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javashared-librariesjava-6

Standard interface for no argument function

Is there in Java 6 (or any compatible library) standard interface for no argument function and generic return type.

Something like:

interface Foo<T> {
      T call();
}
Solution

  • It's a Supplier<T> - it takes nothing, and supplies with T. And the abstract method it defines is nice to be called get()

    interface Supplier<T> {
   T get();
}

    Note that in Java8, this (@FunctionalInterface) already exists (it's called Supplier), so if you run your code under Java8, there's no need to define a custom interface.

    Also, if you run your code under some pre-Java8 version, then you can use the Guava's Supplier interface.