java spring导出数据为txt文件供页面下载

@RequestMapping("exportTerminalKey.do")
	public void exportTerminalKey(HttpServletRequest request, HttpServletResponse response) throws Exception {
		
		SerUser serUser = GlobalThreadLocal.getSerUserInfo();
		
		String filepath = "宝付_"+serUser.getMerchantName()+"_终端.txt";
		response.reset();
	    response.setContentType("application/octet-stream");
	    String fileName= URLDecoder.decode(filepath,"utf-8");
	    java.net.URLEncoder.encode(fileName, "utf-8");
	    response.addHeader("Content-Disposition","attachment;"+ "filename=\"" +URLEncoder.encode(fileName, "utf-8") + "\"");
		
		List<Terminal> terminalList = terminalService.getTerminalList(serUser.getMemberId());
		StringBuilder sb = new StringBuilder("会员号,终端号,密钥,终端名称\r\n");
		if(terminalList!=null&&terminalList.size()>0){
			for(Terminal t:terminalList){
				sb.append(t.getMember().getId()+","+t.getId()+","+t.getKeyContent()+","+t.getName()+"\r\n");
			}
		}
		BufferedOutputStream output = null;
	    BufferedInputStream input = null;
	    OutputStream os =null;
	    try{
	    	os = response.getOutputStream();
            byte[] byt = sb.toString().getBytes();
            os.write(byt);
	    }catch(Exception e){
	    	logger.error("商户("+serUser.getAccountName()+")导出终端密钥出错", e);
	    }finally{
	    	os.flush();
	    	os.close();
	        if(input!=null){
	        	input.close();
	        }
	        if(output!=null){
	        	output.close();
	        }
	    }
	    return;
	}