Spring Boot configuration with Morphia?

Question

I do not want to utilize the Spring DATA MongoDB support. I want to leverage the ORM for MongoDB called Morphia.

https://github.com/mongodb/morphia

I want to configure the Morphia with Spring Boot. I want to externalize the configuration of Morphia in a way that it follows the Spring Boot philosophy.

I want to leverage the environment variables for the configuration of Morphia properties.

What would be the Spring Boot approach to achieve this ?

In a simple main program on would do following to get the Morhpia ORM working.

private Morphia morphia; 
private MongoClient mongoClient; 

morphia = new Morphia();
// Person is an entity object with Morphia annotations
morphia.map(Person.class);

// THESE properties MUST be read from environment variables in Spring BOOT.
final String host = "localhost";
final int port = 27017;

mongoClient = new MongoClient(host, port);

//Set database
// this instance would be autowired all data access classes
Datastore ds  = morphia.createDatastore(mongoClient, "dataStoreInstanceId");

// this is how instance would be used in those data accesses classes
Person p = ds.find(Person.class, "username", "john").get();

Answer 1

The Spring Boot like approach would be to create a AutoConfiguration with the needed properties which creates an instance of Datastore as bean.

In the Reference Guide you will find how to set properties and connect to a MongoDB.

An AutoConfiguration for Morphia could look like this:

@Configuration
public class MorphiaAutoConfiguration {

    @Autowired
    private MongoClient mongoClient; // created from MongoAutoConfiguration

    @Bean
    public Datastore datastore() {
        Morphia morphia = new Morphia();

        // map entities, there is maybe a better way to find and map all entities
        ClassPathScanningCandidateComponentProvider entityScanner = new ClassPathScanningCandidateComponentProvider(true);
        entityScanner.addIncludeFilter(new AnnotationTypeFilter(Entity.class));
        for (BeanDefinition candidate : scanner.findCandidateComponents("your.basepackage")) { // from properties?
            morphia.map(Class.forName(candidate.getBeanClassName()));
        }

        return morphia.createDatastore(mongoClient, "dataStoreInstanceId"); // "dataStoreInstanceId" may come from properties?
    }
}

You could then autowire your Datastore in other Spring beans the usual way:

    @Autowired
    private Datastore datastore;

If some points are not correct or unclear just take a look at the existing *AutoConfiguration classes in Spring Boot.