DocumentationJava Profiler 9.0 HelpProbes: extendable profiling and monitoringMonitoring method invocation eventsCallback method parameter annotation @ReturnValue

Callback parameter annotated with @ReturnValue allows to access method return value.

In which callbacks can be used

Parameter annotated with @ReturnValue can be used in onReturn() only.

Declaration type

Parameter annotated with @ReturnValue can be declared as a reference type or as a primitive type.

If the callback parameter is declared as java.lang.Object, it will be assigned with object reference as is if the actual parameter type is a reference type, or with a boxed value if the actual parameter type is primitive.

If the callback parameter is declared as some reference type other than java.lang.Object, it will be assigned with the actual method parameter value only if it is declared as strictly the same type. Otherwise the callback parameter value will be null.

If the callback parameter is declared as a primitive type, it will be assigned with the actual method parameter value only if it is declared as strictly the same type. Otherwise it will be assigned with 0; no type conversions will be performed. For example, int will not be cast to long.

Note: The type matching rules for @ReturnValue are similar to ones for @Param and differ from the rules for @This