counterlistener.java

用java编写的程序

package webbook.chapter14;

import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;

public class CounterListener implements HttpSessionListener {
	private static long onlineNumber = 0;

	public static long getOnlineNumber() {
		return onlineNumber;
	}

	public void sessionCreated(HttpSessionEvent se) {
		onlineNumber++;
	}

	public void sessionDestroyed(HttpSessionEvent se) {
		onlineNumber--;
	}
}