org.glassfish.jersey.internal.inject.ReferencingFactory Maven / Gradle / Ivy
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package org.glassfish.jersey.internal.inject;
import org.glassfish.hk2.api.Factory;
import org.glassfish.jersey.internal.util.collection.Ref;
import org.glassfish.jersey.internal.util.collection.Refs;
import javax.inject.Provider;
/**
* Factory that provides injection of the referenced instance.
*
* @param
* @author Marek Potociar (marek.potociar at oracle.com)
*/
public abstract class ReferencingFactory implements Factory {
private static class EmptyReferenceFactory implements Factory> {
@Override
public Ref provide() {
return Refs.emptyRef();
}
@Override
public void dispose(Ref instance) {
//not used
}
}
private static class InitializedReferenceFactory implements Factory> {
private final T initialValue;
public InitializedReferenceFactory(T initialValue) {
this.initialValue = initialValue;
}
@Override
public Ref provide() {
return Refs.of(initialValue);
}
@Override
public void dispose(Ref instance) {
//not used
}
}
private final Provider> referenceFactory;
/**
* Create new referencing injection factory.
*
* @param referenceFactory reference provider backing the factory.
*/
public ReferencingFactory(Provider> referenceFactory) {
this.referenceFactory = referenceFactory;
}
@Override
public T provide() {
return referenceFactory.get().get();
}
@Override
public void dispose(T instance) {
//not used
}
/**
* Get a reference factory providing an empty reference.
*
* @param reference type.
* @return reference factory providing an empty reference.
*/
public static Factory> referenceFactory() {
return new EmptyReferenceFactory();
}
/**
* Get a reference factory providing an initialized reference.
*
* @param reference type.
* @param initialValue initial value stored in the reference provided
* by the returned factory.
* @return reference factory providing a reference initialized with an
* {@code initialValue}.
*/
public static Factory> referenceFactory(T initialValue) {
if (initialValue == null) {
return new EmptyReferenceFactory();
}
return new InitializedReferenceFactory(initialValue);
}
}