Servlet Hello World程序

下文是笔者编写的Servlet Hello World程序，供大家学习，如下所示:

实现思路:
    1.建立相应的Class文件
   
    2.配置相应的web.xml文件
  
    3.启动tomcat测试Servlet

Servlet需实现一个Servlet接口，下例中实现的是一个HttpServlet类，并重写其中的doGet方法，如下所示:

package servlet01;

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 ServletHelloWorld extends HttpServlet {

	/**
	 * 
	 */
	private static final long serialVersionUID = 888;

	private String msg;

	@Override
	public void init() throws ServletException {
		// TODO Auto-generated method stub
		super.init();
		msg = "java265.com is Java WebSite.";
	}

	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		// TODO Auto-generated method stub
		resp.setContentType("text/html");

		// 实际的逻辑是在这里
		PrintWriter o = resp.getWriter();
		o.println("<h1>" + msg + "</h1>");

	}

}

二、配置相应的web.xml

 
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>servlet01</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>
  
  
 <servlet>
        <servlet-name>helloWorld</servlet-name>
        <servlet-class>servlet01.ServletHelloWorld</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>helloWorld</servlet-name>
        <url-pattern>/index</url-pattern>
    </servlet-mapping>
  
</web-app>

三、使用tomcat运行此示例程序，将会得到以下效果

源码下载