演示Session Listener的使用方法

import Java.util.Date;

import javax.servlet.http.HttpSession;

import javax.servlet.http.HttpSessionEvent;

import javax.servlet.http.HttpSessionListener;

public class SessionListen implements HttpSessionListener {

private int sessionCount;

public SessionListen() {

this.sessionCount = 0;

}

public void sessionCreated(HttpSessionEvent se) {

HttpSession session = se.getSession();

session.setMaxInactiveInterval(60);

synchronized (this) {

sessionCount++;

}

String id = session.getId();

Date now = new Date();

String message = new StringBuffer("New Session created on ").append(

now.toString()).append("\nID: ").append(id).append("\n")

.append("There are now ").append("" + sessionCount).append(

" live sessions in the application.").toString();

System.out.println(message);

}

public void sessionDestroyed(HttpSessionEvent se) {

HttpSession session = se.getSession();

String id = session.getId();

synchronized (this) {

--sessionCount;

}

String message = new StringBuffer("Session destroyed"

+ "\nValue of destroyed session ID is").append("" + id).append(

"\n").append("There are now ").append("" + sessionCount)

.append(" live sessions in the application.").toString();

System.out.println(message);

}

}

（出处：http://www.knowsky.com）