|
||||||||||
| PREV CLASS NEXT CLASS | FRAMES NO FRAMES | |||||||||
| SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD | |||||||||
public interface AggregateListener
An aggregate listener aggregates data produced by an ExpressionQuery.
| Method Summary | |
|---|---|
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. |
| Method Detail |
|---|
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 context
UserException - if this aggregate does not
support in-memory operationClass getType(Class[] argClasses)
argClasses - the expected classes of the argument, or null if
no arguments
|
||||||||||
| PREV CLASS NEXT CLASS | FRAMES NO FRAMES | |||||||||
| SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD | |||||||||