准备工作
Spring Web MVC也是使用Apache的common-fileupload,因此要在lib里面添加如下的jar包:
commons-fileupload-1.2.2.jar、commons-io-2.4.jar
为了处理中文文件名称的上传下载,把前面HelloWorld讲过的filter配置上
在Spring的配置文件中,配置处理文件上传的bean,如下:
<bean id= "multipartResolver" class= "org.springframework.web.multipart.commons.CommonsMultipartResolver "> <property name= "maxUploadSize" value= "104857600"/> </bean>
配置上就好了,Spring会自动找的
文件上传示例,先看Controller部分,这里只是一个最基本的演示:
@Controller @RequestMapping(value = "/fileope") public class FileUploadController { @RequestMapping(value = "upload", method = RequestMethod.POST) public String upload( HttpServletRequest request, @RequestParam(value = "myFile", required = false) MultipartFile[] files) { try { for(int i=0;i<files.length;i++){ FileUploadUtils.upload(request, files[i]); } } catch (Exception e) { e.printStackTrace(); } return "success"; } } 对应使用的FileUploadUtils: public class FileUploadUtils { //默认大小 50M public static final long DEFAULT_MAX_SIZE = 52428800; //默认上传的地址 public static String defaultBaseDir = "upload"; public static final String upload(HttpServletRequest request, MultipartFile file)throws Exception{ String filename = extractFilename(file, defaultBaseDir); File desc = getAbsoluteFile(extractUploadDir(request), filename); file.transferTo(desc); return filename; } private static final File getAbsoluteFile(String uploadDir, String filename) throws IOException { if(uploadDir.endsWith("/")) { uploadDir = uploadDir.substring(0, uploadDir.length() - 1); } if(filename.startsWith("/")) { filename = filename.substring(0, uploadDir.length() - 1); } File desc = new File(uploadDir + "/" + filename); if(!desc.getParentFile().exists()) { desc.getParentFile().mkdirs(); } if(!desc.exists()) { desc.createNewFile(); } return desc; } public static final String extractFilename(MultipartFile file, String baseDir) throws UnsupportedEncodingException { String filename = file.getOriginalFilename(); int slashIndex = filename.indexOf("/"); if (slashIndex >= 0) { filename = filename.substring(slashIndex + 1); } filename = baseDir + "/" + filename; return filename; } public static final String extractUploadDir(HttpServletRequest request) { return request.getServletContext().getRealPath("/"); } }
上传的示例页面
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <form action="/mvcexample/fileope/upload" method="post" enctype="multipart/form-data"> file1:<input type="file" name="myFile"/> <br> file2:<input type="file" name="myFile"/> <br> <input type="submit" value="上传"> </form>
文件下载
下载的示例Controller的方法
@RequestMapping(value = "download", method = RequestMethod.GET) public static void download(HttpServletRequest request, HttpServletResponse response, String fileName) throws Exception { response.setContentType("text/html;charset=UTF-8"); request.setCharacterEncoding("UTF-8"); BufferedInputStream bis = null; BufferedOutputStream bos = null; String newFileName = new String(fileName.getBytes("ISO8859-1"),"UTF-8"); String ctxPath = request.getSession().getServletContext() .getRealPath("/") + FileUploadUtils.defaultBaseDir; String downLoadPath = ctxPath +"/"+ newFileName; long fileLength = new File(downLoadPath).length(); response.setHeader("Content-disposition", "attachment; filename=" + new String(newFileName.getBytes("gb2312"), "ISO8859-1")); response.setHeader("Content-Length", String.valueOf(fileLength)); bis = new BufferedInputStream(new FileInputStream(downLoadPath)); bos = new BufferedOutputStream(response.getOutputStream()); byte[] buff = new byte[2048]; int bytesRead; while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) { bos.write(buff, 0, bytesRead); } bis.close(); bos.close(); }