spring data mongodb configuration in spring boot based project

Question

I am writing code with spring boot which will take csv as input and create mongodb collection and insert it to mongodb.

Currently I am sticking in using mongodb in spring boot based code. I am getting NullPointerException while using save method on MongoRepository interface.

Probably this problem is due to incorrect configuration in application.yml file Below is mongodb specific changes in application.yml in src/main/resources directory.

spring:
   data:
      mongodb.host: localhost
      mongodb.port: 27017
      mongodb.uri: mongodb://localhost/test
      mongo.repositories.enabled: true

Application.java file is below:

@Configuration
@EnableMongoRepositories
@Import(RepositoryRestMvcConfiguration.class)
@EnableAutoConfiguration  // Sprint Boot Auto Configuration
@ComponentScan(basePackages = "com.khoubyari.example")
public class Application extends SpringBootServletInitializer {

private static final Class<Application> applicationClass = Application.class;
private static final Logger log = LoggerFactory.getLogger(applicationClass);

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


@Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
    return application.sources(applicationClass);
}
}

If Application.java implements CommandLineRunner and write mongodb insertion specific code in overrided method run, code is working fine. This code is available in this URL: https://spring.io/guides/gs/accessing-data-mongodb/

but, my Application.java extends SpringBootServletInitializer class and override configure(SpringApplicationBuilder application) method. Please look at above for my Application.java.

I need to use same db specific code (as in same code for which URL I mentioned above in Application.java class) in utility class existing in different package for my spring boot based project.

Custom repository interface is below:

CustomRepository.java:

public interface CustomRepository extends MongoRepository<CsvPojo, String>{

}

In utility class, I just want to inject CustomRepository and use save method to save created CsvPojo in mongodb. But I am geiing NullPointerException while executing line customRepository.save(csvPojo);

Please suggest! If other information is needed, please tell me!

Regards, Shobhit

Solution

Calling save method in spring rest controller resolved the issue in stead of calling from utility class.

I just inject CustomRepository interface in controller and using save method!

I got the solution after studying "About the Service" section from https://github.com/khoubyari/spring-boot-rest-example

I need to explore more in spring boot but anyways problem is resolved after above posted efforts!