AbstractAnnotableRegistration.java

package sk.stuba.fiit.perconik.core.persistence.data;

import java.lang.annotation.Annotation;
import java.util.List;

import sk.stuba.fiit.perconik.core.Registrables;
import sk.stuba.fiit.perconik.core.persistence.AnnotableRegistration;
import sk.stuba.fiit.perconik.utilities.reflect.annotation.Annotable;

/**
 * An abstract implementation of the {@link AnnotableRegistration} interface.
 *
 * @author Pavol Zbell
 * @since 1.0
 */
abstract class AbstractAnnotableRegistration extends AbstractRegistration implements AnnotableRegistration {
  private transient volatile Annotable annotable;

  /**
   * Constructor for use by subclasses.
   */
  protected AbstractAnnotableRegistration() {}

  private final Annotable annotable() {
    Annotable annotable = this.annotable;

    if (annotable == null) {
      synchronized (this) {
        annotable = this.annotable;

        if (annotable == null) {
          annotable = this.annotable = Registrables.toAnnotable(this.registrable().getClass());
        }
      }
    }

    return annotable;
  }

  public final boolean hasAnnotation(final Class<? extends Annotation> type) {
    return this.annotable().hasAnnotation(type);
  }

  public final <A extends Annotation> A getAnnotation(final Class<A> type) {
    return this.annotable().getAnnotation(type);
  }

  public final List<Annotation> getAnnotations() {
    return this.annotable().getAnnotations();
  }
}