''SerializableOptional' now has a factory method 'empty'.

Author: nicolaiparlog

src/main/java/org/codefx/libfx/serialization/SerializableOptional.java

@@ -116,6 +116,18 @@ public static <T extends Serializable> SerializableOptional<T> fromOptional(Opti
 		return new SerializableOptional<>(optional);
 	}
 
+	/**
+	 * Creates a serializable optional which wraps an empty optional.
+	 *
+	 * @param <T>
+	 *            the type of the non-existent value
+	 * @return a {@link SerializableOptional} which wraps an {@link Optional#empty() empty} {@link Optional}
+	 * @see Optional#of(Object)
+	 */
+	public static <T extends Serializable> SerializableOptional<T> empty() {
+		return new SerializableOptional<>(Optional.empty());
+	}
+
 	/**
 	 * Creates a serializable optional for the specified value by wrapping it in an {@link Optional}.
 	 *

src/test/java/org/codefx/libfx/serialization/SerializableOptionalTest.java

@@ -47,6 +47,16 @@ public void testFromNonEmptyOptional() {
 		assertEquals(nonEmpty, nonEmptySerializable.asOptional());
 	}
 
+	/**
+	 * Tests whether an empty {@code SerializableOptional} can be created.
+	 */
+	@Test
+	public void testEmpty() {
+		SerializableOptional<String> emptySerializable = SerializableOptional.empty();
+
+		assertFalse(emptySerializable.asOptional().isPresent());
+	}
+
 	/**
 	 * Tests whether calling {@link SerializableOptional#of(Serializable) of(null)} throws a
 	 * {@link NullPointerException}.
@@ -63,9 +73,9 @@ public void testOfWithNull() {
 	@Test
 	public void testOfWithNonNull() {
 		String notNull = "Not Null!";
-		SerializableOptional<String> emptySerializable = SerializableOptional.of(notNull);
+		SerializableOptional<String> presentSerializable = SerializableOptional.of(notNull);
 
-		assertEquals(notNull, emptySerializable.asOptional().get());
+		assertEquals(notNull, presentSerializable.asOptional().get());
 	}
 
 	/**
@@ -86,9 +96,9 @@ public void testOfNullableWithNull() {
 	@Test
 	public void testOfNullableWithNonNull() {
 		String notNull = "Not Null!";
-		SerializableOptional<String> emptySerializable = SerializableOptional.ofNullable(notNull);
+		SerializableOptional<String> presentSerializable = SerializableOptional.ofNullable(notNull);
 
-		assertEquals(notNull, emptySerializable.asOptional().get());
+		assertEquals(notNull, presentSerializable.asOptional().get());
 	}
 
 	// #end CONSTRUCTION