1.前者只依赖@Controller(“/abc”)注解进行识别，后者是依赖Controller和ReqestMapping注解进行识别。
2.前者的类对象是由Servlet接口派生，后者是无派生关系的普通类。

@Controller
@RequestMapping("/demo")
public class DemoController {

	@RequestMapping("/findall")
	public String handleList(Model model) {
		logger.info("demo02  handleList");
		List list = demoService.findAll();
		model.addAttribute("results", list);
		return "demo";
	}
}

@Controller("/demo_servlet2")
public class Demo2Servlet extends HttpServlet {	
	@PostConstruct  //init-method="init"
	@Override
	public void init() throws ServletException {
		// TODO Auto-generated method stub
		logger.info("Demo2Servlet init start");		
		
		logger.info("Demo2Servlet init end");
	}

	@RequestMapping("/findall")
	public String handleList(Model model) {
		logger.info("demo02  handleList");
		return "demo";
	}

	@Override
	protected void service(HttpServletRequest req, HttpServletResponse response)
			throws ServletException, IOException {
		// TODO Auto-generated method stub

		logger.info("Demo2Servlet service start");

		response.setContentType(CONTENT_TYPE);
		response.setHeader("Pragma", "No-cache");
		response.setHeader("Cache-Control", "no-cache");
		response.setDateHeader("Expires", 0);
		String result = demoService.getById(1l).getName();
		//Integer.valueOf(result); //测试异常显示页面
		PrintWriter out = response.getWriter();
		out.println("");
		out.println("\n");
		out.println("" + result + "\n");
		out.println("\n");

		out.flush();
		out.close();

		logger.info("Demo2Servlet service end");
	}

	@PreDestroy //destroy-method="destroy"
	@Override
	public void destroy() {
		// TODO Auto-generated method stub
		logger.info("Demo2Servlet destroy start");
		
		logger.info("Demo2Servlet destroy end");
	}
	
}