How to implement the simplest alien in a REST webservice?

Question

I need a JSON endpoint that return data directally from a stored procedure. Example:

@Procedure(\"complex\"         


        

Answer 1

Im not really sure if I understand your question well but this is my solution.

I created a simple procedure on a oracle DB:

PROCEDURE TESTPROCOUTPUT
   (param2 OUT VARCHAR2)
   IS
   GETPARAM VARCHAR2(100);
BEGIN
    param2 := 'procedure Called';
END TESTPROCOUTPUT;

To use @Procedure in the Spring environment you will need an Entity and a Repository. So I created a simple Entity and it's Repository:

@Entity
public class City {

    @Id
    private String cityCode;

    //...getter/setter
}

Repository:

public interface LandRepository extends CrudRepository {

    @Procedure(name="TESTPROCOUTPUT", outputParameterName="param2")
    String TESTPROCOUTPUT();
}

It is important that the method name has the same name like the procedure has. (Not sure if its just for oracle the case. And could also be in camelCase I think)

So in your controller you can now easily autowire the repository (or if you have an implementation of the interface use this).

@Controller
public class CityController {

    private CityRepository cityRepository;

    @RequestMapping(value="/howto", method=RequestMethod.GET)
    @ResponseStatus(HttpStatus.OK)
    @ResponseBody
    public String howto() { 
        String s = cityRepository.TESTPROCOUTPUT();
        return "{\"result\":" + s + "}";
    }

    public CityRepository getCityRepository () {
        return cityRepository;
    }

    @Autowired
    public void setCityRepository (CityRepository cityRepository) {
        this.cityRepository= cityRepository;
    }
}

And the result is:

So you are not able to use @Procedure annotation on non repository methods.

Annotation to declare JPA 2.1 stored procedure mappings directly on repository methods.