servlet01 项目demo

1 环境说明

　　jdk: 1.8

　　tomcat: 8.0

2 项目demo

　　2.1 新建一个动态的web项目

　　2.2 新建一个servlet类

　　　　该类必须继承 HttpServlet

　　　　技巧01：HttpServlet 继承自 Servlet

　　　　技巧02：@WebServlet("/ServletDemo01") 的作用是设置访问路径，当然也可以在web.xml文件中进行设置；web.xml中的设置方式如下（本实例利用的是前者）

    <servlet>  
        <!-- 当前servlet的名称 -->  
        <servlet-name>HelloServlet</servlet-name>  
        <!-- servlet所在的包名跟类名 -->  
        <servlet-class>servlet_demo.controller.ServletDemo01</servlet-class>  
    </servlet>  
    <servlet-mapping>  
        <!-- 必须于上一个servlet标签中的名称保持一致 -->  
        <servlet-name>HelloServlet</servlet-name>  
        <!-- 这是你在浏览器上访问的地址,必须要提 /servlet/xxxx 格式，不然tomcat启动会报错-->  
        <url-pattern>/servlet/helloWorld</url-pattern>  
    </servlet-mapping>

package servlet_demo.controller;

import java.io.IOException;
import java.io.PrintWriter;

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

/**
 * Servlet implementation class ServletDemo01
 */
@WebServlet("/ServletDemo01")
public class ServletDemo01 extends HttpServlet {
    private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public ServletDemo01() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // TODO Auto-generated method stub
        PrintWriter out = resp.getWriter();  
        out.println("hello world,servlet");  
        out.close();  
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
    }

}