上传文件的详解
创建控制层，上传文件：
@Controller
public class MyController {
@PostMapping("/myUpload")
public String upload(HttpServletRequest request) {
String upload = request.getServletContext().getRealPath("/upload");
File file = new File(upload);
if (!file.exists()) file.mkdirs();
try {
Part uploadFile = request.getPart("file");
String submittedFileName = uploadFile.getSubmittedFileName();
uploadFile.write(upload+new Date().getTime()+submittedFileName);
} catch (IOException e) {
throw new RuntimeException(e);
} catch (ServletException e) {
throw new RuntimeException(e);
}
request.setAttribute("msg","上传成功");
return "forward:/pages/success.jsp";
}
}
编写上传成功的页面：
<html>
<head>
<title>Title</title>
</head>
<body>
<h1>success</h1>
${msg}
</form>
</body>
</html>
web层添加文件上传配置【添加在中央处理器加载的servlet】
<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:springwebmvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
<multipart-config>
<max-file-size>20480</max-file-size>
<!--文件大小阈值，当大于这个阈值时将写入到磁盘，否则在内存中。默认值为0-->
<file-size-threshold>1048576</file-size-threshold>
</multipart-config>
</servlet>
<servlet-mapping>
<servlet-name>dispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
上面的<multipart-config>相当于在mvc.xml里面配置了：
<!--文件上传解析器 id固定为multipartResolver-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"/>
配置mvc：
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">
<context:component-scan base-package="com.java.controller"/>
<!--开启mvc注解驱动-->
<mvc:annotation-driven/>
<!--配置静态资源访问处理器-->
<mvc:default-servlet-handler/>
<!--视图解析器-->
<!--<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"/>-->
</beans>