Spring FeignClient - Treat RESTful xml response as JSON

Question

I'm using Spring FeignClient to access a RESTful endpoint, the endpoint returns an xml, I want to get the response as a JSON, which in turn will map to a POJO.

1) When I access the endpoint on the browser, I get response as below, 
<ns3:Products xmlns:ns2="http://schemas.com/rest/core/v1" xmlns:ns3="http://schemas/prod/v1">
<ProductDetails>
<ProdId>1234</ProdId>
<ProdName>Some Text</ProdName>
</ProductDetails>
</ns3:Products>


2) @FeignClient(value = "productApi", url = "http://prodservice/resources/prod/v1")
public interface ProductApi {

   @GetMapping(value="/products/{productId}", produces = "application/json")
   ProductDetails getProductDetails(@PathVariable("productId") String productId) 

    // where, /products/{productId} refers the RESTful endpoint 
    // by mentioning, produces = "application/json", I believe the response xml would be converted to JSON Java POJO. 


3) POJO
public class ProductDetails {
private String ProdId;
private String ProdName;

//...setters & getters 
} 

4) Service Layer 
ProductDetails details = productApi.getProductDetails(productId); 

In the 'details' object, both ProdId & ProdName are coming as null. Am I missing anything here? Firstly, Is it possible to get response as JSON instead of XML?

Answer 1

If that RESTful service is programmed to return only xml-response, then you cannot ask it to give you json-based response.

But in your case the problem is with class where you want to map the result. This xml response actually wraps ProductDetails tag into ns3:Products .

So you need to create another class which will hold a reference to ProductDetails object:

public class Product {   //class name can be anything 
    private ProductDetails ProductDetails;
    //getters, setters
}

Then change the type of getProductDetails method to Product .

If you still get nulls in your response, then it's probably because of ObjectMapper configuration. But you can always add @JsonProperty annotation for your fields (in this case it would be @JsonProperty("ProductDetails") for ProductDetails field in Product , and @JsonProperty("ProdId") and @JsonProperty("ProdName") for fields in ProductDetails ).