Oracle® Coherence Java API Reference
v3.5

E14977-01

com.tangosol.util
Interface MapTrigger

All Superinterfaces:
java.io.Serializable
All Known Implementing Classes:
FilterTrigger

public interface MapTrigger
extends java.io.Serializable

MapTrigger represents a functional agent that allows to validate, reject or modify mutating operations against an underlying map. The trigger operates on an MapTrigger.Entry object that represents a pending mutation that is about to be committed to the underlying map. A MapTrigger could be registered with any ObservableMap using the MapTriggerListener class:

   NamedCache cache = CacheFactory.getCache(sCacheName);
   MapTrigger trigger = new MyCustomTrigger();
   cache.addMapListener(new MapTriggerListener(trigger));
 
Note: In a clustered environment, MapTrigger registration process requires triggers to be serializable and providing a non-default implementation of the hashCode() and equals() methods. Failure to do so may result in duplicate registration and a redundant entry processing by equivalent, but "not equal" MapTrigger objects.

Since:
Coherence 3.4
Author:
cp/gg 2008.03.11
See Also:
FilterTrigger

Nested Class Summary
static interface MapTrigger.Entry
          A MapTrigger Entry represents a pending change to an Entry that is about to committed to the underlying Map.
 
Method Summary
 void process(MapTrigger.Entry entry)
          This method is called before the result of a mutating operation represented by the specified Entry object is committed into the underlying map.
 

Method Detail

process

void process(MapTrigger.Entry entry)
This method is called before the result of a mutating operation represented by the specified Entry object is committed into the underlying map.

An implementation of this method can evaluate the change by analyzing the original and the new value, and can perform any of the following:

Parameters:
entry - a MapTrigger.Entry object that represents the pending change to be committed to the map, as well as the original state of the Entry

Oracle® Coherence Java API Reference
v3.5

E14977-01

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