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：

 import java.io.*;

 import javax.servlet.ServletException;
 import javax.servlet.http.*;

 public class hellohttp extends HttpServlet {

     //处理get请求
     //req用于获取客户端（浏览器）的信息
     //res用于向客户端（浏览器）返回信息
     public void doGet(HttpServletRequest req, HttpServletResponse res)
             throws ServletException, IOException {

         //业务逻辑
         try{
             PrintWriter pw=res.getWriter();
             pw.println("hello,http");
         }catch(Exception e){
             e.printStackTrace();
         }
     }
     //处理post请求
     //req用于获取客户端（浏览器）的信息
     //res用于向客户端（浏览器）返回信息
     public void doPost(HttpServletRequest req,HttpServletResponse res)
             throws ServletException,IOException
     {
         //合二为一，业务逻辑处理方式都一样
         this.doGet(req, res);
     }

     public void init() throws ServletException{
         // Put your code here
     }

     public void destroy() {
         super.destroy(); // Just puts "destroy" string in log
         // Put your code here
     }
 }