Spring Cloud Gateway自定义异常处理Exception Handler的方法小结

@Component

public class GlobalErrorAttributes extends DefaultErrorAttributes{

     @Override

     public Map<String, Object> getErrorAttributes(ServerRequest request, ErrorAttributeOptions options) {

         Throwable error = super .getError(request);

         Map<String, Object> map = super .getErrorAttributes(request, options);

         map.put( "status" , HttpStatus.BAD_REQUEST.value());

         map.put( "message" , error.getMessage());

         return map;

     }

}

@Component

@Order (- 2 )

public class GlobalErrorWebExceptionHandler extends AbstractErrorWebExceptionHandler {

     public GlobalErrorWebExceptionHandler(GlobalErrorAttributes gea, ApplicationContext applicationContext,

                                           ServerCodecConfigurer serverCodecConfigurer) {

         super (gea, new WebProperties.Resources(), applicationContext);

         super .setMessageWriters(serverCodecConfigurer.getWriters());

         super .setMessageReaders(serverCodecConfigurer.getReaders());

     }

     //渲染html或json

     @Override

     protected RouterFunction<ServerResponse> getRoutingFunction( final ErrorAttributes errorAttributes) {

         return RouterFunctions.route(RequestPredicates.all(), this ::renderErrorResponse);

     }

     private Mono<ServerResponse> renderErrorResponse( final ServerRequest request) {

         final Map<String, Object> errorPropertiesMap = getErrorAttributes(request, ErrorAttributeOptions.defaults());

         return ServerResponse.status(HttpStatus.BAD_REQUEST)

                 .contentType(MediaType.APPLICATION_JSON)

                 .body(BodyInserters.fromValue(errorPropertiesMap));

     }

}

//Spring 默认的就很好了.

@Component

public class GatewayErrorAttributes extends DefaultErrorAttributes {

     private static final Logger logger = LoggerFactory.getLogger(GatewayErrorAttributes. class );

     @Override

     public Map<String, Object> getErrorAttributes(ServerRequest request,  ErrorAttributeOptions options) {

         Throwable error = super .getError(request);

         Map<String, Object> errorAttributes = new HashMap<>( 8 );

         errorAttributes.put( "message" , error.getMessage());

         errorAttributes.put( "method" , request.methodName());

         errorAttributes.put( "path" , request.path());

         MergedAnnotation<ResponseStatus> responseStatusAnnotation = MergedAnnotations

                 .from(error.getClass(), MergedAnnotations.SearchStrategy.TYPE_HIERARCHY).get(ResponseStatus. class );

         HttpStatus errorStatus = determineHttpStatus(error, responseStatusAnnotation);

         //必须设置, 否则会报错, 因为 DefaultErrorWebExceptionHandler 的 renderErrorResponse 方法会获取此属性, 重新实现 DefaultErrorWebExceptionHandler也可.

         errorAttributes.put( "status" , errorStatus.value());

         errorAttributes.put( "code" , errorStatus.value());

         //html view用

         errorAttributes.put( "timestamp" , new Date());

         //html view 用

         errorAttributes.put( "requestId" , request.exchange().getRequest().getId());

         errorAttributes.put( "error" , errorStatus.getReasonPhrase());

         errorAttributes.put( "exception" , error.getClass().getName());

         return errorAttributes;

     }

     //从DefaultErrorWebExceptionHandler中复制过来的

     private HttpStatus determineHttpStatus(Throwable error, MergedAnnotation<ResponseStatus> responseStatusAnnotation) {

         if (error instanceof ResponseStatusException) {

             return ((ResponseStatusException) error).getStatus();

         }

         return responseStatusAnnotation.getValue( "code" , HttpStatus. class ).orElse(HttpStatus.INTERNAL_SERVER_ERROR);

     }

}