关于JSP中基于Session的在线用户统计分析

public void logout() 

throws SQLException,ACLException 

{ 

　if (this.user == null && this.session.getAttribute("user")==null) 

　{ 

return; 

　} 


　Vector activeSessions = (Vector) this.application.getAttribute("activeSessions"); 

　if (activeSessions != null) 

　{ 

activeSessions.remove(this.session); 

application.setAttribute("activeSessions",activeSessions); 

　} 


　java.util.Enumeration e = this.session.getAttributeNames(); 


　while (e.hasMoreElements()) 

　{ 

String s = (String)e.nextElement(); 

this.session.removeAttribute(s); 

　} 

　this.user.touchLogoutTime(); 

　this.user = null; 

}

＜% 

HttpSessionManager hsm = new HttpSessionManager(application,request,response); 

try 

{ 

　hsm.login(); 

} 

catch ( UserNotFoundException e) 

{ 

　response.sendRedirect("InsufficientPrivilege.jsp?detail=User%20does%20not%20exist."); 

　return; 

} 

catch ( InvalidPasswordException e2) 

{ 

　response.sendRedirect("InsufficientPrivilege.jsp?detail=Invalid%20Password"); 

　return; 

} 

catch ( Exception e3) 

{ 

　%＞ Error:＜%=e3.toString() %＞＜br＞ 

　Press ＜a href="login.jsp"＞Here＜/a＞ to relogin. 

　＜% return; 

} 

response.sendRedirect("index.jsp"); 

%＞

＜body bgcolor="#FFFFFF"＞ 

＜table cellspacing="0" cellpadding="0" width="100%"＞ 


＜tr ＞ 

＜td style="width:24px"＞SessionId 

＜/td＞ 

＜td style="width:80px" ＞User 

＜/td＞ 

＜td style="width:80px" ＞Login Time 

＜/td＞ 

＜td style="width:80px" ＞Last Access Time 

＜/td＞ 

＜/tr＞ 

＜% 

Vector activeSessions = (Vector) application.getAttribute("activeSessions"); 

if (activeSessions == null) 

{ 

　activeSessions = new Vector(); 

　application.setAttribute("activeSessions",activeSessions); 

} 


Iterator it = activeSessions.iterator(); 

while (it.hasNext()) 

{ 

　HttpSession sess = (HttpSession)it.next(); 

　JDBCUser sessionUser = (JDBCUser)sess.getAttribute("user"); 

　String userId = (sessionUser!=null)?sessionUser.getUserID():"None"; 

%＞ 

＜tr＞ 

＜td nowrap=''＞＜%= sess.getId() %＞＜/td＞ 

＜td nowrap=''＞＜%= userId %＞＜/td＞ 

＜td nowrap=''＞ 

＜%= BeaconDate.getInstance( new Java.util.Date(sess.getCreationTime())).
getDateTimeString()%＞＜/td＞ 

＜td class="＜%= stl %＞3" nowrap=''＞ 

＜%= BeaconDate.getInstance( new java.util.Date(sess.getLastAccessedTime())).
getDateTimeString()%＞＜/td＞ 

＜/tr＞ 

＜% 

} 

%＞ 

＜/table＞ 

＜/body＞