org.apache.openjpa.slice
Interface DistributionPolicy
- All Known Implementing Classes: 
- DistributionPolicy.Default
- public interface DistributionPolicy 
Policy to select one of the physical databases referred as slice
 in which a given persistent instance will be stored.
  
 The user application is required to implement this interface. Slice will
 invoke the single method of this interface to determine the target slice for
 a newly persistent or a detached instance being merged.
- Author:
- Pinaki Poddar
| Nested Class Summary | 
| static class | DistributionPolicy.DefaultImplements a default distribution policy to store the given 
 instance to a randomly selected available slice.
 | 
 
| Method Summary | 
|  String | distribute(Object pc,
           List<String> slices,
           Object context)Gets the name of the target slice where the given newly persistent or
 the detached, to-be-merged instance will be stored.
 | 
 
distribute
String distribute(Object pc,
                  List<String> slices,
                  Object context)
- Gets the name of the target slice where the given newly persistent or
 the detached, to-be-merged instance will be stored.
 
 If the current state of the given instance is sufficient to determine
 the target slice, return null. In that case, the runtime will callback
 this method again before the instance being flushed to the datastore.
 By then, the policy must be able to determine the target slice.
 
- 
- Parameters:
- pc- The newly persistent or to-be-merged object.
- slices- list of names of the active slices. The ordering of 
 the list is either explicit- openjpa.slice.Namesproperty
 or implicit i.e. alphabetic order of available identifiers if- openjpa.slice.Namesis unspecified.
- context- the generic persistence context managing the given
 instance.
- Returns:
- identifier of the slice. This name must match one of the
 given slice names.
- See Also:
- DistributedConfiguration.getActiveSliceNames()
 
Copyright © 2006-2011 Apache Software Foundation. All Rights Reserved.