javax.enterprise.inject.spi

Interface ObserverMethod<T>

Type Parameters:

T - the event which should be observed

All Superinterfaces:

Prioritized

public interface ObserverMethod<T>
extends Prioritized

ObserverMethod is the SPI to handle an observer method, which is an event consumer for an event of the given type T. An instance of ObserverMethod exists for every observer method of every enabled bean.

A class may have n observer methods.

Each observer method must have a void return value and exactly one parameter which defines which event it javax.enterprise.event.Observes. The observed event may be further specified by using an optional Qualifier.

Sample:

 public class UserHandler 
 {
   public void afterUserLogin(@Observes UserLoginEvent userHasLoggedIn) 
   {
     // prepare some data for the user, ...
     int userId = userHadLoggedIn.getUserId();
     ...
   }
   
   public void afterAdminLogin(@Observes @Admin UserLoginEvent userHasLoggedIn) 
   {
     // prepare stuff for the admin user
     ...
   }
   
   public void afterUserLogout(@Observes UserLogoutEvent userHasLoggedOut) 
   {
     // cleanup afterwards 
     ...
   }
 }
 

See Also:

Observes

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_PRIORITY The default Priority of any ObserverMethod without a @Priority annotation.

Method Summary

Modifier and Type	Method and Description
Class<?>	getBeanClass()
Set<Annotation>	getObservedQualifiers()
Type	getObservedType()
default int	getPriority() Only synchronous ObserverMethods can be ordered!
Reception	getReception()
TransactionPhase	getTransactionPhase()
default boolean	isAsync()
default void	notify(EventContext<T> eventContext) Call the observer method with the given eventContext.
default void	notify(T event) will actually call the underlying observer method

Field Detail

DEFAULT_PRIORITY

static final int DEFAULT_PRIORITY

The default Priority of any ObserverMethod without a @Priority annotation.

See Also:

Constant Field Values

Method Detail

getBeanClass

Class<?> getBeanClass()

getObservedType

Type getObservedType()

Returns:

the type of the observed event

getObservedQualifiers

Set<Annotation> getObservedQualifiers()

Returns:

the defined Qualifiers plus javax.enterprise.inject.Any

getReception

Reception getReception()

Returns:

either Reception#IF_EXISTS if the observed method must only be called if an instance of the bean which defines the observer method aready exists in the specified context or Reception#ALWAYS.

getTransactionPhase

TransactionPhase getTransactionPhase()

Returns:

the appropriate TransactionPhase for a transactional observer method or TransactionPhase#IN_PROGRESS otherwise.

notify

default void notify(T event)

will actually call the underlying observer method

Parameters:

event -

notify

default void notify(EventContext<T> eventContext)

Call the observer method with the given eventContext.

Parameters:

eventContext -

isAsync

default boolean isAsync()

Returns:

Whether or not this observer method is an async observer. defaults to false for compatibility

getPriority

default int getPriority()

Only synchronous ObserverMethods can be ordered!

Specified by:

getPriority in interface Prioritized

Returns:

The @Priority of this ObserverMethod