springcloud gateway 获取post请求体Json分段导致不全的解决方案

r囧r小猫 2023-07-18 09:43 18阅读 0赞

开发版本  
springboot 2.0.8.RELEASE + springcloud Finchley.SR2 + spring cloud gateway

前端客户端采用post发送请求，content\_type： application/json,  
spring cloud gateway需要从request的中取出body进行网关的鉴权处理，然后把处理之后的数据重新封装到body中转发给下游业务系统，  
最之前的方式采用的是以下方式读取请求体：  
 AtomicReference<String> bodyRef = new AtomicReference<>();//缓存读取的request body信息  
               Flux<DataBuffer> fluxBody = exchange.getRequest().getBody();  
               fluxBody.subscribe(buffer -> \{  
                     CharBuffer charBuffer = StandardCharsets.UTF\_8.decode(buffer.asByteBuffer());  
                     DataBufferUtils.release(buffer);  
                     bodyRef.set(charBuffer.toString());  
               \});  
               String bodyStr = bodyRef.get();

偶尔前端提出验签失败，检查上送请求体报文时发现错误：网关获取的body不完整。

尝试了网上的写法来获取body，于是改成了以下的写法来亲自验证，偶尔还是发现网关获取的body体不完整，说明此方法还是不行，有坑。

private String resolveBodyFromRequest(ServerHttpRequest serverHttpRequest)\{  
        //获取请求体  
        Flux<DataBuffer> body = serverHttpRequest.getBody();  
        StringBuilder sb = new StringBuilder();  
        body.subscribe(buffer -> \{  
            List<String> list = Lists.newArrayList();  
            byte\[\] bytes = new byte\[buffer.readableByteCount()\];  
            buffer.read(bytes);  
            DataBufferUtils.release(buffer);  
            String bodyString = new String(bytes, StandardCharsets.UTF\_8);  
            sb.append(bodyString);  
        \});  
        return sb.toString();  
    \}

继续查询相关资料，有几篇文件介绍了要解决获取body不完整的情况得代用code路由的方式来配置，而不能采用yml，于是继续尝试。  
    @Bean  
    public RouteLocator tpauditRoutes(RouteLocatorBuilder builder) \{  
        return builder.routes()  
                .route(r ->r  
                        .readBody(String.class, requestBody -> \{  
                            //log.info("requestBody is \{\}", requestBody);  
                            // 这里 r.readBody做了一个前置语言，这样就可以在filter中通过exchange.getAttribute("cachedRequestBodyObject"); 获取body体  
                            return true;  
                        \}).and()  
                        .path("/gw/xxxdmin/\*\*")  
                        .filters(f -> f.stripPrefix(1)  
                                       .hystrix(h -> h.setName("Hystrix").setFallbackUri("forward:/timeoutfallback")))  
                        .uri("lb://ADMIN/")  
                )  
                .route(r ->r  
                        .readBody(String.class, requestBody -> \{  
                            //log.info("requestBody is \{\}", requestBody);  
                            // 这里 r.readBody做了一个前置语言，这样就可以在filter中通过exchange.getAttribute("cachedRequestBodyObject"); 获取body体  
                            return true;  
                        \}).and()  
                        .path("/gw/xxxapp/\*\*")  
                        .filters(f -> f.stripPrefix(1)  
                                       .hystrix(h -> h.setName("Hystrix").setFallbackUri("forward:/timeoutfallback")))  
                        .uri("lb://APP/")  
                )

.build();  
    \}

然后移除yml中配置的路由：  
      routes:  
            
        - id:  xxxAPP  
          uri: lb://xxxAPP  
          predicates:  
          - Path=$\{server.servlet.context-path\}/xxxapp/\*\*  
          filters:  
          - StripPrefix=1  
          - name: RequestRateLimiter  
            args:  
              redis-rate-limiter.replenishRate: 1 \#允许用户每秒处理多少个请求  
              redis-rate-limiter.burstCapacity: 1 \#令牌桶的容量,允许在一秒钟内完成的最大请求数  
              key-resolver: "\#\{@addressKeyResolver\}" \#使用SpEL按名称引用bean  
              \# 降级配置  
          - name: Hystrix  
            args:  
              name: default  
              fallbackUri: forward:/timeoutfallback

业务处理过滤器中通过String bodyStr = exchange.getAttribute("cachedRequestBodyObject");方法获取请求体，  
最终问题得以解决。

但本人喜欢采用yml配置文件的形式来做路由，所以对于yml路由的配置，此坑还需要进一步的排查解决。