227. Extending StructuredTaskScope

We cannot extend StructuredTaskScope.ShutdownOnSuccess (Chapter 10, Problem 221) or ShutdownOnFailure (Chapter 10, Problem 222) since these are final classes. But, we can extend StructuredTaskScope and provide a custom behavior via its handleComplete() method.

Let’s assume that we want to travel from our current location to a certain destination in our town:

String loc = "124 NW Bobcat L, St. Robert"; // from user
String dest = "129 West 81st Street";       // from user

On our phone, we have an application that can query a ridesharing service and the public transport service. The ridesharing service can simultaneously query multiple ridesharing servers to find the cheapest offer. On the other hand, the public transport service can simultaneously query the public transport servers to find the offer that leaves the earliest, no matter whether it is by bus, train, tram, or subway. In a diagram, we can represent...