countlistener.java

来自「关于 Jaoso新闻文章发布系统 --- --- --- --- --- -」· Java 代码 · 共 59 行

package jaoso.count.web.listener;

import jaoso.count.service.CountService;

import jaoso.framework.service.ServiceLocator;

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


/**
 * @author 边缘孤客
 * 统计在线人数的监视器
 */
public class CountListener implements HttpSessionListener {

    //~ Static fields/initializers =============================================

    /**  在线人数 */
    private static int onlineCount = 0;

    //~ Instance fields ========================================================

    /**  统计服务 */
    private CountService countService = (CountService) ServiceLocator.getInstance()
                                                                     .getService("countService");

    //~ Methods ================================================================

    /**
     * (non-Javadoc)
     * @see javax.servlet.http.HttpSessionListener#sessionCreated(javax.servlet.http.HttpSessionEvent)
     */
    public final void sessionCreated(final HttpSessionEvent arg0) {

        countService.getCount(true);
        onlineCount++;
    }

    /**
     * (non-Javadoc)
     * @see javax.servlet.http.HttpSessionListener#sessionDestroyed(javax.servlet.http.HttpSessionEvent)
     */
    public final void sessionDestroyed(final HttpSessionEvent arg0) {

        if (onlineCount > 0) {
            onlineCount--;
        }
    }

    /**
     * @return Returns the onlineCount.
     */
    public static int getOnlineCount() {

        return onlineCount;
    }
}