"Fluent interfaces" are nothing new and can be (and are in some projects) used in Java. When done correctly code completion works fine.

As to whether they're worth the addition trouble or not, I sure as heck don't know.

But it's definitely nothing out of the ordinary.

    blobs = createBlob()
        .withinRange(min,max)
        .excluding(a,b,c)
        .asArray()

There are variations, for example where only the last call actually creates, say, a Blob array and where every intermediate call produces something only allowing the next method to be called, so that the IDE autocompletes nearly everything for you and where you won't be able to compile if you miss a single call.

Don't know if the following link is any good but "fluent interfaces" are 15 years old stuff at least by now I'd say:

https://java-design-patterns.com/patterns/fluentinterface/#e...