How to convert Mono<String> to Mono<MyObject>?

Question

I am writing a simple get method to retrieve reviews from an API URL. The API is returning json data as String. Returning Mono<Object> throws an error. Please find below the HTTP response.

{
    "timestamp": "2019-02-05T11:25:33.510+0000",
    "path": "Some URL",
    "status": 500,
    "error": "Internal Server Error",
    "message": "Content type 'text/plain;charset=utf-8' not supported for bodyType=java.lang.Object"
}

I found that the response is a string. So returning Mono<String> is working fine. But I want to return Mono<MyObject> from the API response.

How do I convert Mono<String> to Mono<MyObject>? I could not find any solutions on google except How to get String from Mono<String> in reactive java.

Below is my service class:

@Service
public class DealerRaterService {
    WebClient client = WebClient.create();
    String reviewBaseUrl = "Some URL";

    public Mono<Object> getReviews(String pageId, String accessToken) {
        String reviewUrl = reviewBaseUrl + pageId + "?accessToken=" + accessToken;
        return client.get().uri(reviewUrl).retrieve().bodyToMono(Object.class);
    }
}

Edit: Adding my controller class:

@RestController
@RequestMapping("/path1")
public class DealerRaterController {

    @Autowired
    DealerRaterService service;

    @RequestMapping("/path2")
    public Mono<Object> fetchReview(@RequestParam("pageid") String pageId,
            @RequestParam("accesstoken") String accessToken) throws ParseException {
        return service.getReviews(pageId, accessToken);
    }
}

Let me know you need any more information.

Answer 1

This is how I fixed my problem. Used map to retrieve string and converting that string to my POJO class using ObjectMapper class.

@Service
public class DealerRaterService {
    WebClient client = WebClient.create();
    String reviewBaseUrl = "some url";

    public Mono<DealerReview> getReviews(String pageId, String accessToken)
            throws JsonParseException, JsonMappingException, IOException {
        String reviewUrl = reviewBaseUrl + pageId + "?accessToken=" + accessToken;
        Mono<String> MonoOfDR = client.get().uri(reviewUrl).retrieve().bodyToMono(String.class);

        return MonoOfDR.map(dealerRater -> {
            try {
                DealerReview object = new ObjectMapper().readValue(dealerRater, DealerReview.class);
                return object;
            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;
        });

    }

}