Rest template result is getting null in api call in spring boot

Question

I am using below code to call remote API to remove user id( http://localhost:8080/remove ).

try {
final RestTemplate restTemplate = new RestTemplate();
    final UriComponentsBuilder builder = 
UriComponentsBuilder.fromUriString(url);
    builder.queryParam("acdc_id", acdcId);
ResponseEntity<ServiceResponse> result =
            restTemplate.exchange(
                builder.toUriString(),
                HttpMethod.DELETE,
                null,
                ServiceResponse.class);
}catch(Exception e){
//exception handling
}

Remote API return 200 http code for success flow(working fine), but when some user id will not available then API sent below custom response:

{
"error code": "404",
"error": "USER ID Node not found : xyz"
} 

I have already ServiceResponse.java class to get above response, but Rest Template returning below error in this case.

org.springframework.web.client.HttpClientErrorException$NotFound: 404 null
at org.springframework.web.client.HttpClientErrorException.create(HttpClientErrorException.java:85)
at org.springframework.web.client.DefaultResponseErrorHandler.handleError(DefaultResponseErrorHandler.java:122)
at org.springframework.web.client.DefaultResponseErrorHandler.handleError(DefaultResponseErrorHandler.java:102)
at org.springframework.web.client.ResponseErrorHandler.handleError(ResponseErrorHandler.java:63)
at org.springframework.web.client.RestTemplate.handleResponse(RestTemplate.java:778)
at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:736)
at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:670)
at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:579) 

My ServiceResponse class is,

@JsonIgnoreProperties(ignoreUnknown = true)
public class ServiceResponse {

@JsonProperty(value = "error code")
private String errorCode;

@JsonProperty(value = "error")
private String error;

/**
 * @return the error.
 */
public String getError() {
    return error;
}

/**
 * @param error The error to set.
 */
public void setError(final String error) {
    this.error = error;
}

/**
 * @return the errorCode.
 */
public String getErrorCode() {
    return errorCode;
}

/**
 * @param errorCode The errorCode to set.
 */
public void setErrorCode(final String errorCode) {
    this.errorCode = errorCode;
}

}

Could you please help me here to fix my issue, or provide any suggestion, how I can get proper response from API instead null error

Answer 1

As I mentioned in the comment , you're getting HttpClientErrorException, which should be caught and dealt with. You're catching the whole Exception class, but there is no code in it. Or you can use @ControllerAdvice and @ExceptionHandler together to achieve this as well.

Answer 2

You can use Controller Advice @ControllerAdvice annotation to handle the exceptions . You can send Custom response from the method. You can define exceptionHandler for HttpClientErrorException and send custom response from this method.

Please check https://www.tutorialspoint.com/spring_boot/spring_boot_exception_handling.htm for further details.

One more option is you can use CustomResponseErrorHandler something like below

@Component
public class RestTemplateResponseErrorHandler 
  implements ResponseErrorHandler {

    @Override
    public boolean hasError(ClientHttpResponse httpResponse) 
      throws IOException {

        return (
          httpResponse.getStatusCode().series() == CLIENT_ERROR 
          || httpResponse.getStatusCode().series() == SERVER_ERROR);
    }

    @Override
    public void handleError(ClientHttpResponse httpResponse) 
      throws IOException {

        if (httpResponse.getStatusCode()
          .series() == HttpStatus.Series.SERVER_ERROR) {
            // handle SERVER_ERROR
        } else if (httpResponse.getStatusCode()
          .series() == HttpStatus.Series.CLIENT_ERROR) {
            // handle CLIENT_ERROR
            if (httpResponse.getStatusCode() == HttpStatus.NOT_FOUND) {
                throw new NotFoundException();
            }
        }
    }
}

And then use it like

@Bean
    RestTemplate restTemplate() {
        RestTemplate restTemplate = new RestTemplate();
        restTemplate.setErrorHandler(new RestTemplateResponseErrorHandler());

        return restTemplate;
    }

Please check https://www.baeldung.com/spring-rest-template-error-handling for ResponseErrorHandler