Question

我正在使用Spring Boot版本-2.0.6.RELEASE和Spring Cloud版本-Finchley.SR2

并且我创建了自定义网关过滤器来修改请求正文。

但是在使用Flux将请求主体转换为字符串时，我得到了一个空字符串。我需要一种方法来获取与我的请求正文相对应的字符串。

@Override
public Mono filter(ServerWebExchange exchange, GatewayFilterChain chain) {
    ServerHttpRequest request = (ServerHttpRequest) exchange.getRequest();
    String s = resolveBodyFromRequest(request);
     /* s comes out to be "" */
    return chain.filter(newExchange);


}



private String resolveBodyFromRequest(ServerHttpRequest serverHttpRequest){
    //Get the request body
    Flux<DataBuffer> body = serverHttpRequest.getBody();
    StringBuilder sb = new StringBuilder();

    body.subscribe(buffer -> {
        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();

}

Answer 1

您可以使用ModifyRequestBodyGatewayFilterFactory，我相信它是Finchley一部分的Spring Cloud Gateway 2.0.2中包含的。

例如：

@Override
public GatewayFilter apply(Config config) {
   return (exchange, chain) -> {
        ModifyRequestBodyGatewayFilterFactory.Config modifyRequestConfig = new ModifyRequestBodyGatewayFilterFactory.Config()
                .setContentType(ContentType.APPLICATION_JSON.getMimeType())
                .setRewriteFunction(String.class, String.class, (exchange1, originalRequestBody) -> {
                    String modifiedRequestBody = yourMethodToModifyRequestBody(originalRequestBody);
                    return Mono.just(modifiedRequestBody);
                });

        return new ModifyRequestBodyGatewayFilterFactory().apply(modifyRequestConfig).filter(exchange, chain);
    };
}

Answer 2

这是Spring Cloud Gateway 2.2.5中的另一种方法，我们将使用ReadBodyPredicateFactory，因为这会将具有属性键cachedRequestBodyObject的requestBody缓存到ServerWebExchange

创建始终为真的谓词

@Component
public class TestRequestBody implements Predicate
{
    @Override
    public boolean test(Object o)
    {
        return true;
    }
}

在application.yml中，添加谓词

spring:
  cloud:
    gateway:
      routes:
       ....
          predicates:
            .....
            - name: ReadBodyPredicateFactory
              args:
                inClass: "#{T(String)}" 
                predicate: "#{@testRequestBody}"

在您自己的过滤器中，如下所示获取requestBody：

    @Override
    public GatewayFilter apply(Object config)
    {
        return (exchange, chain) -> {

            String requestBody = exchange.getAttribute("cachedRequestBodyObject");

        };
    }

Answer 3

一旦您读取（通过读取日志）请求主体，请求本身就会下降。 Spring Cloud网关需要记录请求正文的内容，但请求正文只能读取一次。如果在读取请求主体后未对其进行封装，则后者服务将无法读取主体数据。 follow this

Answer 4

使用spring cloud网关重写主体请求对@ tony.hokan答案https://stackoverflow.com/a/64080867/1484823进行精炼，以将请求主体（以及可能的响应主体）保存为org.springframework.web.server.ServerWebExchange的属性

    @Bean
    public RouteLocator myRouteSavingRequestBody(RouteLocatorBuilder builder) {
        return builder.routes()
            .route("my-route-id",
                p -> p
                    .path("/v2/**") //your own path filter
                    .filters(f -> f
                        .modifyResponseBody(String.class, String.class,
                            (webExchange, originalBody) -> {
                                if (originalBody != null) {
                                    webExchange.getAttributes().put("cachedResponseBodyObject", originalBody);
                                    return Mono.just(originalBody);
                                } else {
                                    return Mono.empty();
                                }
                            })
                        .modifyRequestBody(String.class, String.class,
                            (webExchange, originalBody) -> {
                                if (originalBody != null) {
                                    webExchange.getAttributes().put("cachedRequestBodyObject", originalBody);
                                    return Mono.just(originalBody);
                                } else {
                                    return Mono.empty();
                                }
                            })

                    )
                    .uri("https://myuri.org")
            )
            .build();
    }

在您自己的过滤器中，如下所示获取requestBody：

    @Override
    public GatewayFilter apply(Object config)
    {
        return (exchange, chain) -> {

            String requestBody = exchange.getAttribute("cachedRequestBodyObject");

        };
    }

从ServerHttpRequest / Flux <DataBuffer>获取请求主体字符串

4 个答案: