Java 11 migrate all remaining s (#1120)

* Moves saga to Java 11

* Moves semaphore to Java 11

* Moves servant to Java 11

* Moves serverless to Java 11

* Moves service-layer to Java 11

* Moves service-locator to Java 11

* Moves sharding to Java 11

* Moves singleton to Java 11

* Moves spatial-partition to Java 11

* Moves specification to Java 11

* Moves state to Java 11

* Moves step-builder to Java 11

* Moves strategy to Java 11

* Moves subclass-sandbox to Java 11

* Fixes checkstyle issues

step-builder/src/main/java/com/iluwatar/stepbuilder/App.java

@@ -67,21 +67,34 @@ public class App {
    */
   public static void main(String[] args) {
 
-    var warrior =
-        CharacterStepBuilder.newBuilder().name("Amberjill").fighterClass("Paladin")
-            .withWeapon("Sword").noAbilities().build();
+    var warrior = CharacterStepBuilder
+        .newBuilder()
+        .name("Amberjill")
+        .fighterClass("Paladin")
+        .withWeapon("Sword")
+        .noAbilities()
+        .build();
 
     LOGGER.info(warrior.toString());
 
-    var mage =
-        CharacterStepBuilder.newBuilder().name("Riobard").wizardClass("Sorcerer")
-            .withSpell("Fireball").withAbility("Fire Aura").withAbility("Teleport")
-            .noMoreAbilities().build();
+    var mage = CharacterStepBuilder
+        .newBuilder()
+        .name("Riobard")
+        .wizardClass("Sorcerer")
+        .withSpell("Fireball")
+        .withAbility("Fire Aura")
+        .withAbility("Teleport")
+        .noMoreAbilities()
+        .build();
 
     LOGGER.info(mage.toString());
 
-    var thief =
-        CharacterStepBuilder.newBuilder().name("Desmond").fighterClass("Rogue").noWeapon().build();
+    var thief = CharacterStepBuilder
+        .newBuilder()
+        .name("Desmond")
+        .fighterClass("Rogue")
+        .noWeapon()
+        .build();
 
     LOGGER.info(thief.toString());
   }

step-builder/src/main/java/com/iluwatar/stepbuilder/Character.java

@@ -91,15 +91,15 @@ public class Character {
 
   @Override
   public String toString() {
-    var sb = new StringBuilder();
-    sb.append("This is a ")
+    return new StringBuilder()
+        .append("This is a ")
         .append(fighterClass != null ? fighterClass : wizardClass)
         .append(" named ")
         .append(name)
         .append(" armed with a ")
         .append(weapon != null ? weapon : spell != null ? spell : "with nothing")
         .append(abilities != null ? " and wielding " + abilities + " abilities" : "")
-        .append('.');
-    return sb.toString();
+        .append('.')
+        .toString();
   }
 }

step-builder/src/main/java/com/iluwatar/stepbuilder/CharacterStepBuilder.java

@@ -165,7 +165,7 @@ public final class CharacterStepBuilder {
 
     @Override
     public Character build() {
-      Character character = new Character(name);
+      var character = new Character(name);
 
       if (fighterClass != null) {
         character.setFighterClass(fighterClass);

step-builder/src/test/java/com/iluwatar/stepbuilder/AppTest.java

@@ -26,15 +26,12 @@ package com.iluwatar.stepbuilder;
 import org.junit.jupiter.api.Test;
 
 /**
- * 
  * Application test
- *
  */
 public class AppTest {
 
   @Test
   public void test() {
-    String[] args = {};
-    App.main(args);
+    App.main(new String[]{});
   }
 }

step-builder/src/test/java/com/iluwatar/stepbuilder/CharacterStepBuilderTest.java

@@ -23,15 +23,13 @@
 
 package com.iluwatar.stepbuilder;
 
-import org.junit.jupiter.api.Test;
-
-import java.util.List;
-
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
+import org.junit.jupiter.api.Test;
+
 /**
  * Date: 12/29/15 - 9:21 PM
  *
@@ -44,7 +42,7 @@ public class CharacterStepBuilderTest {
    */
   @Test
   public void testBuildWizard() {
-    final Character character = CharacterStepBuilder.newBuilder()
+    final var character = CharacterStepBuilder.newBuilder()
         .name("Merlin")
         .wizardClass("alchemist")
         .withSpell("poison")
@@ -58,7 +56,7 @@ public class CharacterStepBuilderTest {
     assertEquals("poison", character.getSpell());
     assertNotNull(character.toString());
 
-    final List<String> abilities = character.getAbilities();
+    final var abilities = character.getAbilities();
     assertNotNull(abilities);
     assertEquals(2, abilities.size());
     assertTrue(abilities.contains("invisibility"));
@@ -72,7 +70,7 @@ public class CharacterStepBuilderTest {
    */
   @Test
   public void testBuildPoorWizard() {
-    final Character character = CharacterStepBuilder.newBuilder()
+    final var character = CharacterStepBuilder.newBuilder()
         .name("Merlin")
         .wizardClass("alchemist")
         .noSpell()
@@ -91,7 +89,7 @@ public class CharacterStepBuilderTest {
    */
   @Test
   public void testBuildWeakWizard() {
-    final Character character = CharacterStepBuilder.newBuilder()
+    final var character = CharacterStepBuilder.newBuilder()
         .name("Merlin")
         .wizardClass("alchemist")
         .withSpell("poison")
@@ -112,7 +110,7 @@ public class CharacterStepBuilderTest {
    */
   @Test
   public void testBuildWarrior() {
-    final Character character = CharacterStepBuilder.newBuilder()
+    final var character = CharacterStepBuilder.newBuilder()
         .name("Cuauhtemoc")
         .fighterClass("aztec")
         .withWeapon("spear")
@@ -126,7 +124,7 @@ public class CharacterStepBuilderTest {
     assertEquals("spear", character.getWeapon());
     assertNotNull(character.toString());
 
-    final List<String> abilities = character.getAbilities();
+    final var abilities = character.getAbilities();
     assertNotNull(abilities);
     assertEquals(2, abilities.size());
     assertTrue(abilities.contains("speed"));
@@ -140,7 +138,7 @@ public class CharacterStepBuilderTest {
    */
   @Test
   public void testBuildPoorWarrior() {
-    final Character character = CharacterStepBuilder.newBuilder()
+    final var character = CharacterStepBuilder.newBuilder()
         .name("Poor warrior")
         .fighterClass("none")
         .noWeapon()
@@ -160,7 +158,7 @@ public class CharacterStepBuilderTest {
    */
   @Test
   public void testBuildWeakWarrior() {
-    final Character character = CharacterStepBuilder.newBuilder()
+    final var character = CharacterStepBuilder.newBuilder()
         .name("Weak warrior")
         .fighterClass("none")
         .withWeapon("Slingshot")