Servlet 第一课：简单Servlet Demo，写一个Hello Servlet

今天和大家一起写一个简单的Hello Servlet。

目录结构如下：

展示效果：

详细步骤：

01.新建WebProject：

02.创建MyServlet.java.(这里面要特别注意

super.doGet(req, resp)
<pre name="code" class="java">super.doPost(req, resp);

//上面两句必须注释，不能调用，否者会出错。

)

package com.goxuexi.demo;

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

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

public class MyServlet extends HttpServlet{
	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		// TODO Auto-generated method stub
		//super.doGet(req, resp);
		
		//logic
		//HttpServletRequest 请求类
		//HttpServletResponse 响应类
		
		PrintWriter out = resp.getWriter();
		out.print("Hello Servlet");
		out.close();
		
		
		
	}
	
	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		// TODO Auto-generated method stub
		//super.doPost(req, resp);
		doGet(req, resp);
	}

}

03.在Web.xml中添加Servlet的注册。

  <servlet>
  <servlet-name>MyServlet</servlet-name>
  <servlet-class>com.goxuexi.demo.MyServlet</servlet-class>
  
  
  </servlet>
  <servlet-mapping>
  <servlet-name>MyServlet</servlet-name>
  <url-pattern>/hello.html</url-pattern>
  </servlet-mapping>

上面注意两点：

①：servlet-name必须一样。

②url-pattern中必须以/开头，且后面是什么不会做限制。

③：网络访问地址为：http://localhost:8080/ServletDemo/hello.html