Unit01： Servlet基础 、 HTTP协议

package web;

import java.io.IOException;
import java.io.PrintWriter;
import java.text.SimpleDateFormat;
import java.util.Date;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class TimeServlet extends HttpServlet {

    @Override
    protected void service(
        HttpServletRequest req, 
        HttpServletResponse res) throws ServletException, IOException {
        //1.使用request接收请求数据
        //1.1请求行
        System.out.println(
            "请求方式:"+req.getMethod());
        System.out.println(
            "访问路径:"+req.getServletPath());
        System.out.println(
            "协议类型:"+req.getProtocol());
        //1.2消息头
        //1.3实体内容
        
        //2.使用response发送响应数据
        
        //获取服务器时间
        Date date = new Date();
        SimpleDateFormat sdf = 
            new SimpleDateFormat("HH:mm:ss");
        String now = sdf.format(date);
        //告诉浏览器发送给它的是网页
        res.setContentType("text/html");
        //获取writer
        PrintWriter out = res.getWriter();
        //输出网页的内容(偷懒少写点)
        out.println("<p>"+now+"</p>");
        //关闭writer
        out.close();
    }

}