servlet三种实现方式之三通过继承HttpServlet开发servlet

servlet有三种实现方式：

1.实现servlet接口

2.继承GenericServlet

3.通过继承HttpServlet开发servlet

 

第三种：

 

 1 import java.io.*;

 2 

 3 import javax.servlet.ServletException;

 4 import javax.servlet.http.*;

 5 

 6 

 7 public class hellohttp extends HttpServlet {

 8 

 9     //处理get请求

10     //req用于获取客户端（浏览器）的信息

11     //res用于向客户端（浏览器）返回信息

12     public void doGet(HttpServletRequest req, HttpServletResponse res)

13             throws ServletException, IOException {

14         

15         //业务逻辑

16         try{

17             PrintWriter pw=res.getWriter();

18             pw.println("hello,http");

19         }catch(Exception e){

20             e.printStackTrace();

21         }

22     }

23     //处理post请求

24     //req用于获取客户端（浏览器）的信息

25     //res用于向客户端（浏览器）返回信息

26     public void doPost(HttpServletRequest req,HttpServletResponse res)

27             throws ServletException,IOException

28     {

29         //合二为一，业务逻辑处理方式都一样

30         this.doGet(req, res);

31     }

32 

33     public void init() throws ServletException{

34         // Put your code here

35     }

36 

37     public void destroy() {

38         super.destroy(); // Just puts "destroy" string in log

39         // Put your code here

40     }

41 }