Learning RxJava - Second Edition

Making a Supplier a lambda

Lambda expressions can also implement methods that return items. For instance, the Supplier interface introduced in Java 8 (and originally introduced in Google Guava) has an abstract get() method that returns a T item for a given Supplier<T>. If we have a Supplier<List<String>> whose get() method returns List<String>, we can implement it using an old-fashioned anonymous class as follows:

import java.util.ArrayList;import java.util.List;import java.util.function.Supplier;public class A_05 {    public static void main(String[] args) {        Supplier<List<String>> listGenerator =                new Supplier<List<String>>() {                    @Override                    public List<String> get() {                        return new ArrayList<>();                    }                };        List<String> myList = listGenerator.get();    }