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How to define order of ServletContextListener's execution due application initialization, if i have multiple ServletContextListener's and some of them declared in deployment descriptor and other with annotation (@WebListener)?
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Receives notification that the web application initialization process is starting. All ServletContextListeners are notified of context initialization before any filters or servlets in the web application are initialized.
Servlet Listener is used for listening to events in a web container, such as when you create a session or place an attribute in a session or if you passivate and activate in another container, to subscribe to these events you can configure listener in web. xml, for example, HttpSessionListener.
A context listener receives notifications when the web application (ie: the context) is starting up or shutting down.
If you want to execute listeners in a particular order, you should use deployment descriptor to define them.
Below statements are copied from Servlet Specification:
8.2.3:
If the order in which the listeners, servlets, filters are invoked is important to an application then a deployment descriptor must be used. When using annotations to define the listeners, servlets and filters, the order in which they are invoked is unspecified.
The ordering will be based on the order in which they are defined in the descriptor and on the absolute-ordering element in the
web.xmlor an ordering element in theweb-fragment.xml.Prior to this release of the specification (Java™ Servlet Specification, version 3), context listeners were invoked in random order. As of Servlet 3.0, the listeners are invoked in the order in which they are declared in the web.xml.
Implementations of
javax.servlet.ServletContextListenerare invoked at theircontextInitializedmethod in the order in which they have been declared, and at theircontextDestroyedmethod in reverse order.
If you have multiple ServletContextListeners and some of them are declared in deployment descriptor and others with annotation, then its the listeners defined in web.xml that will get the precedence. Below statement is copied from the same section (8.2.3) of servlet specification:
Configuration specified in the main web.xml or a web fragment takes precedence over the configuration specified via annotations.
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It seems you know the order of execution but you want to know what will it be if some listeners are declared in deployment descriptor and some using annotation so the preference is taken by deployment descriptor and then annotation.
Note the constructors of all listeners will be called first in order of deployment descriptor & then annotation and then the life cycle methods in same order.
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