springboot文件上传抛异常：org.apache.catalina.core.ApplicationPart must implement java.io.Serializable

解决方法：

1、启动类加注解：

@EnableAutoConfiguration(exclude = {MultipartAutoConfiguration.class})

2、写上传文件配置类：

import org.springframework.boot.SpringBootConfiguration;
import org.springframework.context.annotation.Bean;
import org.springframework.web.multipart.MultipartResolver;
import org.springframework.web.multipart.commons.CommonsMultipartResolver;

@SpringBootConfiguration
public class FileUpLoadConfig {

    //显示声明CommonsMultipartResolver为mutipartResolver
    @Bean(name = "multipartResolver")
    public MultipartResolver multipartResolver(){
        CommonsMultipartResolver resolver = new CommonsMultipartResolver();
        resolver.setDefaultEncoding("UTF-8");
        resolver.setResolveLazily(true);//resolveLazily属性启用是为了推迟文件解析，以在在UploadAction中捕获文件大小异常
        resolver.setMaxInMemorySize(40960);
        resolver.setMaxUploadSize(50*1024*1024);//上传文件大小 50M 50*1024*1024
        return resolver;
    }
}