KeyRange (Google App Engine API for Java)

com.google.appengine.api.datastore

Class KeyRange

• java.lang.Object
• • com.google.appengine.api.datastore.KeyRange

• All Implemented Interfaces:

  java.io.Serializable, java.lang.Iterable<Key>

  ---

  
  

  public final class KeyRange
  extends java.lang.Object
  implements java.lang.Iterable<Key>, java.io.Serializable

  Represents a range of unique datastore identifiers from getStart().getId() to getEnd().getId() inclusive. If an instance of this class is the result of a call to DatastoreService.allocateIds(), the Keys returned by this instance have been consumed in the datastore's id-space and are guaranteed never to be reused.
  This class can be used to construct Entities with Keys that have specific id values without fear of the datastore creating new records with those same ids at a later date. This can be helpful as part of a data migration or large bulk upload where you may need to preserve existing ids and relationships between entities.
  This class is threadsafe but the Iterators returned by iterator() are not.

  See Also:

  Serialized Form

• • Constructor Summary

    Constructors 

    Constructor and Description
    KeyRange(Key parent, java.lang.String kind, long start, long end)

  • Method Summary

    All Methods Instance Methods Concrete Methods 

    Modifier and Type	Method and Description
    boolean	equals(java.lang.Object obj)
    Key	getEnd()
    long	getSize()
    Key	getStart()
    int	hashCode()
    java.util.Iterator<Key>	iterator()

    • Methods inherited from class java.lang.Object

      getClass, notify, notifyAll, toString, wait, wait, wait

    • Methods inherited from interface java.lang.Iterable

      forEach, spliterator

• • Constructor Detail

    • KeyRange

      public KeyRange(Key parent,
                      java.lang.String kind,
                      long start,
                      long end)

  • Method Detail

    • getStart

      public Key getStart()

      Returns:

      The first Key in the range.

    • getEnd

      public Key getEnd()

      Returns:

      The last Key in the range.

    • getSize

      public long getSize()

      Returns:

      The size of the range.

    • iterator

      public java.util.Iterator<Key> iterator()

      Specified by:

      iterator in interface java.lang.Iterable<Key>

    • equals

      public boolean equals(java.lang.Object obj)

      Overrides:

      equals in class java.lang.Object

    • hashCode

      public int hashCode()

      Overrides:

      hashCode in class java.lang.Object