Interface ServiceReference<S>
- Type Parameters:
S
- Type of Service.
- All Superinterfaces:
BundleReference
,Comparable<Object>
The Framework returns ServiceReference
objects from the
BundleContext.getServiceReference
and
BundleContext.getServiceReferences
methods.
A ServiceReference
object may be shared between bundles and can be
used to examine the properties of the service and to get the service object.
Every service registered in the Framework 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.
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Method Summary
Modifier and TypeMethodDescription<A> A
Adapt thisServiceReference
object to the specified type.int
Compares thisServiceReference
with the specifiedServiceReference
for order.Returns the bundle that registered the service referenced by thisServiceReference
object.Returns a copy of the properties of the service referenced by thisServiceReference
object.getProperty
(String key) Returns the property value to which the specified property key is mapped in the propertiesDictionary
object of the service referenced by thisServiceReference
object.String[]
Returns an array of the keys in the propertiesDictionary
object of the service referenced by thisServiceReference
object.Bundle[]
Returns the bundles that are using the service referenced by thisServiceReference
object.boolean
isAssignableTo
(Bundle bundle, String className) Tests if the bundle that registered the service referenced by thisServiceReference
and the specified bundle use the same source for the package of the specified class name.
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Method Details
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getProperty
Returns the property value to which the specified property key is mapped in the propertiesDictionary
object of the service referenced by thisServiceReference
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.
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getPropertyKeys
String[] getPropertyKeys()Returns an array of the keys in the propertiesDictionary
object of the service referenced by thisServiceReference
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 theBundleContext.registerService(String[],Object,Dictionary)
orServiceRegistration.setProperties(Dictionary)
methods.- Returns:
- An array of property keys.
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getBundle
Bundle getBundle()Returns the bundle that registered the service referenced by thisServiceReference
object.This method must return
null
when the service has been unregistered. This can be used to determine if the service has been unregistered.- Specified by:
getBundle
in interfaceBundleReference
- Returns:
- The bundle that registered the service referenced by this
ServiceReference
object;null
if that service has already been unregistered. - See Also:
-
getUsingBundles
Bundle[] getUsingBundles()Returns the bundles that are using the service referenced by thisServiceReference
object. Specifically, this method returns the bundles whose usage count for that service is greater than zero.- Returns:
- An array of bundles whose usage count for the service referenced
by this
ServiceReference
object is greater than zero;null
if no bundles are currently using that service. - Since:
- 1.1
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isAssignableTo
Tests if the bundle that registered the service referenced by thisServiceReference
and the specified bundle use the same source for the package of the specified class name.This method performs the following checks:
- If the specified bundle is equal to the bundle that registered the
service referenced by this
ServiceReference
(registrant bundle) returntrue
. - Get the package name from the specified class name.
- For the specified bundle; find the source for the package. If no
source is found then return
true
(use of reflection is assumed by the specified bundle). - For the registrant bundle; find the source for the package. If the
package source is found then return
true
if the package source equals the package source of the specified bundle; otherwise returnfalse
. - If no package source is found for the registrant bundle then
determine the package source based on the service object. If the service
object is a
ServiceFactory
and the factory implementation is not from the registrant bundle returntrue
; otherwise attempt to find the package source based on the service object class. If the package source is found and is equal to package source of the specified bundle returntrue
; otherwise returnfalse
.
- Parameters:
bundle
- TheBundle
object to check.className
- The class name to check.- Returns:
true
if the bundle which registered the service referenced by thisServiceReference
and the specified bundle use the same source for the package of the specified class name. Otherwisefalse
is returned.- Throws:
IllegalArgumentException
- If the specifiedBundle
was not created by the same framework instance as thisServiceReference
.- Since:
- 1.3
- If the specified bundle is equal to the bundle that registered the
service referenced by this
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compareTo
Compares thisServiceReference
with the specifiedServiceReference
for order.If this
ServiceReference
and the specifiedServiceReference
have the sameservice id
they are equal. ThisServiceReference
is less than the specifiedServiceReference
if it has a lowerservice ranking
and greater if it has a higher service ranking. Otherwise, if thisServiceReference
and the specifiedServiceReference
have the sameservice ranking
, thisServiceReference
is less than the specifiedServiceReference
if it has a higherservice id
and greater if it has a lower service id.- Specified by:
compareTo
in interfaceComparable<S>
- Parameters:
reference
- TheServiceReference
to be compared.- Returns:
- Returns a negative integer, zero, or a positive integer if this
ServiceReference
is less than, equal to, or greater than the specifiedServiceReference
. - Throws:
IllegalArgumentException
- If the specifiedServiceReference
was not created by the same framework instance as thisServiceReference
.- Since:
- 1.4
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getProperties
Dictionary<String,Object> getProperties()Returns a copy of the properties of the service referenced by thisServiceReference
object.This method will continue to return the properties 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.The returned
Dictionary
object:- Must map property values by using property keys in a case-insensitive manner.
- Must return property keys is a case-preserving manner. This
means that the keys must have the same case as the corresponding key in
the properties
Dictionary
that was passed to theBundleContext.registerService(String[],Object,Dictionary)
orServiceRegistration.setProperties(Dictionary)
methods. - Is the property of the caller and can be modified by the caller but
any changes are not reflected in the properties of the service.
ServiceRegistration.setProperties(Dictionary)
must be called to modify the properties of the service.
- Returns:
- A copy of the properties of the service referenced by this
ServiceReference
object - Since:
- 1.9
-
adapt
Adapt thisServiceReference
object to the specified type.Adapting this
ServiceReference
object to the specified type may require certain checks, including security checks, to succeed. If a check does not succeed, then thisServiceReference
object cannot be adapted andnull
is returned.- Type Parameters:
A
- The type to which thisServiceReference
object is to be adapted.- Parameters:
type
- Class object for the type to which thisServiceReference
object is to be adapted.- Returns:
- The object, of the specified type, to which this
ServiceReference
object has been adapted ornull
if thisServiceReference
object cannot be adapted to the specified type. - Throws:
SecurityException
- If the caller does not have the appropriateAdaptPermission[type,this,ADAPT]
, and the Java Runtime Environment supports permissions.- Since:
- 1.10
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