java webÖÐʹÓà Listener
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# ServletContextAttributeListener¼àÌý¶ÔServletContextÊôÐԵIJÙ×÷£¬±ÈÈçÔö¼Ó¡¢É¾³ý¡¢ÐÞ¸ÄÊôÐÔ¡£
# ServletContextListener¼àÌýServletContext¡£µ±´´½¨ServletContextʱ£¬¼¤·¢ contextInitialized(ServletContextEvent sce)·½·¨£»µ±Ïú»ÙServletContextʱ£¬¼¤·¢contextDestroyed(ServletContextEvent sce)·½·¨¡£
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# HttpSessionAttributeListener¼àÌýHttpSessionÖеÄÊôÐԵIJÙ×÷¡£µ±ÔÚSessionÔö¼ÓÒ»¸öÊôÐÔʱ£¬¼¤·¢ attributeAdded(HttpSessionBindingEvent se) ·½·¨£»µ±ÔÚSessionɾ³ýÒ»¸öÊôÐÔʱ£¬¼¤·¢attributeRemoved(HttpSessionBindingEvent se)·½·¨£»µ±ÔÚSessionÊôÐÔ±»ÖØÐÂÉèÖÃʱ£¬¼¤·¢attributeReplaced(HttpSessionBindingEvent se) ·½·¨¡£
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# HttpSessionListener
# ServletContextListener
# ServletContextAttributeListener
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1 // ==================== Program Discription =====================
2 // ³ÌÐòÃû³Æ£ºÊ¾Àý14-9 : EncodingFilter .java
3 // ³ÌÐòÄ¿µÄ£ºÑ§Ï°Ê¹ÓüàÌýÆ÷
4 // ==============================================================
5 import javax.servlet.http.*;
6 import javax.servlet.*;
7
8 public class OnLineCountListener implements HttpSessionListener,
ServletContextListener,ServletContextAttributeListener
9 {
10 private int count;
11 private ServletContext context = null;
12
13 public OnLineCountListener()
14 {
15 count=0;
16 //setContext();
17 }
18 //
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