jsp很有用的功能listeners,出现了很奇怪的问题,要不你亲自试一下!!!
Tomcat 4.0版本
web.xml:
<listener>
<listener-class>listeners.ContextListener</listener-class>
</listener>
ContextListener.java:
package listeners;
import javax.servlet.ServletContext;
import javax.servlet.ServletContextAttributeEvent;
import javax.servlet.ServletContextAttributeListener;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
public final class ContextListener
implements ServletContextAttributeListener, ServletContextListener {
.................
public void contextInitialized(ServletContextEvent event) {
System.out.println("222222");
}
}
结果输出了22222222两遍,也就是说contextInitialized执行乐次,为什么???