gistfile1.java

import com.mongodb.*;
import org.bson.BSON;

import java.util.regex.Pattern;

/**
 * @author trnl
 *         Date: 12/27/11
 *         Time: 3:49 PM
 */
public class Tester {

    public static void main(String[] args) throws Exception, InterruptedException {
        DBCollection c = new Mongo().getDB("tmp").getCollection("tmp");
        
        c.drop();

        c.insert(o("a","aaa"));
        c.insert(o("a", "aab"));
        c.insert(o("a", "abb"));

        System.out.println(c.find(o("a", Pattern.compile("aa.*"))).toArray());
        System.out.println(c.find(o("a", o("$regex","aa.*"))).toArray());
        
        System.out.println(BSON.encode(o("a", Pattern.compile("aa.*"))).length);
        System.out.println(BSON.encode(o("a", o("$regex","aa.*"))).length);

    }

    public static DBObject o(Object... args) {
        DBObject o = new BasicDBObject();
        for (int i = 0; i < args.length; i += 2) {
            o.put((String) args[i], args[i + 1]);
        }
        return o;
    }
}