[BAEL-16531] - Move all the existing articles on "optional" under java-optional

core-java-modules/core-java-9/README.md

@@ -4,13 +4,11 @@ This module contains articles about Java 9 core features
 
 ### Relevant Articles:
 
-- [Method Handles in Java](http://www.baeldung.com/java-method-handles)
-- [Introduction to Chronicle Queue](http://www.baeldung.com/java-chronicle-queue)
-- [Optional orElse Optional](http://www.baeldung.com/java-optional-or-else-optional)
+- [Method Handles in Java](https://www.baeldung.com/java-method-handles)
+- [Introduction to Chronicle Queue](https://www.baeldung.com/java-chronicle-queue)
 - [Iterate Through a Range of Dates in Java](https://www.baeldung.com/java-iterate-date-range)
 - [Initialize a HashMap in Java](https://www.baeldung.com/java-initialize-hashmap)
 - [Immutable Set in Java](https://www.baeldung.com/java-immutable-set)
-- [Filtering a Stream of Optionals in Java](https://www.baeldung.com/java-filter-stream-of-optional)
 
 Note: also contains part of the code for the article
 [How to Filter a Collection in Java](https://www.baeldung.com/java-collection-filtering).

core-java-modules/core-java-9/src/main/java/com/baeldung/optionals/Optionals.java

@@ -1,26 +0,0 @@
-package com.baeldung.optionals;
-
-import java.util.Optional;
-
-public class Optionals {
-
-    public static <T> Optional<T> or(Optional<T> optional, Optional<T> fallback) {
-        return optional.isPresent() ? optional : fallback;
-    }
-
-    public static Optional<String> getName(Optional<String> name) {
-        return name.or(() -> getCustomMessage());
-    }
-
-    public static com.google.common.base.Optional<String> getOptionalGuavaName(com.google.common.base.Optional<String> name) {
-        return name.or(getCustomMessageGuava());
-    }
-
-    private static Optional<String> getCustomMessage() {
-        return Optional.of("Name not provided");
-    }
-
-    private static com.google.common.base.Optional<String> getCustomMessageGuava() {
-        return com.google.common.base.Optional.of("Name not provided");
-    }
-} 

core-java-modules/core-java-9/src/test/java/com/baeldung/java9/Java9OptionalsStreamUnitTest.java

@@ -1,61 +0,0 @@
-package com.baeldung.java9;
-
-import static org.junit.Assert.assertEquals;
-
-import java.util.Arrays;
-import java.util.List;
-import java.util.Optional;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
-
-import org.junit.Test;
-
-public class Java9OptionalsStreamUnitTest {
-
-    private static List<Optional<String>> listOfOptionals = Arrays.asList(Optional.empty(), Optional.of("foo"), Optional.empty(), Optional.of("bar"));
-
-    @Test
-    public void filterOutPresentOptionalsWithFilter() {
-        assertEquals(4, listOfOptionals.size());
-
-        List<String> filteredList = listOfOptionals.stream().filter(Optional::isPresent).map(Optional::get).collect(Collectors.toList());
-
-        assertEquals(2, filteredList.size());
-        assertEquals("foo", filteredList.get(0));
-        assertEquals("bar", filteredList.get(1));
-    }
-
-    @Test
-    public void filterOutPresentOptionalsWithFlatMap() {
-        assertEquals(4, listOfOptionals.size());
-
-        List<String> filteredList = listOfOptionals.stream().flatMap(o -> o.isPresent() ? Stream.of(o.get()) : Stream.empty()).collect(Collectors.toList());
-        assertEquals(2, filteredList.size());
-
-        assertEquals("foo", filteredList.get(0));
-        assertEquals("bar", filteredList.get(1));
-    }
-
-    @Test
-    public void filterOutPresentOptionalsWithFlatMap2() {
-        assertEquals(4, listOfOptionals.size());
-
-        List<String> filteredList = listOfOptionals.stream().flatMap(o -> o.map(Stream::of).orElseGet(Stream::empty)).collect(Collectors.toList());
-        assertEquals(2, filteredList.size());
-
-        assertEquals("foo", filteredList.get(0));
-        assertEquals("bar", filteredList.get(1));
-    }
-
-    @Test
-    public void filterOutPresentOptionalsWithJava9() {
-        assertEquals(4, listOfOptionals.size());
-
-        List<String> filteredList = listOfOptionals.stream().flatMap(Optional::stream).collect(Collectors.toList());
-
-        assertEquals(2, filteredList.size());
-        assertEquals("foo", filteredList.get(0));
-        assertEquals("bar", filteredList.get(1));
-    }
-
-}

core-java-modules/core-java-9/src/test/java/com/baeldung/optionals/OptionalsTest.java

@@ -1,51 +0,0 @@
-package com.baeldung.optionals;
-
-import static org.junit.Assert.assertEquals;
-
-import java.util.Optional;
-
-import org.junit.Test;
-
-public class OptionalsTest {
-
-    @Test
-    public void givenOptional_whenEmptyValue_thenCustomMessage() {
-        assertEquals(Optional.of("Name not provided"), Optionals.getName(Optional.ofNullable(null)));
-    }
-
-    @Test
-    public void givenOptional_whenValue_thenOptional() {
-        String name = "Filan Fisteku";
-        Optional<String> optionalString = Optional.ofNullable(name);
-        assertEquals(optionalString, Optionals.getName(optionalString));
-    }
-    
-    @Test
-    public void givenOptional_whenValue_thenOptionalGeneralMethod() {
-        String name = "Filan Fisteku";
-        String missingOptional = "Name not provided";
-        Optional<String> optionalString = Optional.ofNullable(name);
-        Optional<String> fallbackOptionalString = Optional.ofNullable(missingOptional);
-        assertEquals(optionalString, Optionals.or(optionalString, fallbackOptionalString));
-    }
-    
-    @Test
-    public void givenEmptyOptional_whenValue_thenOptionalGeneralMethod() {
-        String missingOptional = "Name not provided";
-        Optional<String> optionalString = Optional.empty();
-        Optional<String> fallbackOptionalString = Optional.ofNullable(missingOptional);
-        assertEquals(fallbackOptionalString, Optionals.or(optionalString, fallbackOptionalString));
-    }
-
-    @Test
-    public void givenGuavaOptional_whenInvoke_thenOptional() {
-        String name = "Filan Fisteku";
-        com.google.common.base.Optional<String> stringOptional = com.google.common.base.Optional.of(name);
-        assertEquals(stringOptional, Optionals.getOptionalGuavaName(stringOptional));
-    }
-
-    @Test
-    public void givenGuavaOptional_whenNull_thenDefaultText() {
-        assertEquals(com.google.common.base.Optional.of("Name not provided"), Optionals.getOptionalGuavaName(com.google.common.base.Optional.fromNullable(null)));
-    }
-}