单用户单账户登录

第一步：搭架子，把 SSH 整合起来。参照：

http://sites.google.com/site/topcss/struts-spring-hibernate-de-ji-cheng


第二步：编写代码

1 、编写在线用户类：

package net.jiakuan.books.common;


import java.util.HashMap ;

import java.util.Map ;


public class OnlineUserMap

{

public static Map<String , String > onlineuser = new HashMap<String , String >();


/**

* 得到在线用户

* @return

*/

public static Map<String , String > getOnlineuser()

{

return onlineuser;

}


/**

* 添加在线用户

* @param sessionId

* @param userName

* @return

*/

public void addOnlineUser(String userId, String sessionId)

{

onlineuser.put(userId, sessionId);

}


/**

* 得到sessionId

* @param userName

* @return

*/

public String getSessionId(String userName)

{

return onlineuser.get(userName);

}


/**

* 判断用户是否登录

* @param name

* @return

*/

public boolean isLogin(String userName)

{

return onlineuser.containsKey(userName);

}


/**

* 移除用户

* @param userName

*/

public void removeUser(String userName)

{

onlineuser.remove(userName);

}

}



2 、系统参数类

package net.jiakuan.books.common;


public class SystemParameter

{

public static final String SESSION_USER_NAME = "loginUser" ; // SESSION 中的键名

}



3 、 Session 监听器

package net.jiakuan.books.webs.listener;


import javax.servlet.http.HttpSessionAttributeListener;

import javax.servlet.http.HttpSessionBindingEvent;


import net.jiakuan.books.common.OnlineUserMap;

import net.jiakuan.books.common.SystemParameter;


public class UserLoginListener implements HttpSessionAttributeListener

{


public void attributeAdded(HttpSessionBindingEvent evt)

{

String username = evt.getName();

String sessionId = evt.getSession().getId();


if (username == SystemParameter.SESSION_USER_NAME)

{

new OnlineUserMap().addOnlineUser(username, sessionId);

}

}


public void attributeRemoved(HttpSessionBindingEvent evt)

{

String username = evt.getName();

String sessionId = evt.getSession().getId();


if (username == SystemParameter.SESSION_USER_NAME)

{

OnlineUserMap online = new OnlineUserMap();

if (online.isLogin(username)

&& online.getSessionId(username).equals(sessionId))

{

online.removeUser(username);

}


}

}

}



4 、过滤器 [ 代码完全参照“伪代码”编写，所以没写注释。 ]

package net.jiakuan.books.webs.filters;


import java.io.IOException ;


import javax.servlet.Filter;

import javax.servlet.FilterChain;

import javax.servlet.FilterConfig;

import javax.servlet.ServletException;

import javax.servlet.ServletRequest;

import javax.servlet.ServletResponse;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;


import net.jiakuan.books.common.OnlineUserMap;

import net.jiakuan.books.common.SystemParameter;

import net.jiakuan.books.models.Users;


public class LoginFilter implements Filter

{

public void doFilter(ServletRequest arg0, ServletResponse arg1,

FilterChain chain) throws IOException , ServletException

{

HttpServletRequest request = (HttpServletRequest)arg0;

HttpServletResponse response = (HttpServletResponse)arg1;

String fn = request.getParameter("fn" );


if (fn != null && !"" .equals(fn) && !fn.equalsIgnoreCase("login" ))

{

HttpSession session = request.getSession();

Object obj = session.getAttribute(SystemParameter.SESSION_USER_NAME);


if (obj != null )

{

String username = ((Users)obj).getName();

OnlineUserMap online = new OnlineUserMap();


if (online.isLogin(username))

{

if (session.getId().equals(online.getSessionId(username)))

{

chain.doFilter(arg0, arg1);

}

else

{

response.getWriter().print("<script>window.location.href='common/login.jsp'</script>" );

}

}

else

{

response.getWriter().print("<script>window.location.href='common/login.jsp'</script>" );

}

}

else

{

response.getWriter().print("<script>window.location.href='common/login.jsp'</script>" );

}

}

else

{

chain.doFilter(arg0, arg1);

}


}

}



5 、 Action 里面的 2 个方法

package net.jiakuan.books.webs.actions;


import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;


import net.jiakuan.books.bll.face.IUsersBll;

import net.jiakuan.books.common.OnlineUserMap;

import net.jiakuan.books.common.SystemParameter;

import net.jiakuan.books.models.Users;

import net.jiakuan.books.webs.forms.UsersForm;


import org.apache.struts.action.ActionForm;

import org.apache.struts.action.ActionForward;

import org.apache.struts.action.ActionMapping;

import org.apache.struts.actions.DispatchAction;


public class UserAction extends DispatchAction

{


IUsersBll usersBll;


/***

* 登录

*/

public ActionForward login(ActionMapping mapping, ActionForm form,

HttpServletRequest request, HttpServletResponse response)

throws Exception

{

// 1. 得到用户输入

UsersForm usersform = (UsersForm)form;

// 2. new 用户并设值

Users users = new Users();

users.setLoginId(usersform.getUsers().getLoginId());

users.setLoginPwd(usersform.getUsers().getLoginPwd());

// 3. 调用业务逻辑层验证账户的有效性

Users result = this .usersBll.login(users);


if (result != null )

{

// 验证状态

if (result.getUserStates().getId() == 1)

{

request.getSession().setAttribute(SystemParameter.SESSION_USER_NAME, result);

// 把当前登录用户添加到在线用户Map 中

new OnlineUserMap().addOnlineUser(result.getName(), request.getSession().getId());


return mapping.findForward("user" );

}

else

{

return mapping.findForward("error" );

}

}

else

{

return mapping.findForward("error" );

}

}


/***

* 退出登录

*/

public ActionForward exit(ActionMapping mapping, ActionForm form,

HttpServletRequest request, HttpServletResponse response)

throws Exception

{

request.getSession().removeAttribute(SystemParameter.SESSION_USER_NAME);

return mapping.findForward("index" );

}


public void setUsersBll(IUsersBll usersBll)

{

this .usersBll = usersBll;

}

}