野心家

导航

用servlet实现用户登录案例

以下实现登录窗口 Login.jsp

<!--Login.jsp-->
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>

<html>
  <head>    <title>登录页面</title>  </head>
  
  <body bgcolor="cccfff">

   <form action="Check" method="post">
   <table>
  		<tr><td>用户</td><td><input type="text"name="user"></td></tr>
  		<tr><td>密码</td><td><input type="password"name="password"></td></tr>
  		<tr align="center">
  			<td colspan="2">
  				  <input type="submit"value="登 录">
  				   
  				<input type="reset"value="取 消 ">
  			</td>
  		</tr>
  	</table>
   </form>
  </body>
</html>

　　

 

处理登录的Servlet

package ch04;

import java.io.IOException;

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

public class Check extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
	public Check() {
		super();
	}

	/**
	 * Destruction of the servlet. <br>
	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	/**
	 * The doGet method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	/*
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		response.setContentType("text/html");
		PrintWriter out = response.getWriter();
		out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
		out.println("<HTML>");
		out.println("  <HEAD><TITLE>A Servlet</TITLE></HEAD>");
		out.println("  <BODY>");
		out.print("    This is ");
		out.print(this.getClass());
		out.println(", using the GET method");
		out.println("  </BODY>");
		out.println("</HTML>");
		out.flush();
		out.close();
	}
	*/

	/**
	 * The doPost method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to post.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		   String name=request.getParameter("user");//获取用户名
		   String password=request.getParameter("password");//获取密码
		   
		 
		   if(("client".equals(name))&&"123456".equals(password)){//设置用户名和密码
			   //如果用户名和密码相对应，则跳转到学生体质管理页面
			   RequestDispatcher rd=request.getRequestDispatcher("success.jsp");
					   rd.forward(request, response);
			   
		   }else{//账户名或密码不正确则跳转登录失败页面
			   
			   RequestDispatcher rd=request.getRequestDispatcher("Faile.jsp");
			   rd.forward(request, response);
		   }
		 
	}

	/**
	 * Initialization of the servlet. <br>
	 *
	 * @throws ServletException if an error occurs
	 */
	public void init() throws ServletException {
		// Put your code here
	}

}

 

登录成功页面success.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>

<html>
  <head>    <title>成功页面</title>  </head>
  
  <body>
   <%String Name=request.getParameter("user"); %>
   欢迎，<%=Name %>成功登陆！
  </body>
</html>

　　

 

登录失败页面Faile.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>

<html>
  <head>    <title>失败页面</title>  </head>
  
  <body>
   登陆失败！
   <!--获取用户名  -->
    <%String Name=request.getParameter("user"); %>
    <!--重新跳转到登陆页面  -->
   <br><a href="Login.jsp">请重新登录，<%=Name %>同学！   
  </body>
</html>

　　

配置文件，在web.xml中，添加Check的配置信息，

（注意jsp页面调用Servlet的方法）

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
  <servlet>
    
    <servlet-name>Check</servlet-name>
    <servlet-class>ch04.Check</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>Check</servlet-name>
    <url-pattern>/Check</url-pattern>
  </servlet-mapping>

</web-app>

　　

 

posted on 2017-12-04 19:15  野心家  阅读(4978)  评论(0)    收藏  举报