springmvc上传文件

SpringMVC文件上传

思路

SpringMvc的文件上传时通过MultipartResolver(Multipart解析器)处理的,对于MultipartResolver而言它只是一个接口,它有两个实现类

CommonsMultipartResolver:依赖于Apache下的jakarta Common FileUpload 项目解析Multipart请求,可以在Spring各个版本中使用,只是它要依赖于第三方包才得以实现,后面的案例中使用这个-
```
<dependency>
    <groupId>commons-fileupload</groupId>
    <artifactId>commons-fileupload</artifactId>
    <version>1.4</version>
</dependency>
```
StandardServletMultipartResolver:是Spring3.1版本后的产物,它依赖于Servlet3.0或者更高版本的实现,它不用依赖于第三方包

第一种实现基于CommonsMultipartResolver

在SpringMvc配置文件中配置MultipartResolver,"multipartResolver"是Spring约定好的名字不可以修改.

<bean class="org.springframework.web.multipart.commons.CommonsMultipartResolver" id="multipartResolver">
    <property name="defaultEncoding" value="utf-8"/>
    <property name="maxUploadSize" value="#{10*1024*1024}"/>
</bean>

上传文件表单

<form action="/test" enctype="multipart/form-data" method="post">
    头像<input type="file" name="headimg">
    <br>
    <input type="submit" value="提交">
</form>

处理请求的Controller

@RequestMapping(value = "/test",method = RequestMethod.POST)
public String test(@RequestParam("headimg") MultipartFile file) throws IOException {
    File file1 =new File("D:/"+file.getOriginalFilename());//创建file对象
    file.transferTo(file1);//将接受的文件存储
    return "success";
}

tomcat启动后测试就可以看到文件上传成功了

第二种基于StandardServletMultipartResolver

springmvc配置文件

<bean class="org.springframework.web.multipart.support.StandardServletMultipartResolver" id="multipartResolver">
</bean>

web.xml配置

<servlet>
    <servlet-name>dispatcherServlet</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:springmvc.xml</param-value>
    </init-param>
    <multipart-config>
        <location>D:/</location>
        <max-request-size>5242880</max-request-size>
        <file-size-threshold>20000000</file-size-threshold>
    </multipart-config>
</servlet>

然后写好表单和Controller,就可以测试了