java/src/main/com/google/appengine/api/datastore/PostPut.java

   1 // Copyright 2011 Google Inc. All Rights Reserved.
   2
   3 package com.google.appengine.api.datastore;
   4
   5 import java.lang.annotation.ElementType;
   6 import java.lang.annotation.Retention;
   7 import java.lang.annotation.RetentionPolicy;
   8 import java.lang.annotation.Target;
   9
  10 /**
  11  * Identifies a callback method to be invoked after an {@link Entity} of any of
  12  * the specified kinds is written to the datastore.  If {@link #kinds()} is not
  13  * provided the callback will execute for all kinds.  Methods with this
  14  * annotation must return {@code void}, must accept a single argument of type
  15  * {@link PutContext}, must not throw any checked exceptions, must not be
  16  * static, and must belong to a class with a no-arg constructor.  Neither the
  17  * method nor the no-arg constructor of the class to which it belongs are
  18  * required to be public.  Methods with this annotation are free to throw any
  19  * unchecked exception they like.  Throwing an unchecked exception will prevent
  20  * callbacks that have not yet been executed from running, and the exception
  21  * will propagate to the code that invoked the datastore operation that
  22  * resulted in the invocation of the callback.  Throwing an unchecked exception
  23  * from a callback will <b>not</b> have any impact on the result of the
  24  * datastore operation.  Methods with this annotation will not be invoked if
  25  * the datastore operation fails.
  26  *
  27  */
  28 @Target(ElementType.METHOD)
  29 @Retention(RetentionPolicy.RUNTIME)
  30 public @interface PostPut {
  31   /**
  32    * The kinds to which this callback applies.  The default value is an empty
  33    * array, which indicates that the callback should run for all kinds.
  34    *
  35    * @return The kinds to which this callback applies.
  36    */
  37   String[] kinds() default {};
  38 }