spring cloud gateway response的读取和修改

核心思路是通过ModifyResponseBodyGatewayFilterFactory来实现

官方文档中，ModifyResponseBodyGatewayFilterFactory的使用方法没有详细描述

实际使用时，配置如下：

spring:
  cloud:
    gateway:
      routes:
        - id: echo
          order: -1
          uri: lb://demo
          filters:
            - name: ModifyResponseBody
              args:
                inClass: '#{T(String)}'
                outClass: '#{T(String)}'
                rewriteFunction: '#{@handleEchoResponse}'
          predicates:
            - Method=POST
            - Path=/echo

还需要实现RewriteFunction，在实现中可以读取并修改response body

@Slf4j
@Component
public class HandleEchoResponse implements RewriteFunction {

    @Override
    public Publisher apply(ServerWebExchange exchange, String body) {
        if (StrUtil.isNotBlank(body)) {
            log.debug("response body:{}", body);
        }
        return Mono.just(body);
    }
}