What are the differences between Java promises and callbacks?

What are the differences between Java promises and callbacks?

Java promises and callbacks are both used for handling asynchronous operations, but they differ in structure and usability. Callbacks are functions passed as arguments to be executed later, while promises represent a value that may be available now or in the future.

Can you give me an example of each?

Sure! A callback example would be using a method that takes a function as an argument to execute after a task completes. A promise example would be using CompletableFuture in Java, which allows you to chain operations and handle success or failure more elegantly.

Which one is better to use?

It depends on the context. Promises are generally preferred for their readability and ability to handle multiple asynchronous operations more cleanly, while callbacks can be simpler for straightforward tasks.

Are there any downsides to using promises?

Yes, while promises improve readability, they can lead to complexity if not managed properly, especially with error handling and chaining.