MongoDB 2.4 - Java (findAndModify)

import java.net.UnknownHostException;

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

public class MongoDB {

private static MongoClient client;
private static DBCollection collection;

public static void main(String[] args) throws UnknownHostException {
createCollection();

int first;
int numNeeded;

numNeeded = 2;
first = getRange(numNeeded);

printCollection();
System.out.println("Range: " + first + "-" + (first + numNeeded - 1));

numNeeded = 3;
first = getRange(numNeeded);

printCollection();
System.out.println("Range: " + first + "-" + (first + numNeeded - 1));

numNeeded = 10;
first = getRange(numNeeded);

printCollection();
System.out.println("Range: " + first + "-" + (first + numNeeded - 1));

client.close();
}

private static int getRange(int range) {
DBObject document = collection.findAndModify(new BasicDBObject("_id",
"abc"), null, null, false, new BasicDBObject("$inc",
new BasicDBObject("counter", range)), true, true);

return (Integer) document.get("counter") - range + 1;
}

private static void createCollection() throws UnknownHostException {
client = new MongoClient(new ServerAddress("localhost", 27017));

DB database = client.getDB("databaseName");

collection = database.getCollection("collectionName");

collection.drop();
}

private static void printCollection() {
DBCursor result = null;

try {
result = collection.find();

while (result.hasNext()) {
DBObject document = result.next();

System.out.println(document);
}
} finally {
result.close();
}
}
}