監聽器[用於監聽ServletRequest對象的產生和銷燬] 學習筆記

import javax.servlet.ServletRequestEvent;
import javax.servlet.ServletRequestListener;

//監聽器[用於監聽ServletRequest對象的產生和銷燬]
public class MyServletRequestListener implements ServletRequestListener {
    //產生
    public void requestInitialized(ServletRequestEvent sre) {
        System.out.println("requestInitialized()");
    }
    //銷燬
    public void requestDestroyed(ServletRequestEvent sre) {
        System.out.println("requestDestroyed()");
    }
}

<listener>
<listener-class>cn.itcast.web.listener.MyServletRequestListener</listener-class>
</listener>

    >>創建和銷燬：ServletContextListener，Web容器部署時產生，Web容器重新部署時銷燬原ServletContext對象
            >>屬性變化：ServletContextAttributeListner
        application.setAttirbute("name","jack")
        setAttribute("name","liw")
        removeAttribute("name")