spring mvc下载文件

这里介绍两种方式，一种是从服务器下载，一种是从网络上下载

一、从服务器下载

这里path的格式为：D:\testFile\a.jpg，下载后保存在浏览器的下载位置

 @RequestMapping("download")    
 public ResponseEntity<byte[]> download(String path) throws IOException {    
	       // File file=new File(path);  
	        String names[] = path.split("\\.");
	        String name = DateUtil.getCurrentDate("yyyyMMddHHmmss.") + names[names.length-1];
	        
	        HttpHeaders headers = new HttpHeaders();    
	        String fileName=new String(name.getBytes("UTF-8"),"iso-8859-1");//为了解决中文名称乱码问题  
	        headers.setContentDispositionFormData("attachment", fileName);   
	        headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);   
	        File file = FileUtils.toFile(new URL(path));
	        return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray( file),    
	                                          headers, HttpStatus.CREATED);    
 }  

二、从网络上下载

这里path的格式为：http://xxx.com/xxx/s_2015072218115087481.jpg

   @RequestMapping("download")    
   public void download(String path,HttpServletResponse response) throws IOException {    
	     byte[] btImg = getImageFromNetByUrl(path);  
	     String fileName = "";
	     if(null != btImg && btImg.length > 0){  
	     String names[] = path.split("\\.");
	     fileName = DateUtil.getCurrentDate("yyyyMMddHHmmss.") + names[names.length-1];
	     writeImageToDisk(btImg, fileName);
	     fileName = URLEncoder.encode(fileName, "UTF-8");  
	     response.reset();  
	     response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");  
	     response.addHeader("Content-Length", "" + btImg.length);  
	     response.setContentType("application/octet-stream;charset=UTF-8");  
	     OutputStream outputStream = new BufferedOutputStream(response.getOutputStream());  
	     outputStream.write(btImg);  
	     outputStream.flush();  
	     outputStream.close();  
      }
			   
		       
   
  /** 
	     * 根据地址获得数据的字节流 
	     * @param strUrl 网络连接地址 
	     * @return 
	     */  
    public static byte[] getImageFromNetByUrl(String strUrl){  
    <span style="white-space:pre">	</span>try {  
	         URL url = new URL(strUrl);  
	            HttpURLConnection conn = (HttpURLConnection)url.openConnection();  
	            conn.setRequestMethod("GET");  
	            conn.setConnectTimeout(5 * 1000);  
	            InputStream inStream = conn.getInputStream();//通过输入流获取图片数据  
	            byte[] btImg = readInputStream(inStream);//得到图片的二进制数据  
	            return btImg;  
	        } catch (Exception e) {  
	            e.printStackTrace();  
	        }  
	        return null;  
	    }  
    /** 
	     * 从输入流中获取数据 
	     * @param inStream 输入流 
	     * @return 
	     * @throws Exception 
	     */  
	    public static byte[] readInputStream(InputStream inStream) throws Exception{  
	        ByteArrayOutputStream outStream = new ByteArrayOutputStream();  
	        byte[] buffer = new byte[1024];  
	        int len = 0;  
	        while( (len=inStream.read(buffer)) != -1 ){  
	            outStream.write(buffer, 0, len);  
	        }  
	        inStream.close();  
	        return outStream.toByteArray();  
	    }  

此方法可以下载资源到指定位置

  /** 
	     * 将图片写入到磁盘 
	     * @param img 图片数据流 
	     * @param fileName 文件保存时的名称 
	     */  
	    public static void writeImageToDisk(byte[] img, String fileName){  
	        try {  
	            File file = new File("D:\\" + fileName);  
	            FileOutputStream fops = new FileOutputStream(file);  
	            fops.write(img);  
	            fops.flush();  
	            fops.close();  
	            System.out.println("图片已经写入到C盘");  
	        } catch (Exception e) {  
	            e.printStackTrace();  
	        }  
	    }