JSP 中Servlet的自己实现
一 步骤
1、继承HttpServlet
2、重写doGet()或者doPost()方法
3、在web.xml中注册Servlet
二 HttpServlet类继承图
三 实例
1、创建MyFirstServletDemo web project.
2、编辑index.jsp
<%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>" rel="external nofollow" >
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css" rel="external nofollow" >
-->
</head>
<body>
<h1>第一个Servlet小例子</h1>
<a href="servlet/HelloServlet" rel="external nofollow" >Get方式请求HelloServlet</a>
<form action="servlet/HelloServlet" method="post">
<input type="submit" value="Post方式请求HelloServlet">
</form>
</body>
</html> 3、编写HelloServlet
package servlet;
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;
//继承于HttpServlet
public class HelloServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// TODO Auto-generated method stub
System.out.println("处理get()请求...");
PrintWriter out = response.getWriter();
response.setContentType("text/html; charset=utf-8");
out.println("<strong>Hello Servlet!</strong><br>");
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("处理post()请求...");
PrintWriter out = response.getWriter();
response.setContentType("text/html; charset=utf-8");
out.println("<strong>Hello Servlet!</strong><br>");
}
} 4、编写web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="https://java.sun.com/xml/ns/javaee";
xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance";
xsi:schemaLocation="https://java.sun.com/xml/ns/javaee
https://java.sun.com/xml/ns/javaee/web-app_2_5.xsd";>
<display-name></display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>HelloServlet</servlet-name>
<servlet-class>servlet.HelloServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>HelloServlet</servlet-name>
<url-pattern>/servlet/HelloServlet</url-pattern>
</servlet-mapping>
</web-app> 四 运行结果
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