How to check if an entiy inside completablefuture is null-CodePudding

I am trying to understand CompletableFurue in Java and I am stuck with the following.

CompletableFuture<String> cf = getString();

I want to check if the String present inside the completable future is "null" or not. How can I do this without using the get() or join() function?

CodePudding user response：

You don't, because the value may not be available yet.

What you can do, is move the check (and follow-up logic) inside the CompletableFuture, using one of its many methods. For instance:

CompletableFuture<Void> cf2 = cf.thenAccept(value -> {
    if (value != null) {
        // do something with the value
    }
});