Singleton MongoClient for Java Application

MongoServices.java

import com.mongodb.*;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import org.bson.Document;
import tests.TestBaseSetup;
import java.util.Arrays;
import java.util.Properties;
/**
 * Created by Amol Chavan on 03-06-2016.
 */
public enum DBOps {
    INSTANCE;
    private MongoClient mongoClient;
    Properties DBConfig ;

    String serverIP, dbName, dbUsername, dbPassword;
    int port;

    private DBOps() {
            if (mongoClient == null) {
                mongoClient = getClient();
            }
    }

    private MongoClient getClient() {
        DBConfig = TestBaseSetup.Config;
        serverIP = DBConfig.getProperty("ServerIPAddress");
        port = Integer.parseInt(DBConfig.getProperty("DBPort"));
        dbName = DBConfig.getProperty("DBName");
        dbUsername = DBConfig.getProperty("UserName");
        dbPassword = DBConfig.getProperty("DBPassword");
        MongoCredential credential = MongoCredential.createCredential(dbUsername, dbName, dbPassword.toCharArray());
        return new MongoClient(new ServerAddress(serverIP,port), Arrays.asList(credential));
    }

    public int getCountInCollection(String collectionName, String key, String value) {
        try {
            MongoDatabase mongoDatabase = mongoClient.getDatabase(dbName);
            Document query = new Document();
            query.put(key, value);
            MongoCollection<Document> collection = mongoDatabase.getCollection(collectionName);
            return ((int) collection.count(query));
        } catch (MongoException e) {
            System.out.println("Test");
            return 0;
        }
    }

    public boolean removeFromCollection(String collectionName, String key, String value) {
        try {
            MongoDatabase mongoDatabase = mongoClient.getDatabase(dbName);
            Document  query= new Document();
            query.put(key, value);
            MongoCollection<Document> collection = mongoDatabase.getCollection(collectionName);
            int count = (int)collection.count(query);
            if (count>0 && count <2){
                collection.deleteOne(query);
                return true;
            }
            return false;
        } catch (MongoException e) {
            return false;
        }
    }
}