Myujth

We are using Zuul, Eureka and spring boot application services for REST APIs.

Suppose my spring boot service is down and when I tried to access the API using Zuul API gateway, I am getting ZuulException and response is below :

 "timestamp": "2018-10-12T14:29:09.632+0000",
 "status": 500,
 "error": "Internal Server Error",
 "exception": "com.netflix.zuul.exception.ZuulException",
 "message": "GENERAL"

I want to customize the response format like below:

 "success": false,
 "message": "Service is down. Please try later"

I tried to implement https://stackoverflow.com/a/39841785/5506061 but its not working for me.

Please suggest how to customize the response for ZuulException.

You can implement your own FallbackProvider and customize the response based on the cause if needed.

Something like :

@Component
public class CustomFallbackBasedOnCause implements FallbackProvider 

private static final String DEFAULT_MSG = ""success": false,"message": "Service is down. Please try later"";

@Override
public String getRoute() 
 return "*"; // * = all routes


@Override
public ClientHttpResponse fallbackResponse(final Throwable cause) 
 if (cause instanceof HystrixTimeoutException) 
 return response(HttpStatus.GATEWAY_TIMEOUT);
 else 
 return fallbackResponse();
 


@Override
public ClientHttpResponse fallbackResponse() 
 return response(HttpStatus.INTERNAL_SERVER_ERROR);


private ClientHttpResponse response(final HttpStatus status) 
 return new ClientHttpResponse() 
 @Override
 public HttpStatus getStatusCode() throws IOException 
 return status;
 

 @Override
 public int getRawStatusCode() throws IOException 
 return status.value();
 

 @Override
 public String getStatusText() throws IOException 
 return status.getReasonPhrase();
 

 @Override
 public void close() 
 

 @Override
 public InputStream getBody() throws IOException 
 return new ByteArrayInputStream(DEFAULT_MSG.getBytes());
 

 @Override
 public HttpHeaders getHeaders() 
 HttpHeaders headers = new HttpHeaders();
 headers.setContentType(MediaType.APPLICATION_JSON);
 return headers;
 
 ;

As you can see in the getRoute() method, you can specify if this customFallback will be used for all routes (return "*") or for a specific route.

In case you work with Registry service (e.g Eureka). You don’t specify the route URL but the service id instead. return "SERVICEID"