modernize the CallbackType enum

hibernate-core/src/main/java/org/hibernate/jpa/event/spi/CallbackType.java

@@ -14,24 +14,53 @@
 import jakarta.persistence.PreUpdate;
 
 /**
+ * Enumerates the entity lifecycle callback types defined by JPA.
+ *
  * @author Steve Ebersole
  */
 public enum CallbackType {
-	PRE_UPDATE( PreUpdate.class ),
-	POST_UPDATE( PostUpdate.class ),
-	PRE_PERSIST( PrePersist.class ),
-	POST_PERSIST( PostPersist.class ),
-	PRE_REMOVE( PreRemove.class ),
-	POST_REMOVE( PostRemove.class ),
-	POST_LOAD( PostLoad.class );
-
-	private final Class<? extends Annotation> callbackAnnotation;
-
-	CallbackType(Class<? extends Annotation> callbackAnnotation) {
-		this.callbackAnnotation = callbackAnnotation;
-	}
+	/**
+	 * @see PreUpdate
+	 */
+	PRE_UPDATE,
+	/**
+	 * @see PostUpdate
+	 */
+	POST_UPDATE,
+	/**
+	 * @see PrePersist
+	 */
+	PRE_PERSIST,
+	/**
+	 * @see PostPersist
+	 */
+	POST_PERSIST,
+	/**
+	 * @see PreRemove
+	 */
+	PRE_REMOVE,
+	/**
+	 * @see PostRemove
+	 */
+	POST_REMOVE,
+	/**
+	 * @see PostLoad
+	 */
+	POST_LOAD;
 
+	/**
+	 * The JPA-defined callback annotation type corresponding
+	 * to this lifecycle event type.
+	 */
 	public Class<? extends Annotation> getCallbackAnnotation() {
-		return callbackAnnotation;
+		return switch ( this ) {
+			case PRE_PERSIST -> PrePersist.class;
+			case PRE_UPDATE -> PreUpdate.class;
+			case PRE_REMOVE -> PreRemove.class;
+			case POST_PERSIST -> PostPersist.class;
+			case POST_UPDATE -> PostUpdate.class;
+			case POST_REMOVE -> PostRemove.class;
+			case POST_LOAD -> PostLoad.class;
+		};
 	}
 }

hibernate-core/src/main/java/org/hibernate/jpa/event/spi/package-info.java

@@ -4,6 +4,16 @@
  */
 
 /**
- * The SPI contracts for supporting JPA lifecycle callbacks.
+ * The SPI contracts for supporting JPA lifecycle callbacks and
+ * {@link jakarta.persistence.EntityListeners entity listeners}.
+ *
+ * @see jakarta.persistence.EntityListeners
+ * @see jakarta.persistence.PrePersist
+ * @see jakarta.persistence.PreUpdate
+ * @see jakarta.persistence.PreRemove
+ * @see jakarta.persistence.PostPersist
+ * @see jakarta.persistence.PostUpdate
+ * @see jakarta.persistence.PostRemove
+ * @see jakarta.persistence.PostLoad
  */
 package org.hibernate.jpa.event.spi;