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
    }
}