Top Description Methods
org.osgi.util.tracker

public Interface ServiceTrackerCustomizer<S, T>

Known Direct Implementers
org.osgi.util.tracker.ServiceTracker
Annotations
@ConsumerType
Type Parameters
<S>
The type of the service being tracked.
<T>
The type of the tracked object.
Imports
org.osgi.annotation.versioning.ConsumerType, org.osgi.framework.ServiceReference
The ServiceTrackerCustomizer interface allows a ServiceTracker to customize the service objects that are tracked. A ServiceTrackerCustomizer is called when a service is being added to a ServiceTracker. The ServiceTrackerCustomizer can then return an object for the tracked service. A ServiceTrackerCustomizer is also called when a tracked service is modified or has been removed from a ServiceTracker.

The methods in this interface may be called as the result of a ServiceEvent being received by a ServiceTracker. Since ServiceEvents are synchronously delivered by the Framework, it is highly recommended that implementations of these methods do not register ( BundleContext.registerService), modify ( ServiceRegistration.setProperties) or unregister ( ServiceRegistration.unregister) a service while being synchronized on any object.

The ServiceTracker class is thread-safe. It does not call a ServiceTrackerCustomizer while holding any locks. ServiceTrackerCustomizer implementations must also be thread-safe.

Author
$Id: 4617b2c5a0fba74a1a48db7188a3c946c672fefb $

Method Summary

Modifier and TypeMethod and Description
public T

Returns:

The service object to be tracked for the specified referenced service or null if the specified referenced service should not be tracked.
addingService(ServiceReference<S>
The reference to the service being added to the ServiceTracker.
reference)

A service is being added to the ServiceTracker.

public void
modifiedService(ServiceReference<S>
The reference to the service that has been modified.
reference, T
The service object for the specified referenced service.
service)

A service tracked by the ServiceTracker has been modified.

public void
removedService(ServiceReference<S>
The reference to the service that has been removed.
reference, T
The service object for the specified referenced service.
service)

A service tracked by the ServiceTracker has been removed.

Method Detail

addingServiceback to summary
public T addingService(ServiceReference<S> reference)

A service is being added to the ServiceTracker.

This method is called before a service which matched the search parameters of the ServiceTracker is added to the ServiceTracker. This method should return the service object to be tracked for the specified ServiceReference. The returned service object is stored in the ServiceTracker and is available from the getService and getServices methods.

Parameters
reference:ServiceReference<S>

The reference to the service being added to the ServiceTracker.

Returns:T

The service object to be tracked for the specified referenced service or null if the specified referenced service should not be tracked.

modifiedServiceback to summary
public void modifiedService(ServiceReference<S> reference, T service)

A service tracked by the ServiceTracker has been modified.

This method is called when a service being tracked by the ServiceTracker has had it properties modified.

Parameters
reference:ServiceReference<S>

The reference to the service that has been modified.

service:T

The service object for the specified referenced service.

removedServiceback to summary
public void removedService(ServiceReference<S> reference, T service)

A service tracked by the ServiceTracker has been removed.

This method is called after a service is no longer being tracked by the ServiceTracker.

Parameters
reference:ServiceReference<S>

The reference to the service that has been removed.

service:T

The service object for the specified referenced service.