java下载文件

前台用a标签访问，不要用ajax，不然没反应

 @RequestMapping(value="/download",method = RequestMethod.GET, produces = "text/html;charset=utf-8")
    public void download(
    		@RequestParam(value="path",required=false) String path,
    		@RequestParam(value="fileName",required=false) String fileName,
    		HttpServletRequest req, HttpServletResponse resp
    		) { 
        try {
			
        	req.setCharacterEncoding("UTF-8");
            //第一步：设置响应类型
            resp.setContentType("application/force-download");//应用程序强制下载
            //第二读取文件
           // String path = getServletContext().getRealPath("/up/"+name);
            InputStream in = new FileInputStream(path);
            //设置响应头，对文件进行url编码
            fileName = URLEncoder.encode(fileName, "UTF-8");
            resp.setHeader("Content-Disposition", "attachment;filename="+fileName);   
            resp.setContentLength(in.available());
            
            //第三步：老套路，开始copy
            OutputStream out = resp.getOutputStream();
            byte[] b = new byte[1024];
            int len = 0;
            while((len = in.read(b))!=-1){
              out.write(b, 0, len);
            }
            out.flush();
            out.close();
            in.close();
			
		} catch (Exception e) {
			e.printStackTrace();
		}
    } 

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