Spring Cloud Gateway 作為微服務(wù)的最前沿氮发，可以實現(xiàn)限流、鑒權(quán)等等操作冗懦，本文將以修改統(tǒng)一格式的返回參數(shù)作為講解

新建GlobalFilter的實現(xiàn)類

Spring 修改前的默認返回參數(shù)如下

{
    "status": 404,
    "error":"",
    "message": "NOT FUND",
    "path": "/test",
    "timestamp": 1565334087971
}

@Slf4j
@Component
public class OpenGatewayFilter implements GlobalFilter, Ordered {
    /** 將 List 數(shù)據(jù)以""分隔進行拼接 **/
    private static Joiner joiner = Joiner.on("");

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        ServerHttpRequest request = exchange.getRequest();
        ServerHttpResponse response = exchange.getResponse();
        DataBufferFactory bufferFactory = response.bufferFactory();

        ServerHttpResponseDecorator decorator = new ServerHttpResponseDecorator(response) {
            @Override
            public Mono<Void> writeWith(Publisher<? extends DataBuffer> body) {
               if (body instanceof Flux) {
                Flux<? extends DataBuffer> fluxBody = (Flux<? extends DataBuffer>)body;
                return super.writeWith(fluxBody.buffer().map(dataBuffers -> {
                    List<String> list = Lists.newArrayList();
                    // gateway 針對返回參數(shù)過長的情況下會分段返回爽冕，使用如下方式接受返回參數(shù)則可避免
                    dataBuffers.forEach(dataBuffer -> {
                        // probably should reuse buffers
                        byte[] content = new byte[dataBuffer.readableByteCount()];
                        dataBuffer.read(content);
                        // 釋放掉內(nèi)存
                        DataBufferUtils.release(dataBuffer);

                        list.add(new String(content, StandardCharsets.UTF_8));
                    });
                    // 將多次返回的參數(shù)拼接起來
                    String responseData = joiner.join(list);

                    // 重置返回參數(shù)
                    String result = response(responseData);
                    byte[] uppedContent =
                        new String(result.getBytes(StandardCharsets.UTF_8), StandardCharsets.UTF_8).getBytes();

                    // 修改后的返回參數(shù)應該重置長度，否則如果修改后的參數(shù)長度超出原始參數(shù)長度時會導致客戶端接收到的參數(shù)丟失一部分
                    response.getHeaders().setContentLength(uppedContent.length);

                    return bufferFactory.wrap(uppedContent);
                }));
             }
                return super.writeWith(body);
            }
        };

        return chain.filter(exchange.mutate().response(decorator).build());
    }

    @Override
    public int getOrder() {
        // 必須<=-1
        return -2;
    }

    private String response(String result) {
        try {
            JSONObject json = JSONObject.fromObject(result);
           if (json.containsKey("error")) {
                json.clear();
                json.put("code", json.get("status"));
                json.put("msg", json.getString("message"));
                json.put("payload","");
                json.put("timestamp", System.currentTimeMillis());
                result = json.toString();
            }
        } catch (Exception e) {
            log.warn("轉(zhuǎn)換JSON異常：{}", result);
        }

        return result;
    }
}

新建配置類

覆蓋默認的配置

@Configuration
@EnableConfigurationProperties({ServerProperties.class, ResourceProperties.class})
public class ErrorHandlerConfiguration {

    private final ServerProperties serverProperties;

    private final ApplicationContext applicationContext;

    private final ResourceProperties resourceProperties;

    private final List<ViewResolver> viewResolvers;

    private final ServerCodecConfigurer serverCodecConfigurer;

    public ErrorHandlerConfiguration(ServerProperties serverProperties, ResourceProperties resourceProperties,
        ObjectProvider<List<ViewResolver>> viewResolversProvider, ServerCodecConfigurer serverCodecConfigurer,
        ApplicationContext applicationContext) {
        this.serverProperties = serverProperties;
        this.applicationContext = applicationContext;
        this.resourceProperties = resourceProperties;
        this.viewResolvers = viewResolversProvider.getIfAvailable(Collections::emptyList);
        this.serverCodecConfigurer = serverCodecConfigurer;
    }

    @Bean
    @Order(Ordered.HIGHEST_PRECEDENCE)
    public ErrorWebExceptionHandler errorWebExceptionHandler(ErrorAttributes errorAttributes) {
        GatewayExceptionHandler exceptionHandler = new GatewayExceptionHandler(errorAttributes, this.resourceProperties,
            this.serverProperties.getError(), this.applicationContext);
        exceptionHandler.setViewResolvers(this.viewResolvers);
        exceptionHandler.setMessageWriters(this.serverCodecConfigurer.getWriters());
        exceptionHandler.setMessageReaders(this.serverCodecConfigurer.getReaders());
        return exceptionHandler;
    }

}

修改后的返回結(jié)果

{
    "code": 101,
    "msg": "請求方式不被支持",
    "payload": "",
    "timestamp": 1565334087971
}