http://www.avaje.org/java8-parent/ebean-annotation: For open source java artifacts.
  • Rob Bygrave 
package io.ebean.annotation;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;


For a timestamp property that is set to the datetime when the entity is
created/inserted.


This is effectively an alias for @CreatedTimestamp and added to hint
towards a better naming convention (WhenCreated, WhenModified).




An alternative to using this annotation would be to use insertable=false,
updateable=false with @Column and have the DB insert the current time
(default value on the DB column is SYSTIME etc).




The downside to this approach is that the inserted entity does not have the
timestamp value after the insert has occurred. You need to fetch the entity
back to get the inserted timestamp if you want to used it.





Example:



  @WhenCreated
  Timestamp whenCreated;



/**
 * For a timestamp property that is set to the datetime when the entity is
 * created/inserted.
 * <p>
 * This is effectively an alias for @CreatedTimestamp and added to hint
 * towards a better naming convention (WhenCreated, WhenModified).
 * </p>
 * <p>
 * An alternative to using this annotation would be to use insertable=false,
 * updateable=false with @Column and have the DB insert the current time
 * (default value on the DB column is SYSTIME etc).
 * </p>
 * <p>
 * The downside to this approach is that the inserted entity does not have the
 * timestamp value after the insert has occurred. You need to fetch the entity
 * back to get the inserted timestamp if you want to used it.
 * </p>
 * <p>
 * <h3>Example:</h3>
 * <pre>{@code
 *
 *   @WhenCreated
 *   Timestamp whenCreated;
 *
 * }</pre>
 */
@Target({ElementType.FIELD, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface WhenCreated {

}