Data commit

Task/Monads-Maybe-monad/Java/monads-maybe-monad.java

@@ -0,0 +1,29 @@
+import java.util.Optional;
+
+public final class MonadMaybe {
+
+	public static void main(String[] aArgs) {
+	    System.out.println(doubler(5).flatMap(MonadMaybe::stringify).get());
+	
+	    System.out.println(doubler(2).flatMap(MonadMaybe::stringifyNullable).get());
+	
+	    Optional<String> option = doubler(0).flatMap(MonadMaybe::stringifyNullable);
+	
+	    String result = option.isPresent() ? option.get() : "Result is Null";
+	
+	    System.out.println(result);
+	}
+	
+	private static Optional<Integer> doubler(int aN) {
+		return Optional.of(2 * aN);
+	}
+
+	private static Optional<String> stringify(int aN) {
+		return Optional.of("A".repeat(aN));
+	}
+
+	private static Optional<String> stringifyNullable(int aN) {
+		return ( aN > 0 ) ? Optional.ofNullable("A".repeat(aN)) : Optional.ofNullable(null);
+	}
+
+}