Example of how one can issue a `splitVector` command in MongoDB 2.4.0 using the Java client when `--auth` is enabled and the requesting user exists in the `admin` db.

Main.java

import java.net.UnknownHostException;

import com.mongodb.BasicDBObject;
import com.mongodb.BasicDBObjectBuilder;
import com.mongodb.CommandResult;
import com.mongodb.DB;
import com.mongodb.DBObject;
import com.mongodb.Mongo;
import com.mongodb.MongoClient;
import com.mongodb.MongoClientURI;

public class Main {

  public static void main(String... args) throws UnknownHostException {
    // URI with db and collection
    String uri = args[0];

    MongoClientURI mongoClientUri = new MongoClientURI(uri);
    Mongo mongo = new MongoClient(mongoClientUri);

    // Authenicate: This is required to happen against the *same* mongo object
    DB admin = mongo.getDB("admin");
    admin.authenticate(mongoClientUri.getUsername(), mongoClientUri.getPassword());

    DB db = mongo.getDB(mongoClientUri.getDatabase());
    String collectionName = db.getCollection(mongoClientUri.getCollection()).getFullName();

    DBObject command = BasicDBObjectBuilder //
        .start("splitVector", collectionName) //
        .add("keyPattern", new BasicDBObject("_id", 1)) //
        .add("maxChunkSize", 8) //
        .get();

    System.out.println("Sending: " + command);
    CommandResult result = db.command(command);
    System.out.println("Received: " + result);
  }
}