纯JSP简单登录实例

记一下，免得以后忘记了，又要去查。

文件共有四个web.xml、login.jsp、logout.jsp、welcome.jsp四个文件

测试环境：Tomcat 6.0.x

假设项目名称是LoginSample，我的目录结构是这样的

...\webapps\LoginSample\WEB-INF\web.xml

...\webapps\LoginSample\login.jsp

...\webapps\LoginSample\logout.jsp

...\webapps\LoginSample\welcome.jsp

----------------------------------------------------------------------------------------------

web.xml源码清单

	
		welcome.jsp
	

login.jsp源码清单

<%@ page contentType="text/html;charset=UTF-8" %>

 
   
 
 
 
  
请登录

  

   Login Name: 

   Login Password: 

   

  

  <%
	  if (request.getParameter("Name") != null 
			  && request.getParameter("Password") != null) {  
		  String Name = request.getParameter("Name");
		  String Password = request.getParameter("Password");
		  if (Name.equals("a") && Password.equals("a")) {   
			  session.setAttribute("Login", "OK");
			  session.setAttribute("myCount", new Integer(1));
			  response.sendRedirect("welcome.jsp");
		  }
		  else {   
			  %>
			  登录失败:用户名或密码不正确～
			  <%  
		  } 
	  }
%>
 

logout.jsp源码清单

<%@ page contentType="text/html;charset=UTF-8" %>

 
 <%
	session.setAttribute("Login", "");
 %>

 
  
你已经退出登录
 

welcome.jsp源码清单

<%@ page contentType="text/html" pageEncoding="UTF-8" import="java.util.*"%>

 
 
  
欢迎页面(测试session)
  
  <%
  
  String  Login = (String)session.getAttribute("Login");
  int     nCount=0;


  if (Login != null && Login.equals("OK")) {
	  Integer myCount = (Integer)session.getAttribute("myCount");
	  if(myCount!=null)
	  {
		  nCount = myCount.intValue();  
		  nCount = nCount + 1;
		  session.setAttribute("myCount",new Integer(nCount));
	  }
	  %>
	  登录成功,myCount=<%=nCount%>

	  
	  <%
  }
  else {
%>
     
<%
   }
   %>