servlet三種實現方式之三通過繼承HttpServlet開發servlet

servlet有三種實現方式：

1.實現servlet接口

2.繼承GenericServlet

3.通過繼承HttpServlet開發servlet

 

第三種：

 

import java.io.*;

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


public class hellohttp extends HttpServlet {

    //處理get請求
    //req用於獲取客戶端（瀏覽器）的信息
    //res用於向客戶端（瀏覽器）返回信息
    public void doGet(HttpServletRequest req, HttpServletResponse res)
            throws ServletException, IOException {
        
        //業務邏輯
        try{
            PrintWriter pw=res.getWriter();
            pw.println("hello,http");
        }catch(Exception e){
            e.printStackTrace();
        }
    }
    //處理post請求
    //req用於獲取客戶端（瀏覽器）的信息
    //res用於向客戶端（瀏覽器）返回信息
    public void doPost(HttpServletRequest req,HttpServletResponse res)
            throws ServletException,IOException
    {
        //合二為一，業務邏輯處理方式都一樣
        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
    }
}