快速转义闭包以及如何在Java中执行

Question

I'm developing an app for both iOS and Java and in my swift program I have a function that uses an escaping closure that passes an array of strings. In swift, it's func definition goes as

func foo(uid: String, onComplete: @escaping([String]) -> Void { 
    onComplete(someStringArray)
}

and its func call is

class.foo(uid: player1, onComplete { (stringArray) in {
    do something with stringArray
}

My main focus is now figuring that out for Java. The BIG issue is I'm using Google's Firebase Database which loads data asynchronously so simply making a return function won't work since the return will be called before all the data is loaded. I've heard of maybe call backs, but I figured I'd ask here first before I spend precious hours on the wrong task. I'm thinking the Java version would be

void foo(String uid, onComplete...) { 
onComplete(someStringArray)
}

Anyways I hope I was as detailed as possible and appreciate any help at all! -Ben

Answer 1

You can use Lambda Expresions expressions.

Forgive my function naming, but here is an example:

public class LambdaExample{

    interface Description {
        void describeThis(String str);
    }

    public static void getDescription(Description description, String str){
        description.describeThis(str);
    }

    public static void main(String []args){
        getDescription(new Description() {
            @Override
            public void describeThis(String str) {
                System.out.println(str + " is handsome");  // Meow2x is handsome
            }
        }, "Meow2x");
    }
}