CODEWITHSUNDEEP
javaspringjackson
RSX
RSX

Reputation: 2479

Spring4 MVC serialize enum as string with quotes

i have a rest controller in a spring boot mvc container

@RestController
public class LoginController {

    @RequestMapping("rest/login")
    public Response login() {
        return Response.GRANTED;
    }

    public static enum Response {

        GRANTED, DENIED;

    }
}

I have to use double quotes for checking the return type after request a rest resource. how to avoid the double quotes?

$http.post("rest/login", $scope.data).success(function(data) {
  if (data === "\"GRANTED\"") {
   alert("GRANTED")
  } else if (data === "DENIED") {
   alert("DENIED")
  };

@RestController public class LoginController {

@RequestMapping("rest/login")
public String login() {
    return Response.GRANTED.name();
}

public static enum Response {

    GRANTED, DENIED;

}

}

bring the result I want but I want the type safe return type Response and not String.

Thanks for help.

Upvotes: 1

Views: 1983

Answers (1)

Sotirios Delimanolis
Sotirios Delimanolis

Reputation: 279990

A @RestController is like a @Controller annotated with @ResponseBody. That is, each handler is implicitly annotated with @ResponseBody. With any reference type other than String (and a few others), the default target content-type is JSON.

The 6 data types in JSON are Object, Array, Number, String, true, false, and null. How would you map an enum constant? The default that Jackson (which backs the default JSON HttpMessageConverter) serializes an enum constant to a JSON String. That's arguably the best matching JSON data type.

You could force it to write the value without quotes by providing your own JsonSerializer

@JsonSerialize(using = ResponseSerializer.class)
public static enum Response {
...
class ResponseSerializer extends JsonSerializer<Response> {
    @Override
    public void serialize(Response value, JsonGenerator jgen,
            SerializerProvider provider) throws IOException,
            JsonProcessingException {
        jgen.writeRaw(value.name());
    }
}

but I don't recommend it since you wouldn't be producing valid JSON.

You should really consider what others have suggested and use the various HTTP status codes.

Upvotes: 1

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