org.glassfish.hk2.api.ValidationService Maven / Gradle / Ivy
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package org.glassfish.hk2.api;
import org.jvnet.hk2.annotations.Contract;
/**
* This service can be used to add validation points to Descriptors.
*
* An implementation of ValidationService must be in the Singleton scope.
* Implementations of ValidationService 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 ValidationService
* make liberal use of {@link javax.inject.Provider} or {@link IterableProvider}
* when injecting dependent services so that these services are not instantiated
* when the ValidationService is created
*
* @author jwells
*
*/
@Contract
public interface ValidationService {
/**
* This filter will be run at least once per descriptor at the point that the descriptor
* is being looked up, either with the {@link ServiceLocator} API or due to
* an @Inject resolution. The decision made by this filter will be cached and
* used every time that Descriptor is subsequently looked up. No validation checks
* should be done in the returned filter, it is purely meant to limit the
* {@link Descriptor}s that are passed into the validator.
*
* Descriptors passed to this filter may or may not be reified. The filter should try as
* much as possible to do its work without reifying the descriptor.
*
* The filter may be run more than once on a descriptor if some condition caused
* the cache of results per descriptor to become invalidated.
*
* @return The filter to be used to determine if the validators associated with this
* service should be called when the passed in {@link Descriptor} is looked up
*/
public Filter getLookupFilter();
/**
* Returns the {@link Validator} that will be run whenever
* a {@link Descriptor} that passed the filter is to be looked up with the API
* or injected into an injection point, or on any bind or unbind operation.
* If this method returns false then the operation will not proceed.
*
* @return A non-null validator
*/
public Validator getValidator();
}