Java 11 migration: patterns starting with a (#1084)

* Moves abstract-factory pattern to java 11

* Moves abstract-document pattern to java 11

* Moves acyclic-visitor pattern to java 11

* Moves adapter pattern to java 11

* Moves aggregator-microservices pattern to java 11

* Moves api-gateway pattern to java 11

abstract-factory/README.md

@@ -109,10 +109,10 @@ public class OrcKingdomFactory implements KingdomFactory {
 Now we have our abstract factory that lets us make family of related objects i.e. Elven kingdom factory creates Elven castle, king and army etc.
 
 ```java
-KingdomFactory factory = new ElfKingdomFactory();
-Castle castle = factory.createCastle();
-King king = factory.createKing();
-Army army = factory.createArmy();
+var factory = new ElfKingdomFactory();
+var castle = factory.createCastle();
+var king = factory.createKing();
+var army = factory.createArmy();
 
 castle.getDescription();  // Output: This is the Elven castle!
 king.getDescription(); // Output: This is the Elven king!
@@ -143,7 +143,7 @@ public static class FactoryMaker {
 }
 
 public static void main(String[] args) {
-  App app = new App();
+  var app = new App();
 
   LOGGER.info("Elf Kingdom");
   app.createKingdom(FactoryMaker.makeFactory(KingdomType.ELF));

abstract-factory/src/main/java/com/iluwatar/abstractfactory/App.java

@@ -128,7 +128,7 @@ public class App {
    */
   public static void main(String[] args) {
 
-    App app = new App();
+    var app = new App();
 
     LOGGER.info("Elf Kingdom");
     app.createKingdom(FactoryMaker.makeFactory(KingdomType.ELF));

abstract-factory/src/test/java/com/iluwatar/abstractfactory/AbstractFactoryTest.java

@@ -28,7 +28,6 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import com.iluwatar.abstractfactory.App.FactoryMaker;
 import com.iluwatar.abstractfactory.App.FactoryMaker.KingdomType;
-
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
@@ -49,30 +48,30 @@ public class AbstractFactoryTest {
 
   @Test
   public void king() {
-    final King elfKing = app.getKing(elfFactory);
+    final var elfKing = app.getKing(elfFactory);
     assertTrue(elfKing instanceof ElfKing);
     assertEquals(ElfKing.DESCRIPTION, elfKing.getDescription());
-    final King orcKing = app.getKing(orcFactory);
+    final var orcKing = app.getKing(orcFactory);
     assertTrue(orcKing instanceof OrcKing);
     assertEquals(OrcKing.DESCRIPTION, orcKing.getDescription());
   }
 
   @Test
   public void castle() {
-    final Castle elfCastle = app.getCastle(elfFactory);
+    final var elfCastle = app.getCastle(elfFactory);
     assertTrue(elfCastle instanceof ElfCastle);
     assertEquals(ElfCastle.DESCRIPTION, elfCastle.getDescription());
-    final Castle orcCastle = app.getCastle(orcFactory);
+    final var orcCastle = app.getCastle(orcFactory);
     assertTrue(orcCastle instanceof OrcCastle);
     assertEquals(OrcCastle.DESCRIPTION, orcCastle.getDescription());
   }
 
   @Test
   public void army() {
-    final Army elfArmy = app.getArmy(elfFactory);
+    final var elfArmy = app.getArmy(elfFactory);
     assertTrue(elfArmy instanceof ElfArmy);
     assertEquals(ElfArmy.DESCRIPTION, elfArmy.getDescription());
-    final Army orcArmy = app.getArmy(orcFactory);
+    final var orcArmy = app.getArmy(orcFactory);
     assertTrue(orcArmy instanceof OrcArmy);
     assertEquals(OrcArmy.DESCRIPTION, orcArmy.getDescription());
   }
@@ -80,9 +79,9 @@ public class AbstractFactoryTest {
   @Test
   public void createElfKingdom() {
     app.createKingdom(elfFactory);
-    final King king = app.getKing();
-    final Castle castle = app.getCastle();
-    final Army army = app.getArmy();
+    final var king = app.getKing();
+    final var castle = app.getCastle();
+    final var army = app.getArmy();
     assertTrue(king instanceof ElfKing);
     assertEquals(ElfKing.DESCRIPTION, king.getDescription());
     assertTrue(castle instanceof ElfCastle);
@@ -94,9 +93,9 @@ public class AbstractFactoryTest {
   @Test
   public void createOrcKingdom() {
     app.createKingdom(orcFactory);
-    final King king = app.getKing();
-    final Castle castle = app.getCastle();
-    final Army army = app.getArmy();
+    final var king = app.getKing();
+    final var castle = app.getCastle();
+    final var army = app.getArmy();
     assertTrue(king instanceof OrcKing);
     assertEquals(OrcKing.DESCRIPTION, king.getDescription());
     assertTrue(castle instanceof OrcCastle);

abstract-factory/src/test/java/com/iluwatar/abstractfactory/AppTest.java

@@ -25,15 +25,12 @@ package com.iluwatar.abstractfactory;
 
 import org.junit.jupiter.api.Test;
 
-import java.io.IOException;
-
 /**
  * Tests that Abstract Factory example runs without errors.
  */
 public class AppTest {
   @Test
-  public void test() throws IOException {
-    String[] args = {};
-    App.main(args);
+  public void test() {
+    App.main(new String[]{});
   }
 }