SpringMVC实现上传下载文件
本文实例为大家分享了SpringMVC实现上传下载文件的具体代码,供大家参考,具体内容如下
一、SpringMVC专门提供了CommonsMultipartResolver组件用于文件上传:
(1)maxUploadSize 文件最大限制,单位是byte
(2)maxInMemorySize 低于这个大小的文件暂存内存中
(3)defaultEncoding 默认编码utf-8
必须在spring-mvc.xml文件
<!-- (2)配置 MultipartResolver 实现文件上传 注意:id="multipartResolver"是固定写法 --> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <!-- 字符编码 --> <property name="defaultEncoding" value="utf-8"/> <!-- max size 10M --> <property name="maxUploadSize" value="10485760000"/> <!--内存中最大 4K --> <property name="maxInMemorySize" value="4096"/> </bean>
二、SpringMVC文件上传引入jar包
必须在配置Pom.xml文件
<!-- fileupload start --> <dependency> <groupId>commons-fileupload</groupId> <artifactId>commons-fileupload</artifactId> <version>1.3.1</version> </dependency> <dependency> <groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>2.4</version> </dependency> <!-- end -->
三、实现【单个文件】上传
(1)JSP页面必须放在WEB-INF下 upload1.jsp 必须添加enctype="multipart/form-data"
<body> <div style="margin: 0 auto; margin-top: 100px; background:snow"> <form method="post" action="upload1.html" name="form1" enctype="multipart/form-data"> <p> 照片:<input type="file" name="imagefile"> <input type="submit" value="上传" name="button1"> <br> </p> </form> </div>
(2) 写控制类 UploadController.java
@Controller public class UploadController { @RequestMapping("upload1") public String getUpload(@RequestParam("imagefile") MultipartFile imagefile, HttpServletRequest request) { // 获取上传的服务器路径 String pathString = request.getSession().getServletContext().getRealPath("/upload/"); // 获取文件 String fileName = imagefile.getOriginalFilename(); System.out.println(fileName); // 判断上传的路径是否存在 File file = new File(pathString); if (!file.exists()) { file.mkdirs(); } System.out.println("上传路径=" + pathString +"/"+ fileName); // 文件不存在 File targetFile = new File(pathString +"/"+ fileName); if (!targetFile.exists()) { try { targetFile.createNewFile(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } try { // 上传 imagefile.transferTo(targetFile); } catch (IllegalStateException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } //注意:/springmvc5/WEB-INF/jsp/http:/localhost:8888/springmvc5/upload/1.gif.jsp //返回文件,必须是重定向文件 return "redirect:http://localhost:8888/springmvc5/upload/" + fileName; } }
(3)效果
选择图片路径:
单击上传:
四、实现【多个文件】上传
(1)JSP页面(必须放在WEB-INF下) upload2.jsp 必须添加enctype="multipart/form-data"
<body> <div style="margin: 0 auto; margin-top: 100px; background:snow"> <form method="post" action="upload2.html" name="form1" enctype="multipart/form-data"> <p> 照片1:<input type="file" name="imagefile1"><p/> 照片2:<input type="file" name="imagefile2"><p/> <input type="submit" value="上传" name="button1"> <br> </p> </form> </div> </body>
(2) 写控制类 UploadController.java
@RequestMapping("upload2") public String getUpload2(HttpServletRequest request) { // 多文件上传 MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request; // 获得多个文件 Map<String, MultipartFile> map = multipartRequest.getFileMap(); // 获取上传的服务器路径 String pathString = request.getSession().getServletContext().getRealPath("/upload/"); // 判断上传的路径是否存在 File file1 = new File(pathString); if (!file1.exists()) { file1.mkdirs(); } // 获取文件 List<String> list = new ArrayList<String>(); // 遍历数据 for (MultipartFile file : map.values()) { String fileName = file.getOriginalFilename(); System.out.println("上传路径=" + pathString +"/"+ fileName); // 文件不存在 File targetFile = new File(pathString +"/"+ fileName); if (!targetFile.exists()) { try { targetFile.createNewFile(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } try { // 上传 file.transferTo(targetFile); // 保存路径 list.add("http://localhost:8888/springmvc5/upload/" + fileName); } catch (IllegalStateException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } // 保存每个上传的路径 request.setAttribute("files", list); return "showUpload"; //跳转到showUpload.jsp页面哦! }
注意:return "showUpload";是具体显示的页面;必须配置视图解析器在spring-mvc.xml文件中
<!--(1) spring 视图解析器 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" p:prefix="/WEB-INF/jsp/" p:suffix=".jsp"></bean>
(3)JSP页面: showUpload.jsp
<div style="margin: 0 auto; margin-top: 100px; background:snow"> <% List<String> list =(List<String>) request.getAttribute("files"); for(String str:list){ %> <a href="<%=str%>" rel="external nofollow" ><img src="<%=str%>" alt=""/></a> <%} %> </div>
(4)效果
单击上传:
查看上传到服务器的图片
五、下载图片
(1)JSP页面 login.jsp
<a href="download.html?fileName=08.gif" >下载图片</a><p/>
(2)控制类DownController
@Controller public class DownController { @RequestMapping("/download") public String download(@RequestParam String fileName, HttpServletRequest request, HttpServletResponse response) { // 设置响应编码 response.setContentType("text/html;charset=utf-8"); // 设置请求编码 try { request.setCharacterEncoding("utf-8"); } catch (UnsupportedEncodingException e) { // TODO Auto-generated catch block e.printStackTrace(); } // 字节流 BufferedInputStream bis=null; BufferedOutputStream bos=null; // 获取服务器的路径 String path = request.getSession().getServletContext().getRealPath("/upload/"); // 下载的路径 String downPath = path +"/"+ fileName; try { // 文件大小 long fileSize = new File(downPath).length(); //设置内容类型 response.setContentType("application/x-msdownload"); //设置头信息 response.setHeader("Content-disposition", "attachment; filename="+new String(fileName.getBytes("utf-8"),"ISO8859-1")); response.setHeader("Content-Length",String.valueOf(fileSize)); //字节流 bis = new BufferedInputStream(new FileInputStream(downPath)); bos= new BufferedOutputStream(response.getOutputStream()); //字节数组 byte[] by = new byte[2048]; // int length=0; //读取 while((length=bis.read(by,0,by.length))!=-1){ //写入 bos.write(by, 0, length); } } catch (Exception e) { // TODO: handle exception e.printStackTrace(); }finally{ //关闭连接 if(bis!=null){ try { bis.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } if(bos!=null){ try { bos.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } return null; } }
(3)效果
保存或打开如下:
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持我们。
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