如何读取和修改spring云网关筛选器中的请求体？有人能帮我吗？

import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
import org.springframework.stereotype.Component;

@Component
public class CustomFilterFactory extends AbstractGatewayFilterFactory<CustomFilterFactory.Config> {

    public CustomFilterFactory() {
        super(Config.class);
    }

    @Override
    public GatewayFilter apply(Config config) {
        return (exchange, chain) -> {
            // 读取请求体
            ServerHttpRequest request = exchange.getRequest();
            Flux<DataBuffer> body = request.getBody();
            // 处理请求体
            // ...

            // 修改请求体
            // ...

            // 继续处理请求链
            return chain.filter(exchange);
        };
    }

    public static class Config {
        // 配置参数（如果需要）
    }
}