Springboot's event Release system

For springboot applications, starting a spring container is roughly the following process:

• The container starts to start
• Initializing environment variables
• Initializing context
• Load context
• Complete

The listener of the corresponding spring application's initiator can listen to the above procedure, the interface is as follows:

1  Public InterfaceSpringapplicationrunlistener {2 3     /**4 * Called immediately when the Run method has first started. Can is used for very5 * Early initialization.6      */7     voidstarted ();8 9     /**Ten * Called once the environment have been prepared, but before the One      * {@linkApplicationContext} has been created. A      * @paramEnvironment The Environment -      */ -     voidenvironmentprepared (configurableenvironment environment); the  -     /** - * Called once the {@linkApplicationContext} had been created and prepared, but - * Before sources has been loaded. +      * @paramcontext the application context -      */ +     voidcontextprepared (Configurableapplicationcontext context); A  at     /** - * Called once the application context had been loaded but before it had been - * refreshed. -      * @paramcontext the application context -      */ -     voidcontextloaded (Configurableapplicationcontext context); in  -     /** to * called immediately before the Run method finishes. +      * @paramcontext the application context or NULL if a failure occurred before the - * Context was created the      * @paramexception any run exception or null if run completed successfully. *      */ $     voidfinished (configurableapplicationcontext context, throwable exception);Panax Notoginseng  -}

Listener

Corresponding to several key events

Each method in the listener interface represents a stage in the container initiation process, and each stage can be customized to perform a series of tasks. Springapplicationrunlistener can be understood as a command pattern (passing in an object, as to the current point in time, how to call, not caring). Springapplicationrunlistener has a special implementation of Eventpublishingrunlistener, his main function is to start a special event at a specific point in time.

@Override Public voidstarted () { This. Initialmulticaster.multicastevent (NewApplicationstartedevent ( This. Application, This. args)); } @Override Public voidenvironmentprepared (configurableenvironment environment) { This. Initialmulticaster.multicastevent (NewApplicationenvironmentpreparedevent ( This. Application, This. args, environment)); }

Springapplicationrunlisteners is a proxy for multiple springapplicationrunlistener, aggregating multiple springapplicationrunlistener, completing in either process, The corresponding method is called in turn.

    Private FinalList<springapplicationrunlistener>listeners; Springapplicationrunlisteners (log log, Collection<?extendsSpringapplicationrunlistener>listeners) {         This. log =log;  This. Listeners =NewArraylist<springapplicationrunlistener>(listeners); }     Public voidstarted () { for(Springapplicationrunlistener Listener: This. Listeners)        {listener.started (); }    }     Public voidenvironmentprepared (configurableenvironment environment) { for(Springapplicationrunlistener Listener: This. Listeners)        {listener.environmentprepared (Environment); }    }

Event release with Observer pattern

Springboot's event Release system