如何将 Java POJO / Json 发布到 Play Framework v2.2.1 Controller Z9D5D5D543DE68F05BBB5 方法

Question

I am writing an API using Java play framework. I would like to post a Json via a rest client like Postman, while testing the Play controller.

Version of Java Play = 2.2.1

Controller method:

public static Result submitDetails(DetailsVO detailsVO) throws Exception

Routes config

POST    /submit                     controllers.application.ProcessDetails.submitDetails(detailsVO:DetailsVO)

Below is my POJO

import java.io.Serializable;
import java.util.List;

public class DetailsVO implements Serializable {
    public DetailsVO(){}

    private String firstName;
    private String middleName;

    private List<Details> detailsList;

//Setter and getter for first name and last name

public List<Details> getDetailsList() {
        return detailsList;
    }

    public void setDetailsList(List<Details> detailsList) {
        this.detailsList = detailsList;
    }

}

After adding the routes entry, I am getting this error "Cannot resolve reference"

Please, could some advice on how to define a post method that takes a Java POJO in the routes?

Answer 1

I dont think it is possible to use your VO directly in play for java. You need to use the play request type. And then from the request you get the body as JSON. You can use any JSON parser for this. Play has one, but you can use whatever you like. Your route would look like this:

POST    /submit                     @controllers.HomeController.submitDetails(request: Request)

Remove the static from your controller function, and let it take the Http.Request instead of the VO.

public Result submitDetails(Http.Request request) throws Exception {
    ObjectMapper objectMapper = new ObjectMapper();
    JsonNode json = request.body().asJson();
    DetailsVO dvo = objectMapper.convertValue(json, DetailsVO.class);
    return ok(json.toString());
}

For this example i used the Jackson JSON parser. For this particular solution to work you also need your fields to be public, because the parser does not work for the private fields. I would suggest using the play documentation on their website. It can be found here: https://www.playframework.com/documentation/2.8.x/JavaHome I would suggest trying scala when you're trying out the play framework, it makes for much cleaner code with this framework.