关于JSP中基于Session的在线用户统计分析[2]

假设其中的JDBCUser类是一个任意User类在执行用户登录时把User类和HttpSessionBinding类都加入到Session中去

这样每次用户登录后在application中的attribute activeSessions这个vector中都会增加一条记录每当session超时valueUnbound被触发在这个vector中删去将要被超时的session

public void login()

throws ACLExceptionSQLExceptionIOException

{

/* get JDBC User Class */

if (user != null)

{

logout();

}

{

// if session time out or user didnt login save the target url temporary

JDBCUserFactory uf = new JDBCUserFactory();

if ( (thisrequestgetParameter(userID)==null) || (thisrequestgetParameter(password)==null) )

{

  throw new ACLException(Please input a valid userName and password);

}

JDBCUser user = (JDBCUser) ufUserLogin(

thisrequestgetParameter(userID)

thisrequestgetParameter(password) );

usertouchLoginTime();

thissessionsetAttribute(useruser);

thissessionsetAttribute(BindingNotifynew HttpSessionBinding(application));

}

}

Login的时候把User和这个BindingNotofy目的的类都加入到session中去logout的时候就要主动在activeSessions这个vector中删去这个session

public void logout()

throws SQLExceptionACLException

{

if (thisuser == null && thissessiongetAttribute(user)==null)

{

return;

}

Vector activeSessions = (Vector) thisapplicationgetAttribute(activeSessions);

if (activeSessions != null)

{

activeSessionsremove(thissession);

applicationsetAttribute(activeSessionsactiveSessions);

}

javautilEnumeration e = thissessiongetAttributeNames();

while (ehasMoreElements())

{

String s = (String)enextElement();

thissessionremoveAttribute(s);

}

thisusertouchLogoutTime();

thisuser = null;

}

这两个函数位于一个HttpSessionManager类中这个类引用了jsp里面的application全局对象这个类的其他代码和本文无关且相当长我就不贴出来了

下面来看看JSP里面怎么用

假设一个登录用的表单被提交到doLoginjsp 表单中包含UserName和password域节选部分片段

＜%

HttpSessionManager hsm = new HttpSessionManager(applicationrequestresponse);

try

{

hsmlogin();

}

catch ( UserNotFoundException e)

{

responsesendRedirect(InsufficientPrivilegejsp?detail=User%does%not%exist);

return;

}

catch ( InvalidPasswordException e)

{

responsesendRedirect(InsufficientPrivilegejsp?detail=Invalid%Password);

return;

}

catch ( Exception e)

{

%＞ Error:＜%=etoString() %＞＜br＞

Press ＜a href=loginjsp＞Here＜/a＞ to relogin

＜% return;

}

responsesendRedirect(indexjsp);

%＞

[] [] []