文件上传失败原因之一

 //文件上传配置
    @Bean
    public CommonsMultipartResolver multipartResolver() {
        CommonsMultipartResolver commonsMultipartResolver = new CommonsMultipartResolver();
        commonsMultipartResolver.setMaxUploadSize(104857600);
        commonsMultipartResolver.setMaxInMemorySize(4096);
        commonsMultipartResolver.setDefaultEncoding("utf-8");
        return commonsMultipartResolver;
    }

方法名字必须为

multipartResolver

不可以为CommonMultipartResolver