Unit01: Servlet基础 、 HTTP协议

时间:2024-03-22 19:03:20

    Unit01: Servlet基础 、 HTTP协议    

在页面上输出当前时间

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();
} }

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
<display-name>servlet1</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list> <!-- 1.给Servlet取一个别名 -->
<servlet>
<servlet-name>time</servlet-name>
<servlet-class>web.TimeServlet</servlet-class>
</servlet>
<!-- 2.给Servlet取一个网络访问路径(网名) -->
<servlet-mapping>
<servlet-name>time</servlet-name>
<url-pattern>/ts</url-pattern>
</servlet-mapping> </web-app>

web.xml