import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.client.HttpStatusCodeException;
+import org.springframework.web.client.RestClientResponseException;
import org.springframework.web.context.request.WebRequest;
import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
/**
- * Catches Http status code exceptions and builds a response with code 502 and
- * some details wrapped in an ErrorTransport object. This factors out try-catch
+ * Catches certain exceptions. This controller advice factors out try-catch
* blocks in many controller methods.
*
- * Why 502? I quote: <blockquote>HTTP server received an invalid response from a
- * server it consulted when acting as a proxy or gateway.</blockquote>
- *
* Also see:<br>
* https://www.baeldung.com/exception-handling-for-rest-with-spring
* https://www.springboottutorial.com/spring-boot-exception-handling-for-rest-services
// Superclass has "logger" that is exposed here, so use a different name
private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
- /*
- * Generates the response when a REST controller method takes an
- * HttpStatusCodeException.
+ /**
+ * Logs the error and generates a JSON response when a REST controller method
+ * takes a RestClientResponseException. This is thrown by the Http client when a
+ * remote method returns a non-2xx code. All the controller methods are proxies
+ * in that they just forward the request along to a remote system, so if that
+ * remote system fails, return 502 plus some details about the failure, rather
+ * than the generic 500 that Spring-Boot will return on an uncaught exception.
+ *
+ * Why 502? I quote: <blockquote>HTTP server received an invalid response from a
+ * server it consulted when acting as a proxy or gateway.</blockquote>
*
- * @param ex The exception
+ * @param ex
+ * The exception
*
- * @param request The original request
+ * @param request
+ * The original request
*
* @return A response entity with status code 502 plus some details in the body.
*/
- @ExceptionHandler(HttpStatusCodeException.class)
- public final ResponseEntity<ErrorTransport> handleHttpStatusCodeException(HttpStatusCodeException ex,
- WebRequest request) {
- log.warn("handleHttpStatusCodeException: request {}, status code {}", request.getDescription(false),
- ex.getStatusCode());
- return new ResponseEntity<>(new ErrorTransport(ex.getRawStatusCode(), ex.getResponseBodyAsString(), ex),
- HttpStatus.BAD_GATEWAY);
+ @ExceptionHandler({ RestClientResponseException.class })
+ public final ResponseEntity<ErrorTransport> handleProxyMethodException(Exception ex, WebRequest request) {
+ // Capture the full stack trace in the log.
+ log.error("handleProxyMethodException: request {}, exception {}", request.getDescription(false), ex);
+ if (ex instanceof HttpStatusCodeException) {
+ HttpStatusCodeException hsce = (HttpStatusCodeException) ex;
+ return new ResponseEntity<>(new ErrorTransport(hsce.getRawStatusCode(), hsce.getResponseBodyAsString(),
+ ex.toString(), request.getDescription(false)), HttpStatus.BAD_GATEWAY);
+ } else {
+ return new ResponseEntity<>(new ErrorTransport(500, ex), HttpStatus.BAD_GATEWAY);
+ }
}
}