SpringMVC-文件上传和下载
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文件上传和下载
1、添加框架支持，配置web.xml文件
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
<servlet>
<servlet-name>springmvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<filter>
<filter-name>encoding</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>utf-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>encoding</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>
2、配置applicationContext.xml文件
<?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:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://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">
<mvc:default-servlet-handler/>
<context:component-scan base-package="com.kuang.controller"/>
<!--配置注解驱动（含乱码处理）-->
<mvc:annotation-driven>
<mvc:message-converters register-defaults="true">
<bean class="org.springframework.http.converter.StringHttpMessageConverter">
<constructor-arg value="UTF-8"/>
</bean>
<bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
<property name="objectMapper">
<bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
<property name="failOnEmptyBeans" value="false"/>
</bean>
</property>
</bean>
</mvc:message-converters>
</mvc:annotation-driven>
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/jsp/"/>
<property name="suffix" value=".jsp"/>
</bean>
<!--文件上传的配置-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!--请求的编码格式，必须和jsp的pageEncoding属性一直，以便正确读取表单的内容，默认为ISO-8859-1 -->
<property name="defaultEncoding" value="utf-8"/>
<!--上传文件大小上限，单位为字节（10485760=10M）-->
<property name="maxUploadSize" value="10485760"/>
<property name="maxInMemorySize" value="40960"/>
</bean>
</beans>
3、创建Controller类实现上传
-
方法一
@RestController public class FileController @RequestMapping("/upload") public String fileUpload(@RequestParam("file")CommonsMultipartFile file , HttpServletRequest request) throws IOException // 获取文件名： file.getOriginalFilename(); String uploadFileName = file.getOriginalFilename(); // 如果文件名为空，直接回到首页 if ("".equals(uploadFileName)) return "redirect:index.jsp"; System.out.println("上传文件名：" + uploadFileName); // 上传路径保存设置 String path = request.getServletContext().getRealPath("/upload"); // 如果路径不存在，创建一个 File realPath = new File(path); if (!realPath.exists()) realPath.mkdir(); System.out.println("上传文件保存地址：" + realPath); InputStream is = file.getInputStream(); // 文件输入流 OutputStream os = new FileOutputStream(new File(realPath,uploadFileName)); // 文件输出流 // 读取写出 int len = 0; byte[] buffer = new byte[1024]; while ((len = is.read(buffer)) != -1) os.write(buffer,0,len); os.flush(); os.close(); is.close(); return "redirect:index.jsp"; -
方法二：
@RestController public class FileController @RequestMapping("/upload2") public String fileUpload2(@RequestParam("file")CommonsMultipartFile file , HttpServletRequest request) throws IOException // 上传路径保存设置 String path = request.getServletContext().getRealPath("/upload"); File realPath = new File(path); if (!realPath.exists()) realPath.mkdir(); // 上传文件地址 System.out.println("上传文件保存地址：" + realPath); // 通过CommonsMultipatrFile的方法直接写文件（注意这个时候） file.transferTo(new File(realPath + "/" + file.getOriginalFilename())); return "redirect:/index.jsp";
4、配置Controller类实现下载
@RestController
public class FileController
@RequestMapping(value = "/download")
public String downloads(HttpServletResponse response,HttpServletRequest request) throws IOException
System.out.println("进入方法");
// 要下载的图片地址
String path = request.getServletContext().getRealPath(("/upload"));
String fileName = "xq.jpg";
// 1、设置response响应头
response.reset(); // 设置页面不缓存，清空buffer
response.setCharacterEncoding("UTF-8"); // 字符编码
response.setContentType("multipart/form-data"); // 二进制传出数据
// 设置响应头
response.setHeader("Content-Disposition",
"attachment;fileName=" + URLEncoder.encode(fileName,"UTF-8"));
File file = new File(path,fileName);
// 2、读取文件--输入流
InputStream input = new FileInputStream(file);
// 3、写出文件--输出流
OutputStream out = response.getOutputStream();
byte[] buff = new byte[1024];
int index = 0;
// 4、执行 写出操作
while ((index = input.read(buff)) != -1)
out.write(buff,0,index);
out.flush();
out.close();
input.close();
return null;
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