Class AtomicServiceReference<T>
- java.lang.Object
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- com.ibm.wsspi.kernel.service.utils.AtomicServiceReference<T>
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public class AtomicServiceReference<T> extends java.lang.Object
Small class performing atomic operations to find/retrieve/cache the instance of a DeclarativeServices component reference from service registry via the service reference.Use this to maintain a lazy-resolved reference of cardinality one (single service reference associated with a single, lazily-resolved service instance).
Usage (following OSGi DS naming conventions/patterns):
private final AtomicServiceReference<T> serviceRef = new AtomicServiceReference<T>("referenceName"); protected void activate(ComponentContext ctx) { serviceRef.activate(ctx); } protected void deactivate(ComponentContext ctx) { serviceRef.deactivate(ctx); } protected void setReferenceName(ServiceReference<T> ref) { serviceRef.setReference(ref); } protected void unsetReferenceName(ServiceReference<T> ref) { serviceRef.unsetReference(ref); } private T getReferenceName() { return serviceRef.getService(); }
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Constructor Summary
Constructors Constructor Description AtomicServiceReference(java.lang.String name)
Create a new AtomicServiceReference for the named service.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
activate(org.osgi.service.component.ComponentContext context)
void
deactivate(org.osgi.service.component.ComponentContext context)
org.osgi.framework.ServiceReference<T>
getReference()
T
getService()
T
getServiceWithException()
boolean
setReference(org.osgi.framework.ServiceReference<T> reference)
Update service reference associated with this service.java.lang.String
toString()
boolean
unsetReference(org.osgi.framework.ServiceReference<T> reference)
Clear the service reference associated with this service.
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Method Detail
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activate
public void activate(org.osgi.service.component.ComponentContext context)
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deactivate
public void deactivate(org.osgi.service.component.ComponentContext context)
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setReference
public boolean setReference(org.osgi.framework.ServiceReference<T> reference)
Update service reference associated with this service.- Parameters:
referenceName
- ServiceReference for the target service. Service references are equal if they point to the same service registration, and are ordered by increasing service.ranking and decreasing service.id. ServiceReferences hold no service properties: requests/queries for properties are forwarded onto the backing service registration.- Returns:
- true if this is replacing a previous (non-null) service reference
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unsetReference
public boolean unsetReference(org.osgi.framework.ServiceReference<T> reference)
Clear the service reference associated with this service. This first checks to see whether or not the reference being unset matches the current reference. For Declarative Services dynamic components: if a replacement is available for a dynamic reference, DS will call set with the new reference before calling unset to clear the old one.- Parameters:
reference
- ServiceReference associated with service to be unset.- Returns:
- true if a non-null value was replaced
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getReference
public org.osgi.framework.ServiceReference<T> getReference()
- Returns:
- ServiceReference for the target service. Service references are equal if they point to the same service registration, and are ordered by increasing service.ranking and decreasing service.id. ServiceReferences hold no service properties: requests/queries for properties are forwarded onto the backing service registration.
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getService
public T getService()
- Returns:
- T or null if unavailable
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getServiceWithException
public T getServiceWithException()
- Returns:
- T
- Throws:
java.lang.IllegalStateException
- if the internal state is such that locating the service is not possible or if the service is not retrievable
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toString
public java.lang.String toString()
- Overrides:
toString
in classjava.lang.Object
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