尝试上载文件时，必需的MultipartFile参数“file”不存在错误

Question

简单示例：jsp中的表单

<form method="post" action="/asd" enctype="multipart/form-data">
    <input type="file" class="file" name="file"/>
    <input type="hidden" name="${_csrf.parameterName}" value="${_csrf.token}"/>    
    <input type="submit" value="Upload">    
</form>

我的控制器的方法

@RequestMapping(value = "/asd", method = RequestMethod.POST)
    public String handleFileUpload(
            @RequestParam("file") MultipartFile file){    
        System.out.print(file);    
        return "string";    
    }

我的上下文xml文件

 <bean id="multipartResolver"
          class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <!-- max upload size in bytes -->
        <property name="maxUploadSize" value="20971520" /> <!-- 20MB -->

        <!-- max size of file in memory (in bytes) -->
        <property name="maxInMemorySize" value="1048576" /> <!-- 1MB -->

    </bean>

<dependency>
      <groupId>commons-fileupload</groupId>
      <artifactId>commons-fileupload</artifactId>
      <version>1.3.1</version> <!-- makesure correct version here -->
    </dependency>
    <dependency>
      <groupId>commons-io</groupId>
      <artifactId>commons-io</artifactId>
      <version>2.4</version>
    </dependency>

<Context reloadable="true" allowCasualMultipartParsing="true">

描述由于被认为是客户端错误（例如，错误的请求语法、无效的请求消息帧或欺骗性的请求路由），服务器无法或不会处理请求。

Apache Tomcat/8.5.12

Answer 1

试试这个,

在web.xml文件中添加贝娄过滤器

web.xml

<!-- Support for File Upload And Download -->
 <filter>
<display-name>springMultipartFilter</display-name>
<filter-name>springMultipartFilter</filter-name>
<filter- class>org.springframework.web.multipart.support.MultipartFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>springMultipartFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

<!-- Support For File Upload And Download -->
<bean id="filterMultipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
    <property name="maxUploadSize" value="100000000" />

</bean>