public interface AggregateListener extends Serializable
Modifier and Type | Method and Description |
---|---|
Object |
evaluate(Collection args,
Class[] argClasses,
Collection candidates,
StoreContext ctx)
Return the value of this aggregate.
|
boolean |
expectsArguments()
Return whether this function expects to act on arguments.
|
String |
getTag()
Return the tag that this listener listens for.
|
Class |
getType(Class[] argClasses)
Return the expected type of the result of this listener.
|
String getTag()
boolean expectsArguments()
count()
.Object evaluate(Collection args, Class[] argClasses, Collection candidates, StoreContext ctx)
args
- for each candidate, the value of the arguments to
the function; will be null if this aggregate does
not expect an argument; if this function has
multiple arguments, each element will be an arrayargClasses
- the expected class of each argument elementcandidates
- the candidate objects being evaluatedctx
- the persistence contextUserException
- if this aggregate does not
support in-memory operationCopyright © 2006–2017 Apache Software Foundation. All rights reserved.