SpringMVC实现上传和下载
package com.pk.web.controller; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.multipart.MultipartFile; import org.springframework.web.multipart.MultipartHttpServletRequest; import org.springframework.web.multipart.commons.CommonsMultipartResolver; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.*; import java.text.SimpleDateFormat; import java.util.Date; import java.util.Iterator; /** * Created by Administrator on 2014/9/5. */ @Controller @RequestMapping("file") public class UploadController { @RequestMapping("/upload.do") public String upload(HttpServletRequest request, HttpServletResponse response) throws IOException { // 这里我用到了jar包 CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver( request.getSession().getServletContext()); if (multipartResolver.isMultipart(request)) { MultipartHttpServletRequest multiRequest = (MultipartHttpServletRequest) request; Iterator<String> iter = multiRequest.getFileNames(); while (iter.hasNext()) { MultipartFile file = multiRequest.getFile((String) iter.next()); if (file != null) { String fileName = file.getOriginalFilename(); String path1 = Thread.currentThread() .getContextClassLoader().getResource("").getPath() + "download" + File.separator; // 下面的加的日期是为了防止上传的名字一样 String path = path1 + new SimpleDateFormat("yyyyMMddHHmmss") .format(new Date()) + fileName; File localFile = new File(path); file.transferTo(localFile); } } } return "uploadSuccess"; } @RequestMapping("/toUpload.do") public String toUpload() { return "upload"; } @RequestMapping("/download") public String download(String fileName, HttpServletRequest request, HttpServletResponse response) { response.setCharacterEncoding("utf-8"); response.setContentType("multipart/form-data"); response.setHeader("Content-Disposition", "attachment;fileName=" + fileName); try { String path = Thread.currentThread().getContextClassLoader() .getResource("").getPath() + "download";//这个download目录为啥建立在classes下的 InputStream inputStream = new FileInputStream(new File(path + File.separator + fileName)); OutputStream os = response.getOutputStream(); byte[] b = new byte[2048]; int length; while ((length = inputStream.read(b)) > 0) { os.write(b, 0, length); } // 这里主要关闭。 os.close(); inputStream.close(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } // 返回值要注意,要不然就出现下面这句错误! //java+getOutputStream() has already been called for this response return null; } }
还有 上传 配置文件注意
<!-- mvc注解驱动 -->
<mvc:annotation-driven/>
<!-- 扫描器已经有了上面这个mvc注解驱动的功能了,所有不需要了 -->
<context:component-scan base-package="com.pk.web.controller" />
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<property name="defaultEncoding" value="utf-8" />
<property name="maxUploadSize" value="104857600"/>
<property name="maxInMemorySize" value="4096"/>
</bean>
<!-- 前缀+ viewName +后缀 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<!-- webroot到某一指定的文件夹的路径 -->
<property name="prefix" value="/WEB-INF/jsp/"></property>
<!-- 自己在你的 /WEB-INF/jsp下建立给jsp见面吧。或者该我上面的配置 -->
<!-- 视图名称的后缀 -->
<property name="suffix" value=".jsp"></property>
</bean>
这里是html 点击下载,这里就写死了(你可以修改成你自己放的文件)。可以修改的。
<a href="file/download.do?fileName=map.txt">下载1 </a><br />
下面这里是上传代码
<form action="file/upload.do" method="post" enctype="multipart/form-data">
选择文件<input type="file" name="file">
<input type="submit" value="上传">
</form>
web.xml 配置文件
<servlet>
<servlet-name>springmvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<filter>
<filter-name>encodingFilter</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>
<init-param>
<param-name>forceEncoding</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>encodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<!-- struts习惯使用/*,在springmvc不管用 -->
<url-pattern>*.do</url-pattern>
</servlet-mapping>
每个方法都返回的是一个ActionForward对象,而response是ActionForward对象参数,所以就会使response冲突!
所以处理上传的action返回null就可以了
最终我把action里的最后 “return SUCCESS ” 改成了 “return null ” 成功了 !!!
jar 包在 oschina 这里不知道怎么上传过去给下载的。。同学们自己网上找吧!
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