Callable vs Supplier interface in java

Question

The Callable and Supplier functional interfaces in java.util.concurrent and java.util.function packages respectively have the

Answer 1

For Runnable and Callable, they've been parts of the concurrent package since Java 6. It implies that both of them are ready to be submitted to an Executor and run asynchronously. Here Callable has a specific usage.

While for Runnable(0 in 0 out), Supplier(0 in 1 out), Consumer(1 in 0 out) and Function(1 in 1 out), they've been parts of the functional feature since Java 8. All of them are ready to be handled by something lambda friendly, like CompletableFuture. Here Supplier just means a function without any input param but has a return value, which is highly abstract.