So far, we have demonstrated some of the useful ways to create a Scala Future and a Promise and displayed the results, using plain println statements. It's for understanding purposes only. In real-time projects, we don't use this approach.
We use the Scala Future API callback methods to check the following things from a Future object or a Promise object:
- Whether it is completed with a success result
- Whether it is completed with a failure
- Whether it is completed successfully or not completed
We use the following functions to check the preceding things, respectively:
- onSuccess (deprecated from Scala 2.12.0 onwards)
- onFailure (deprecated from Scala 2.12.0 onwards)
- onComplete
This example is about how to use a Scala Future's onComplete callback function. It refers to the scala.util.Try construct to check the Future value or exception...
