java之spring mvc之文件上传

目录结构如下：

注意，下面说的配置文件，一般都是值的src下的配置文件，即mvc.xml。如果是web.xml，则直接说 web.xml

1. 文件上传的注意点

表单必须是post提交，必须将 enctype 设置为 “multipart/form-data”,

使用 commons-fileupload 提交文件，需要添加 commons-fileupload 和 commons-io 的 jar 包。

2.Jsp 页面

<form action="file/upload.do" method="post" enctype="multipart/form-data">
文件:<input type="file" name="file"/><input type="submit" value="上传"/>
</form>
</body>

3.Controller类

@Controller
//窄化
@RequestMapping("/file")
public class UploadController {
    @RequestMapping("/upload.do")
    public String upload(@RequestParam("file")CommonsMultipartFile file,HttpServletRequest req) throws Exception{
        String path=req.getServletContext().getRealPath("/upload");
        //获取文件名
        String fileName=file.getOriginalFilename();
        InputStream is = file.getInputStream();
        OutputStream os = new FileOutputStream(new File(path,fileName));
        byte[] buffer = new byte[400];
        int len=0;
        while((len=is.read(buffer))!=-1){
            os.write(buffer, 0, len);
        }
        os.close();
        is.close();
        return "redirect:/index.jsp";
    }
}

4. 在配置 文件中添加 multipartResolver

<!-- 文件上传配置 -->
    <bean id="multipartResolver"
        class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <property name="maxUploadSize" value="1000000"/>
    </bean>

附录：

附一，这里附上mvc.xml的文件内容

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:p="http://www.springframework.org/schema/p"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">
    <!-- 注解开发适配器 -->
    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"/>
    <!-- 配置视图解析器 -->
    <bean id="viewResolver"
        class="org.springframework.web.servlet.view.UrlBasedViewResolver">
        <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
           <!-- 为响应的视图名称加上前缀  -->
        <property name="prefix" value="/WEB-INF/jsp/"/>
        <!-- 为响应的视图名称加上后缀  -->
        <property name="suffix" value=".jsp"/>
    </bean>
    <!-- 文件上传配置 -->
    <bean id="multipartResolver"
        class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <property name="maxUploadSize" value="1000000"/>
    </bean>
    <!-- 扫描注解类 -->
    <context:component-scan base-package="cn.sxt.controller"/>
</beans>

这里再附上 WebContent/WEB-INF/ 下的 web.xml 文件内容

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
  <display-name>01springmvc_helloworld</display-name>
  <servlet>
      <servlet-name>springmvc</servlet-name>
      <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
      <!-- 改变springmvc配置文件的路径及名称 -->
      <init-param>
          <param-name>contextConfigLocation</param-name>
          <param-value>classpath:mvc.xml</param-value>
      </init-param>
  </servlet>
  <servlet-mapping>
      <servlet-name>springmvc</servlet-name>
      <url-pattern>*.do</url-pattern>
  </servlet-mapping>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
</web-app>

原文地址：https://www.cnblogs.com/Vincent-yuan/p/11278749.html