org.glassfish.hk2.api.InstanceLifecycleListener Maven / Gradle / Ivy
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package org.glassfish.hk2.api;
import org.jvnet.hk2.annotations.Contract;
/**
* This processor is called for certain events in the lifecycle of instances
* of services.
*
* This listener is concerned with instances of services, whereas the
* {@link ValidationService} is concerned with the descriptors for services.
*
* An implementation of InstanceLifecycleListener must be in the Singleton scope.
* Implementations of InstanceLifecycleListener will be instantiated as soon as
* they are added to HK2 in order to avoid deadlocks and circular references.
* Therefore it is recommended that implementations of InstanceLifecycleListener
* make liberal use of {@link javax.inject.Provider} or {@link IterableProvider}
* when injecting dependent services so that these services are not instantiated
* when the InstanceLifecycleListener is created
*
* @author jwells
*/
@Contract
public interface InstanceLifecycleListener {
/**
* This returns a filter that tells the system whether a particular descriptor should be handled by this lifecycle
* listener. The filter can be called at any time
*
* @return The filter that tells the system if this listener applies to this descriptor. If this returns null then
* this Listener will apply to ALL descriptors.
*/
public Filter getFilter();
/**
* This method will be called when any lifecycle event occurs. The currently supported
* lifecycle events are PRE_PRODUCTION, POST_PRODUCTION and PRE_DESTRUCTION. Code should be written to
* allow for future events to be generated. This method should not throw exceptions
*
* @param lifecycleEvent The event that has occurred, will not be null
*/
public void lifecycleEvent(InstanceLifecycleEvent lifecycleEvent);
}