/**
* 此类实现ServletRequestListener接口是关键，因为此接口中的方法可以实现对request的监听，这样我们就可以从参数ServletRequestEvent中获取request了
* @author vivi
*
*/
public class OlineListener implements HttpSessionListener,HttpSessionAttributeListener,ServletContextListener,ServletRequestListener{
//用Map来存储session，sessionid作为key session作为value
private static Map sessionMap = new HashMap<String,HttpSession>();
HttpServletRequest request;
public void sessionCreated(HttpSessionEvent se) {
//当session 创建的时候，例如我要监听统计在线人数 并且获取当前session的ip
HttpSession session = se.getSession();
String ip = request.getRemoteAddr();//获取客户端ip
session.setAttribute("ip", ip);
String sid = session.getId();//获取sessionId
sessionMap.put(sid, session);
}
public static int getOline(){
return sessionMap.size();//获取在线人数，获取到session 就可以拿到ip了
}
public void requestDestroyed(ServletRequestEvent arg0) {
}
public void requestInitialized(ServletRequestEvent sre) {
request = (HttpServletRequest)sre.getServletRequest();//获取request
}
public void sessionDestroyed(HttpSessionEvent arg0) {
// 销毁session或者session超时时
}
public void attributeAdded(HttpSessionBindingEvent arg0) {
//这里是监听当session调用setAtrribute()方法时，例如用户登录，将用户信息设置进session
}
public void attributeRemoved(HttpSessionBindingEvent arg0) {
//这里监听当session调用removeAttribute()方法时
}
public void attributeReplaced(HttpSessionBindingEvent arg0) {
}
public void contextDestroyed(ServletContextEvent arg0) {
}
public void contextInitialized(ServletContextEvent arg0) {
}
}