java - 从 ServerHttpRequest/Flux 获取请求体字符串

Question

我正在使用 spring boot 版本 - 2.0.6.RELEASE 和 spring cloud 版本 - Finchley.SR2

并且我已经创建了我的自定义网关过滤器来修改请求正文。

但是在使用 Flux 将请求正文转换为字符串时，我得到一个空字符串。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我相信它包含在 Spring Cloud Gateway 2.0.2 中，它是 Finchley 的一部分.

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);
    };
}