Configure MongoDB programmatically with moved credential and connection settings into .properties file

What is the best practise for Spring MongoDB configuration programmatically with moved credential and connection settings in a seprate .properties files?

I have configure it such a way but how to do it with .properties files, without any xml and probably better than my way:

App.class

@Configuration
@EnableAutoConfiguration
@ComponentScan
public class App {

    public static void main(String[] args) {
        SpringApplication.run(App.class,args);
    }
}

MongoDBConfig.class

@Configuration
public class MongoDBConfig {

        public @Bean
        MongoDbFactory mongoDbFactory() throws Exception {
            UserCredentials userCredentials = new UserCredentials("root", "qwerty");
            return new SimpleMongoDbFactory(new MongoClient(), "test", userCredentials);
        }

        public @Bean MongoTemplate mongoTemplate() throws Exception {
            return new MongoTemplate(mongoDbFactory());
        }