org.jboss.gravia.runtime

Interface ServiceReference<T>

Type Parameters:

T - Type of Service.

All Superinterfaces:

Comparable<T>

public interface ServiceReference<T>
extends Comparable<T>

A reference to a service.

The Runtime returns ServiceReference objects from the ModuleContext.getServiceReference and ModuleContext.getServiceReferences methods.

A ServiceReference object may be shared between modules and can be used to examine the properties of the service and to get the service object.

Every service registered in the Runtime has a unique ServiceRegistration object and may have multiple, distinct ServiceReference objects referring to it. ServiceReference objects associated with a ServiceRegistration object have the same hashCode and are considered equal (more specifically, their equals() method will return true when compared).

If the same service object is registered multiple times, ServiceReference objects associated with different ServiceRegistration objects are not equal.

Since:

27-Sep-2013

Author:

thomas.diesler@jboss.com

See Also:

ModuleContext.getServiceReference(Class), ModuleContext.getServiceReference(String), ModuleContext.getServiceReferences(Class, String), ModuleContext.getServiceReferences(String, String), ModuleContext.getService(ServiceReference)

Thread Safety: Thread Safe

Method Summary

Modifier and Type	Method and Description
Module	getModule() Returns the module that registered the service referenced by this ServiceReference object.
Object	getProperty(String key) Returns the property value to which the specified property key is mapped in the properties Dictionary object of the service referenced by this ServiceReference object.
String[]	getPropertyKeys() Returns an array of the keys in the properties Dictionary object of the service referenced by this ServiceReference object.
boolean	isAssignableTo(Module module, String className) Tests if the module that registered the service referenced by this ServiceReference and the specified module use the same source for the package of the specified class name.

Methods inherited from interface java.lang.Comparable

compareTo

Method Detail

getProperty

Object getProperty(String key)

Returns the property value to which the specified property key is mapped in the properties Dictionary object of the service referenced by this ServiceReference object.

Property keys are case-insensitive.

This method must continue to return property values after the service has been unregistered. This is so references to unregistered services (for example, ServiceReference objects stored in the log) can still be interrogated.

Parameters:

key - The property key.

Returns:

The property value to which the key is mapped; null if there is no property named after the key.

getPropertyKeys

String[] getPropertyKeys()

Returns an array of the keys in the properties Dictionary object of the service referenced by this ServiceReference object.

This method will continue to return the keys after the service has been unregistered. This is so references to unregistered services (for example, ServiceReference objects stored in the log) can still be interrogated.

This method is case-preserving; this means that every key in the returned array must have the same case as the corresponding key in the properties Dictionary that was passed to the ModuleContext.registerService(String[],Object,Dictionary) or ServiceRegistration.setProperties(Dictionary) methods.

Returns:

An array of property keys.

getModule

Module getModule()

Returns the module that registered the service referenced by this ServiceReference object.

This method must return null when the service has been unregistered. This can be used to determine if the service has been unregistered.

Returns:

The module that registered the service referenced by this ServiceReference object; null if that service has already been unregistered.

See Also:

ModuleContext.registerService(String[],Object,Dictionary)

isAssignableTo

boolean isAssignableTo(Module module,
                       String className)

Tests if the module that registered the service referenced by this ServiceReference and the specified module use the same source for the package of the specified class name.

This method performs the following checks:

1. Get the package name from the specified class name.
2. For the module that registered the service referenced by this ServiceReference (registrant module); find the source for the package. If no source is found then return true if the registrant module is equal to the specified module; otherwise return false.
3. If the package source of the registrant module is equal to the package source of the specified module then return true; otherwise return false.

Parameters:

module - The Module object to check.

className - The class name to check.

Returns:

true if the module which registered the service referenced by this ServiceReference and the specified module use the same source for the package of the specified class name. Otherwise false is returned.