MongoDB 2.4 - Java (insert)

import java.net.UnknownHostException;
import java.util.Arrays;

import org.bson.types.ObjectId;

import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBObject;
import com.mongodb.MongoClient;
import com.mongodb.ServerAddress;

public class MongoDB {

public static void main(String[] args) throws UnknownHostException {
MongoClient client = new MongoClient(new ServerAddress("localhost",
27017));
DB database = client.getDB("databaseName");
DBCollection collection = database.getCollection("collectionName");

collection.drop();

DBObject document01 = new BasicDBObject().append("a", 1);

System.out.println(document01);
collection.insert(document01);
System.out.println(document01);

DBObject document02 = new BasicDBObject("_id", new ObjectId()).append(
"b", 2);

System.out.println(document02);
collection.insert(document02);
System.out.println(document02);

DBObject document03 = new BasicDBObject("c", 3);
DBObject document04 = new BasicDBObject();

System.out.println(document03);
System.out.println(document04);
collection.insert(Arrays.asList(document03, document04));
System.out.println(document03);
System.out.println(document04);

client.close();
}
}