public void doPost(HttpServletRequest request,HttpServletResponse response) throws IOException,ServletException {    	response.setContentType("text;html;charset=utf-8");    	DataOutputStream output=new DataOutputStream(response.getOutputStream());    	String imagePath = "D://home.jpg";    	//http://localhost:8080/HelloWorldServlet/MyFirstServlet?username=xxxx&password=111    	  String username=request.getParameter("username");    	  String password=request.getParameter("password");    	  System.out.println("username="+username);    	  System.out.println("password="+password);    	  System.out.println("servlet test success....");    	  response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode("home.jpg", "UTF-8"));       	  response.setHeader("Content-Type", "application/octet-stream");     	      	  FileInputStream fis = new FileInputStream(imagePath);          int size =fis.available(); //得到文件大小             byte data[]=new byte[size];             fis.read(data);  //读数据             fis.close();     	            output.write(data);          output.close();    }