Tomcat 8.x "Application", Listener (life cycle monitor, Event listener)

The following listening can be configured in the Web-inf/web.xml file

	<listener>
	    <listener-class>cn.java.listener.event.myhttpsessionattributelistener</ Listener-class>
	</listener>

Listener Interface List

		Event listener
//		Javax.servlet.ServletContextAttributeListener;		Javax.servlet.ServletRequestAttributeListener;		Javax.servlet.HttpSessionAttributeListener;		Javax.servlet.ServletRequestListener;		Javax.servlet.HttpSessionIdListener;
		
		Life cycle listener
//		 Javax.servlet.ServletContextListener;		 Javax.servlet.http.HttpSessionListener;

Event listeners

Session Property modification, event listener

Package cn.java.listener.event;
Import Javax.servlet.http.HttpSessionAttributeListener;

Import javax.servlet.http.HttpSessionBindingEvent; The public class Myhttpsessionattributelistener implements Httpsessionattributelistener {/** * triggers when adding attributes * Trigger location: Request
	 . GetSession (). setattribute ("Key1", "value1");  * * @Override public void attributeadded (Httpsessionbindingevent event) {//Event.getsource () = = event.getsession () = = 
	 Org.apache.catalina.session.StandardSessionFacade//Event.getname () = "Key1"//event.getvalue () = = "Value1"}/** * Trigger location When deleting attributes: Request.getsession (). RemoveAttribute ("Key1")/@Override public void attributeremoved (httpses Sionbindingevent event) {//Event.getsource () = = event.getsession () = = = Org.apache.catalina.session.StandardSessionFacade//Event.getname () = "Key1"//event.getvalue () = "Old Value"}/** *
	 When the property is replaced or modified, the trigger location is triggered: Request.getsession (). setattribute ("Key1", "value1_new"); */@Override public void attributereplaced (HTTPsessionbindingevent event) {//Event.getsource () = = event.getsession () = = =
 Org.apache.catalina.session.StandardSessionFacade//event.getname () = = "Key1"//event.getvalue () = = "Old Value"}}

SessionID when modified, event listener

Package cn.java.listener.event;

Import javax.servlet.http.HttpSessionEvent;
Import Javax.servlet.http.HttpSessionIdListener;

The public class Myhttpsessionidlistener implements Httpsessionidlistener {

	/**
	 * Changes the SessionID when the trigger
	 * Org.apache.catalina.session.StandardSession.tellChangedSessionId (...);
	 * Trigger Location: Request.changesessionid ();
	 */
	@Override public
	void Sessionidchanged (Httpsessionevent event, String Oldsessionid) {
//		Event.getsession () = = = Event.getsource () = = =  org.apache.catalina.session.StandardSessionFacade
	}

}

ServletContext Context Property modification, event listener

Package cn.java.listener.event;
Import javax.servlet.ServletContextAttributeEvent;

Import Javax.servlet.ServletContextAttributeListener; The public class Myservletcontextattributelistener implements Servletcontextattributelistener {/** * triggers the trigger location when adding properties
	 : Request.getservletcontext (). setattribute ("Key1", "value1"); */@Override public void attributeadded (Servletcontextattributeevent event) {//event.getservletcontext () = = Event.get Source () = = Org.apache.catalina.core.ApplicationContextFacade//event.getname () = "Key1"//event.getvalue () = "Val" Ue1 "}/** * Trigger location: Request.getservletcontext () removeattribute (" Key1 ")/@Override public void at Tributeremoved (Servletcontextattributeevent event) {//event.getservletcontext () = = Event.getsource () = =
	 Org.apache.catalina.core.ApplicationContextFacade//event.getname () = = "Key1"//event.getvalue () = "Old Value"}/** * Trigger location when replacing and modifying attributes: Request.getservletcontext () setattribute ("Key1", "Value1_nEW "); */@Override public void attributereplaced (Servletcontextattributeevent event) {//event.getservletcontext () = = Event GetSource () = = Org.apache.catalina.core.ApplicationContextFacade//event.getname () = = "Key1"//event.getvalue () = =
 "Old Value"}}

Request property modification, Event listener

Package cn.java.listener.event;
Import javax.servlet.ServletRequestAttributeEvent;

Import Javax.servlet.ServletRequestAttributeListener; The public class Myservletrequestattributelistener implements Servletrequestattributelistener {/** * triggers the trigger location when adding properties: R
	 Equest.setattribute ("Key1", "value1"); */@Override public void attributeadded (Servletrequestattributeevent event) {//event.getservletcontext () = = Event.get Source () = = Org.apache.catalina.core.ApplicationContextFacade//event.getname () = "Key1"//event.getvalue () = "Value" 1 "//event.getservletrequest () = = Org.apache.catalina.connector.RequestFacade = = Request}/** * trigger when deleting attribute		Point: Request.removeattribute ("Key1") */@Override public void attributeremoved (Servletrequestattributeevent event) {// Event.getservletcontext () = = Event.getsource () = = Org.apache.catalina.core.ApplicationContextFacade//Event.getname () = = "Key1"//event.getvalue () = "Old value"//event.getservletrequest () = = Org.apache.catalina. Connector.
	 Requestfacade = = Request}/** * Trigger location: Request.setattribute ("Key1", "value1_new") when replacing and modifying attributes * * @Override public void attributereplaced (Servletrequestattributeevent event) {//event.getservletcontext () = = event. GetSource () = = Org.apache.catalina.core.ApplicationContextFacade//event.getname () = "Key1"//event.getvalue () = "Old value"
 "//event.getservletrequest () = = Org.apache.catalina.connector.RequestFacade = = Request}}

Request creation, destruction, event listeners

Package cn.java.listener.event;

Import javax.servlet.ServletRequestEvent;
Import Javax.servlet.ServletRequestListener;

public class Myservletrequestlistener implements Servletrequestlistener {

	/**
	 * Request Destruction
	 * Trigger Location: Org.apache.catalina.core.StandardHostValve.invoke (Request request, Response Response)
	 * * *
	@Override Public
	void Requestdestroyed (Servletrequestevent event) {
//		event.getservletcontext () = = Event.getsource () = = Org.apache.catalina.core.ApplicationContextFacade  
//		event.getservletrequest () = = Org.apache.catalina.connector.Request
		
	}

	/**
	 * Request Initialization
	 * Trigger Location: Org.apache.catalina.core.StandardHostValve.invoke (Request request, Response Response)
	 * * *
	@Override Public
	void Requestinitialized (Servletrequestevent event) {
//		event.getservletcontext () = = Event.getsource () = = Org.apache.catalina.core.ApplicationContextFacade  
//		event.getservletrequest () = = Org.apache.catalina.connector.Request
	}

}

Life cycle Listeners

Session creation, destruction, lifecycle listeners

Package cn.java.listener.lifecycle;

Import javax.servlet.http.HttpSessionEvent;
Import Javax.servlet.http.HttpSessionListener;

/** * Session Lifecycle
 * @author Administrator * * */Public
class Myhttpsessionlistener implements Httpsessionlistener {


	/**
	 * Trigger Location 1:
	 * 		Request.changesessionid ();
	 * 		org.apache.catalina.session.StandardSession.setId (String ID)
	 * 		Org.apache.catalina.session.StandardSession.tellNew ()
	 */
	@Override public
	void sessioncreated ( Httpsessionevent event) {
//		event.getsource () = = Event.getsource () = =  Org.apache.catalina.session.StandardSessionFacade
	}

	/**
	 * Trigger Location: Org.apache.catalina.session.StandardSession.expire (Boolean notify)
	 */
	@Override public
	Void Sessiondestroyed (Httpsessionevent event) {
//		event.getsource () = = Event.getsource () = =  Org.apache.catalina.session.StandardSessionFacade
	}

}

ServletContext context creation, destruction, declaring periodic listeners

Package cn.java.listener.lifecycle;

Import javax.servlet.ServletContextEvent;

/** *
 server startup, Shutdown
 * * 
 start context, or destroy context when triggering
 * @author Administrator */Public
class Myservletcontextlistener implements Javax.servlet.ServletContextListener {

	/**
	 * Trigger location: org.apache.catalina.core.StandardContext.startInternal ()
	 */
	@Override public
	Void Contextinitialized (Servletcontextevent event) {
//		event.getsource () = = Event.getservletcontext () = = Org.apache.catalina.core.ApplicationContextFacade  
	}
	
	/**
	 * Trigger location: org.apache.catalina.core.StandardContext.stopInternal ()
	 */
	@Override public
	Void Contextdestroyed (Servletcontextevent event) {
//		event.getsource () = = Event.getservletcontext () = = Org.apache.catalina.core.ApplicationContextFacade  

	}

}