org.springframework.context.event

## Class SimpleApplicationEventMulticaster

- java.lang.Object
- - org.springframework.context.event.AbstractApplicationEventMulticaster
  - - org.springframework.context.event.SimpleApplicationEventMulticaster

- All Implemented Interfaces:
    Aware, BeanFactoryAware, ApplicationEventMulticaster

      public class SimpleApplicationEventMulticaster
      extends AbstractApplicationEventMulticaster

  Simple implementation of the `ApplicationEventMulticaster` interface.

  Multicasts all events to all registered listeners, leaving it up to the listeners to ignore events that they are not interested in. Listeners will usually perform corresponding `instanceof` checks on the passed-in event object.

  By default, all listeners are invoked in the calling thread. This allows the danger of a rogue listener blocking the entire application, but adds minimal overhead. Specify an alternative TaskExecutor to have listeners executed in different threads, for example from a thread pool.

  Author:
    Rod Johnson, Juergen Hoeller
  See Also:
    `setTaskExecutor(java.util.concurrent.Executor)`

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `SimpleApplicationEventMulticaster()` Create a new SimpleApplicationEventMulticaster.
    `SimpleApplicationEventMulticaster(BeanFactory beanFactory)` Create a new SimpleApplicationEventMulticaster for the given BeanFactory.

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `protected Executor` | `getTaskExecutor()` Return the current TaskExecutor for this multicaster.
    `void` | `multicastEvent(ApplicationEvent event)` Multicast the given application event to appropriate listeners.
    `void` | `setTaskExecutor(Executor taskExecutor)` Set the TaskExecutor to execute application listeners with.

    - ### Methods inherited from class org.springframework.context.event.AbstractApplicationEventMulticaster

      `addApplicationListener, addApplicationListenerBean, getApplicationListeners, getApplicationListeners, removeAllListeners, removeApplicationListener, removeApplicationListenerBean, setBeanFactory, supportsEvent`

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### SimpleApplicationEventMulticaster

          public SimpleApplicationEventMulticaster()

      Create a new SimpleApplicationEventMulticaster.

    - #### SimpleApplicationEventMulticaster

          public SimpleApplicationEventMulticaster(BeanFactory beanFactory)

      Create a new SimpleApplicationEventMulticaster for the given BeanFactory.

  - ### Method Detail

    - #### setTaskExecutor

          public void setTaskExecutor(Executor taskExecutor)

      Set the TaskExecutor to execute application listeners with.

      Default is a SyncTaskExecutor, executing the listeners synchronously in the calling thread.

      Consider specifying an asynchronous TaskExecutor here to not block the caller until all listeners have been executed. However, note that asynchronous execution will not participate in the caller's thread context (class loader, transaction association) unless the TaskExecutor explicitly supports this.

      See Also:
        `SyncTaskExecutor`, `SimpleAsyncTaskExecutor`

    - #### getTaskExecutor

          protected Executor getTaskExecutor()

      Return the current TaskExecutor for this multicaster.

    - #### multicastEvent

          public void multicastEvent(ApplicationEvent event)

      Description copied from interface: `ApplicationEventMulticaster`
      Multicast the given application event to appropriate listeners.
      Parameters:
        `event` - the event to multicast