gateway异常：DefaultDataBuffer cannot be cast to org.springframework.core.io.buffer.NettyDataBuffer

启动gateway后

出现java.lang.ClassCastException: org.springframework.core.io.buffer.DefaultDataBufferFactory cannot be cast to org.springframework.core.io.buffer.NettyDataBufferFactory

导致原因是：springcloud的gateway使用的是webflux,默认使用netty,所以从依赖中排除 tomcat相关的依赖 ，就可以了

        <!--web-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-webmvc</artifactId>
                </exclusion>
                <exclusion>
                    <artifactId>spring-boot-starter-tomcat</artifactId>
                    <groupId>org.springframework.boot</groupId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>