文件上传与下载

一、单个文件上传和下载
二、下载多个文件时打成zip压缩包

使用的是Apache的upload jar包

        <!-- 上传组件包 -->
<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>
<dependency>
    <groupId>commons-codec</groupId>
    <artifactId>commons-codec</artifactId>
    <version>1.9</version>
</dependency>

单个文件上传

@RequestMapping("/upload")
    protected void Upload(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        // 1.解析器解析request的上下文
        CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver(
                request.getSession().getServletContext());

        // 2.先判断request中是否包涵multipart类型的数据(即：判断 request 是否有文件上传,即多部分请求 )
        if (multipartResolver.isMultipart(request)) {
            //3. 再将request中的数据转化成multipart类型的数据（即： 转换成多部分request  ）
            MultipartHttpServletRequest multiRequest = (MultipartHttpServletRequest) request;
            // 4.取得request中的所有文件并将其存到硬盘中
            Iterator<String> iter = multiRequest.getFileNames();
            while (iter.hasNext()) {
                // 5.取得上传文件
                MultipartFile file = multiRequest.getFile((String) iter.next());
                // 如果名称不为“”,说明该文件存在，否则说明该文件不存在
                if (file != null) {
                    // 6.取得当前上传文件的文件名称
                    String fileName = file.getOriginalFilename();
                    if(fileName.trim() != "") {
                        // 7.定义上传路径
                        String path = "D:/" + fileName;
                        //8.新建文件
                        File localFile = new File(path);
                        // 9.写文件到本地
                        file.transferTo(localFile);
                    }
                }
            }
        }
    }

单个文件下载（在Java里写下载代码，可以做下载限速和权限检查）

@RequestMapping("/download")
   protected ResponseEntity<byte[]> Download() throws IOException {  
       File file = new File("D:/2.txt");
       String fileName = "2.txt"; 
       String dfileName = new String(fileName.getBytes("gb2312"), "iso8859-1");
       HttpHeaders headers = new HttpHeaders();
       headers.setContentDispositionFormData("attachment", dfileName);
       headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
       /**
        * HttpStatus.OK 和 HttpStatus.CREATE 区别
        * 使用后者的话 在ie11里无法下载
        */
       ResponseEntity<byte[]> re = new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(file), 
              headers, HttpStatus.OK);
      return re;
   }

普通单个文件的下载方法：（没有试验过）

@RequestMapping(value = "/downloadFile")
@ResponseBody
public void downloadFile (HttpServletResponse response) {
      OutputStream os  = null;
      try {
　　　os = response.getOutputStream();
　　　File file = new File("D:/javaweb/demo.txt");
　　　// Spring工具获取项目resources里的文件
　　　File file2 = ResourceUtils.getFile("classpath:shell/sinit.sh");
        if(!file.exists()){
　　　　　　return;
　　　}
        response.reset();
        response.setHeader("Content-Disposition", "attachment;filename=demo.txt");
        response.setContentType("application/octet-stream; charset=utf-8");
        os.write(FileUtils.readFileToByteArray(file));
    } catch (Exception e) {
        e.printStackTrace();
    }finally{

下载文件>=1个时打成zip压缩包

/**
 * 打包压缩下载文件
 */
@RequestMapping("/downLoadZipFile")
public void downLoadZipFile( HttpServletResponse response) throws IOException{
    String zipName = "myfile.zip";
    response.setContentType("APPLICATION/OCTET-STREAM");  
    response.setHeader("Content-Disposition","attachment; filename="+zipName);
    ZipOutputStream out = new ZipOutputStream(response.getOutputStream());
    List<FileEntry> fileList = new ArrayList<FileEntry>();
    FileEntry file = new FileEntry();
    file.setPathName("D:/1.xlsx");
    file.setName("1.xlsx");
    fileList.add(file);
    FileEntry file1 = new FileEntry();
    file1.setPathName("D:/t.xlsx");
    file1.setName("t.xlsx");
    fileList.add(file1);
 
    try {
        for(Iterator<FileEntry> it = fileList.iterator();it.hasNext();){
            FileEntry file2 = it.next();
            ZipUtils.doCompress(file2.getPathName(), out);
            response.flushBuffer();
        }
    } catch (Exception e) {
        e.printStackTrace();
    }finally{
        out.close();
    }
}