Choose the contract supported by each asynchronous operation.
Read the lessons
- Java thenCompose: flatten a dependent asynchronous request
- Java thenCombine: join two independent results without serializing them
- Java applyToEither: use the first normal result of two stages
- Java exceptionallyCompose: recover with another asynchronous stage
- Java CompletableFuture join versus get: preserve failure and interruption contracts
- Java CompletableFuture cancellation: distinguish result status from worker interruption
- Java ExecutorService invokeAll: wait for a bounded batch with a deadline
- Java ExecutorService invokeAny: return one successful result from competing tasks
Common Mistakes
Result completion is separate from task ownership and resource cleanup.