自定义异常处理，让网关更人性化。

版本号: Spring Cloud 2020.0.3

普遍的方式 有 完成自身的 DefaultErrorWebExceptionHandler 或 仅完成ErrorAttributes.

方式 1: ErrorWebExceptionHandler (仅作提示)

自定一个 GlobalErrorAttributes:

@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;
    }
}

完成一个

@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());
    }

    //3D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));
    }
}

方式 2, 仅完成一个 ErrorAttributes, 以遮盖默认设置的 DefaultErrorAttributes

//Spring 默认设置的就很好了.
@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);

        //务必设定, 不然会出错, 由于 DefaultErrorWebExceptionHandler 的 renderErrorResponse 方式 会获得此特性, 再次完成 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中拷贝回来的
    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);
    }
}

那样就可以了.

留意留意: 务必设定 errorAttributes.put(“status”, errorStatus.value()) , 不然会出错, 由于 DefaultErrorWebExceptionHandler 的 renderErrorResponse 方式 会获得此特性. 除非是你自己像方式 一一样再次完成 DefaultErrorWebExceptionHandler.

随后在网关ip中浏览一个不会有的服务项目, 就可以见到实际效果.

curl 'http://127.0.0.1:8900/fundmain22/abc/gogogo?id=1000' --header 'Accept: application/json'
{"exception":"org.springframework.web.server.ResponseStatusException","path":"/fundmain22/abc/gogogo","code":404,"method":"GET","requestId":"094e53e5-1","message":"404 NOT_FOUND","error":"Not Found","status":404,"timestamp":"2021-08-09T11:07:44.106 0000"} 

谢谢互联网上的各种各样文章内容…