellQueryEngine(Objectify ofy) {
		this(ofy, DEFAULT_GEOCELLS_PROPERTY);
	}

	public ObjectifyGeocellQueryEngine(Objectify ofy, String geocellsProperty) {
		this.ofy = ofy;
		this.geocellsProperty = geocellsProperty;
	}

	@Override
	public <T> List<T> query(GeocellQuery baseQuery, List<String> geocells, Class<T> entityClass) {
		StringTokenizer st;
		int tokenNo = 0;
		Query<T> query = ofy.query(entityClass);
		if (baseQuery != null) {
			st = new StringTokenizer(baseQuery.getBaseQuery(), ",");
			while (st.hasMoreTokens()) {
				query.filter(st.nextToken(), baseQuery.getParameters().get(tokenNo++));
			}
		}
		return query.filter(geocellsProperty + " IN", geocells).list();
	}
}