Java 11 migrate remaining (g,h,i) (#1116)

* Moves game-loop to Java 11

* Moves guarded-suspension to Java 11

* Moves half-sync-half-async to Java 11

* Moves hexagonal to Java 11

* Moves intercepting-filter to Java 11

* Moves interpreter to Java 11

* Moves iterator to Java 11

game-loop/src/main/java/com/iluwatar/gameloop/GameLoop.java

@@ -70,7 +70,7 @@ public abstract class GameLoop {
    * @return {@code true} if the game is running.
    */
   public boolean isGameRunning() {
-    return status == GameStatus.RUNNING ? true : false;
+    return status == GameStatus.RUNNING;
   }
 
   /**
@@ -80,7 +80,7 @@ public abstract class GameLoop {
    */
   protected void processInput() {
     try {
-      int lag = new Random().nextInt(200) + 50;
+      var lag = new Random().nextInt(200) + 50;
       Thread.sleep(lag);
     } catch (InterruptedException e) {
       logger.error(e.getMessage());

game-loop/src/test/java/com/iluwatar/gameloop/AppTest.java

@@ -32,8 +32,7 @@ public class AppTest {
 
   @Test
   public void testMain() {
-    String[] args = {};
+    new App().main(new String[]{});
-    new App().main(args);
   }
 
 }

game-loop/src/test/java/com/iluwatar/gameloop/GameLoopTest.java

@@ -65,7 +65,7 @@ public class GameLoopTest {
 
   @Test
   public void testIsGameRunning() {
-    Assert.assertEquals(false, gameLoop.isGameRunning());
+    Assert.assertFalse(gameLoop.isGameRunning());
   }
 
 }

guarded-suspension/src/main/java/com/iluwatar/guarded/suspension/App.java

@@ -23,7 +23,6 @@
 
 package com.iluwatar.guarded.suspension;
 
-import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 
@@ -45,14 +44,11 @@ public class App {
    * @param args - command line args
    */
   public static void main(String[] args) {
-    GuardedQueue guardedQueue = new GuardedQueue();
+    var guardedQueue = new GuardedQueue();
-    ExecutorService executorService = Executors.newFixedThreadPool(3);
+    var executorService = Executors.newFixedThreadPool(3);
 
     //here we create first thread which is supposed to get from guardedQueue
-    executorService.execute(() -> {
+    executorService.execute(guardedQueue::get);
-          guardedQueue.get();
-        }
-    );
 
     // here we wait two seconds to show that the thread which is trying
     // to get from guardedQueue will be waiting
@@ -63,10 +59,7 @@ public class App {
     }
     // now we execute second thread which will put number to guardedQueue
     // and notify first thread that it could get
-    executorService.execute(() -> {
+    executorService.execute(() -> guardedQueue.put(20));
-          guardedQueue.put(20);
-        }
-    );
     executorService.shutdown();
     try {
       executorService.awaitTermination(30, TimeUnit.SECONDS);

guarded-suspension/src/test/java/com/iluwatar/guarded/suspension/GuardedQueueTest.java

@@ -23,13 +23,11 @@
 
 package com.iluwatar.guarded.suspension;
 
-import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
-import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
-
+import org.junit.jupiter.api.Test;
-import static org.junit.jupiter.api.Assertions.assertEquals;
 
 /**
  * Test for Guarded Queue
@@ -39,8 +37,8 @@ public class GuardedQueueTest {
 
   @Test
   public void testGet() {
-    GuardedQueue g = new GuardedQueue();
+    var g = new GuardedQueue();
-    ExecutorService executorService = Executors.newFixedThreadPool(2);
+    var executorService = Executors.newFixedThreadPool(2);
     executorService.submit(() -> value = g.get());
     executorService.submit(() -> g.put(10));
     executorService.shutdown();
@@ -54,7 +52,7 @@ public class GuardedQueueTest {
 
   @Test
   public void testPut() {
-    GuardedQueue g = new GuardedQueue();
+    var g = new GuardedQueue();
     g.put(12);
     assertEquals(Integer.valueOf(12), g.get());
   }

half-sync-half-async/src/main/java/com/iluwatar/halfsynchalfasync/App.java

@@ -70,7 +70,7 @@ public class App {
    * @param args command line args
    */
   public static void main(String[] args) {
-    AsynchronousService service = new AsynchronousService(new LinkedBlockingQueue<>());
+    var service = new AsynchronousService(new LinkedBlockingQueue<>());
     /*
      * A new task to calculate sum is received but as this is main thread, it should not block. So
      * it passes it to the asynchronous task layer to compute and proceeds with handling other

half-sync-half-async/src/test/java/com/iluwatar/halfsynchalfasync/AppTest.java

@@ -25,12 +25,8 @@ package com.iluwatar.halfsynchalfasync;
 
 import org.junit.jupiter.api.Test;
 
-import java.util.concurrent.ExecutionException;
-
 /**
- * 
  * Application test
- *
  */
 public class AppTest {
 

half-sync-half-async/src/test/java/com/iluwatar/halfsynchalfasync/AsynchronousServiceTest.java

@@ -57,13 +57,13 @@ public class AsynchronousServiceTest {
 
   @Test
   public void testPerfectExecution() throws Exception {
-    final Object result = new Object();
+    final var result = new Object();
     when(task.call()).thenReturn(result);
     service.execute(task);
 
     verify(task, timeout(2000)).onPostCall(eq(result));
 
-    final InOrder inOrder = inOrder(task);
+    final var inOrder = inOrder(task);
     inOrder.verify(task, times(1)).onPreCall();
     inOrder.verify(task, times(1)).call();
     inOrder.verify(task, times(1)).onPostCall(eq(result));
@@ -73,13 +73,13 @@ public class AsynchronousServiceTest {
 
   @Test
   public void testCallException() throws Exception {
-    final IOException exception = new IOException();
+    final var exception = new IOException();
     when(task.call()).thenThrow(exception);
     service.execute(task);
 
     verify(task, timeout(2000)).onError(eq(exception));
 
-    final InOrder inOrder = inOrder(task);
+    final var inOrder = inOrder(task);
     inOrder.verify(task, times(1)).onPreCall();
     inOrder.verify(task, times(1)).call();
     inOrder.verify(task, times(1)).onError(exception);
@@ -89,13 +89,13 @@ public class AsynchronousServiceTest {
 
   @Test
   public void testPreCallException() {
-    final IllegalStateException exception = new IllegalStateException();
+    final var exception = new IllegalStateException();
     doThrow(exception).when(task).onPreCall();
     service.execute(task);
 
     verify(task, timeout(2000)).onError(eq(exception));
 
-    final InOrder inOrder = inOrder(task);
+    final var inOrder = inOrder(task);
     inOrder.verify(task, times(1)).onPreCall();
     inOrder.verify(task, times(1)).onError(exception);
 

hexagonal/src/main/java/com/iluwatar/hexagonal/App.java

@@ -24,7 +24,6 @@
 package com.iluwatar.hexagonal;
 
 import com.google.inject.Guice;
-import com.google.inject.Injector;
 import com.iluwatar.hexagonal.domain.LotteryAdministration;
 import com.iluwatar.hexagonal.domain.LotteryService;
 import com.iluwatar.hexagonal.module.LotteryTestingModule;
@@ -63,14 +62,14 @@ public class App {
    */
   public static void main(String[] args) {
 
-    Injector injector = Guice.createInjector(new LotteryTestingModule());
+    var injector = Guice.createInjector(new LotteryTestingModule());
 
     // start new lottery round
-    LotteryAdministration administration = injector.getInstance(LotteryAdministration.class);
+    var administration = injector.getInstance(LotteryAdministration.class);
     administration.resetLottery();
 
     // submit some lottery tickets
-    LotteryService service = injector.getInstance(LotteryService.class);
+    var service = injector.getInstance(LotteryService.class);
     SampleData.submitTickets(service, 20);
 
     // perform lottery

hexagonal/src/main/java/com/iluwatar/hexagonal/administration/ConsoleAdministration.java

@@ -24,7 +24,6 @@
 package com.iluwatar.hexagonal.administration;
 
 import com.google.inject.Guice;
-import com.google.inject.Injector;
 import com.iluwatar.hexagonal.domain.LotteryAdministration;
 import com.iluwatar.hexagonal.domain.LotteryService;
 import com.iluwatar.hexagonal.module.LotteryModule;
@@ -46,17 +45,16 @@ public class ConsoleAdministration {
    */
   public static void main(String[] args) {
     MongoConnectionPropertiesLoader.load();
-    Injector injector = Guice.createInjector(new LotteryModule());
+    var injector = Guice.createInjector(new LotteryModule());
-    LotteryAdministration administration = injector.getInstance(LotteryAdministration.class);
+    var administration = injector.getInstance(LotteryAdministration.class);
-    LotteryService service = injector.getInstance(LotteryService.class);
+    var service = injector.getInstance(LotteryService.class);
     SampleData.submitTickets(service, 20);
-    ConsoleAdministrationSrv consoleAdministration =
+    var consoleAdministration = new ConsoleAdministrationSrvImpl(administration, LOGGER);
-        new ConsoleAdministrationSrvImpl(administration, LOGGER);
+    try (var scanner = new Scanner(System.in)) {
-    try (Scanner scanner = new Scanner(System.in)) {
+      var exit = false;
-      boolean exit = false;
       while (!exit) {
         printMainMenu();
-        String cmd = readString(scanner);
+        var cmd = readString(scanner);
         if ("1".equals(cmd)) {
           consoleAdministration.getAllSubmittedTickets();
         } else if ("2".equals(cmd)) {

hexagonal/src/main/java/com/iluwatar/hexagonal/administration/ConsoleAdministrationSrvImpl.java

@@ -50,7 +50,7 @@ public class ConsoleAdministrationSrvImpl implements ConsoleAdministrationSrv {
 
   @Override
   public void performLottery() {
-    LotteryNumbers numbers = administration.performLottery();
+    var numbers = administration.performLottery();
     logger.info("The winning numbers: {}", numbers.getNumbersAsString());
     logger.info("Time to reset the database for next round, eh?");
   }

hexagonal/src/main/java/com/iluwatar/hexagonal/banking/MongoBank.java

@@ -28,7 +28,6 @@ import com.mongodb.client.MongoCollection;
 import com.mongodb.client.MongoDatabase;
 import com.mongodb.client.model.UpdateOptions;
 import java.util.ArrayList;
-import java.util.List;
 import org.bson.Document;
 
 /**
@@ -107,30 +106,31 @@ public class MongoBank implements WireTransfers {
 
   @Override
   public void setFunds(String bankAccount, int amount) {
-    Document search = new Document("_id", bankAccount);
+    var search = new Document("_id", bankAccount);
-    Document update = new Document("_id", bankAccount).append("funds", amount);
+    var update = new Document("_id", bankAccount).append("funds", amount);
-    accountsCollection
+    var updateOptions = new UpdateOptions().upsert(true);
-        .updateOne(search, new Document("$set", update), new UpdateOptions().upsert(true));
+    accountsCollection.updateOne(search, new Document("$set", update), updateOptions);
   }
 
   @Override
   public int getFunds(String bankAccount) {
-    Document search = new Document("_id", bankAccount);
+    return accountsCollection
-    List<Document> results = accountsCollection.find(search).limit(1).into(new ArrayList<>());
+        .find(new Document("_id", bankAccount))
-    if (results.size() > 0) {
+        .limit(1)
-      return results.get(0).getInteger("funds");
+        .into(new ArrayList<>())
-    } else {
+        .stream()
-      return 0;
+        .findFirst()
-    }
+        .map(x -> x.getInteger("funds"))
+        .orElse(0);
   }
 
   @Override
   public boolean transferFunds(int amount, String sourceAccount, String destinationAccount) {
-    int sourceFunds = getFunds(sourceAccount);
+    var sourceFunds = getFunds(sourceAccount);
     if (sourceFunds < amount) {
       return false;
     } else {
-      int destFunds = getFunds(destinationAccount);
+      var destFunds = getFunds(destinationAccount);
       setFunds(sourceAccount, sourceFunds - amount);
       setFunds(destinationAccount, destFunds + amount);
       return true;

hexagonal/src/main/java/com/iluwatar/hexagonal/database/InMemoryTicketRepository.java

@@ -38,17 +38,12 @@ public class InMemoryTicketRepository implements LotteryTicketRepository {
 
   @Override
   public Optional<LotteryTicket> findById(LotteryTicketId id) {
-    LotteryTicket ticket = tickets.get(id);
+    return Optional.ofNullable(tickets.get(id));
-    if (ticket == null) {
-      return Optional.empty();
-    } else {
-      return Optional.of(ticket);
-    }
   }
 
   @Override
   public Optional<LotteryTicketId> save(LotteryTicket ticket) {
-    LotteryTicketId id = new LotteryTicketId();
+    var id = new LotteryTicketId();
     tickets.put(id, ticket);
     return Optional.of(id);
   }

hexagonal/src/main/java/com/iluwatar/hexagonal/database/MongoTicketRepository.java

@@ -32,11 +32,9 @@ import com.mongodb.client.MongoCollection;
 import com.mongodb.client.MongoDatabase;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
 import java.util.Optional;
-import java.util.Set;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import org.bson.Document;
 
@@ -95,7 +93,7 @@ public class MongoTicketRepository implements LotteryTicketRepository {
   }
 
   private void initCounters() {
-    Document doc = new Document("_id", "ticketId").append("seq", 1);
+    var doc = new Document("_id", "ticketId").append("seq", 1);
     countersCollection.insertOne(doc);
   }
 
@@ -105,10 +103,10 @@ public class MongoTicketRepository implements LotteryTicketRepository {
    * @return next ticket id
    */
   public int getNextId() {
-    Document find = new Document("_id", "ticketId");
+    var find = new Document("_id", "ticketId");
-    Document increase = new Document("seq", 1);
+    var increase = new Document("seq", 1);
-    Document update = new Document("$inc", increase);
+    var update = new Document("$inc", increase);
-    Document result = countersCollection.findOneAndUpdate(find, update);
+    var result = countersCollection.findOneAndUpdate(find, update);
     return result.getInteger("seq");
   }
 
@@ -132,20 +130,19 @@ public class MongoTicketRepository implements LotteryTicketRepository {
 
   @Override
   public Optional<LotteryTicket> findById(LotteryTicketId id) {
-    Document find = new Document("ticketId", id.getId());
+    return ticketsCollection
-    List<Document> results = ticketsCollection.find(find).limit(1).into(new ArrayList<>());
+        .find(new Document("ticketId", id.getId()))
-    if (results.size() > 0) {
+        .limit(1)
-      LotteryTicket lotteryTicket = docToTicket(results.get(0));
+        .into(new ArrayList<>())
-      return Optional.of(lotteryTicket);
+        .stream()
-    } else {
+        .findFirst()
-      return Optional.empty();
+        .map(this::docToTicket);
-    }
   }
 
   @Override
   public Optional<LotteryTicketId> save(LotteryTicket ticket) {
-    int ticketId = getNextId();
+    var ticketId = getNextId();
-    Document doc = new Document("ticketId", ticketId);
+    var doc = new Document("ticketId", ticketId);
     doc.put("email", ticket.getPlayerDetails().getEmail());
     doc.put("bank", ticket.getPlayerDetails().getBankAccount());
     doc.put("phone", ticket.getPlayerDetails().getPhoneNumber());
@@ -156,13 +153,12 @@ public class MongoTicketRepository implements LotteryTicketRepository {
 
   @Override
   public Map<LotteryTicketId, LotteryTicket> findAll() {
-    Map<LotteryTicketId, LotteryTicket> map = new HashMap<>();
+    return ticketsCollection
-    List<Document> docs = ticketsCollection.find(new Document()).into(new ArrayList<>());
+        .find(new Document())
-    for (Document doc : docs) {
+        .into(new ArrayList<>())
-      LotteryTicket lotteryTicket = docToTicket(doc);
+        .stream()
-      map.put(lotteryTicket.getId(), lotteryTicket);
+        .map(this::docToTicket)
-    }
+        .collect(Collectors.toMap(LotteryTicket::getId, Function.identity()));
-    return map;
   }
 
   @Override
@@ -171,13 +167,13 @@ public class MongoTicketRepository implements LotteryTicketRepository {
   }
 
   private LotteryTicket docToTicket(Document doc) {
-    PlayerDetails playerDetails = new PlayerDetails(doc.getString("email"), doc.getString("bank"),
+    var playerDetails = new PlayerDetails(doc.getString("email"), doc.getString("bank"),
         doc.getString("phone"));
-    Set<Integer> numbers = Arrays.stream(doc.getString("numbers").split(","))
+    var numbers = Arrays.stream(doc.getString("numbers").split(","))
         .map(Integer::parseInt)
         .collect(Collectors.toSet());
-    LotteryNumbers lotteryNumbers = LotteryNumbers.create(numbers);
+    var lotteryNumbers = LotteryNumbers.create(numbers);
-    return new LotteryTicket(new LotteryTicketId(doc
+    var ticketId = new LotteryTicketId(doc.getInteger("ticketId"));
-        .getInteger("ticketId")), playerDetails, lotteryNumbers);
+    return new LotteryTicket(ticketId, playerDetails, lotteryNumbers);
   }
 }

hexagonal/src/main/java/com/iluwatar/hexagonal/domain/LotteryAdministration.java

@@ -23,6 +23,9 @@
 
 package com.iluwatar.hexagonal.domain;
 
+import static com.iluwatar.hexagonal.domain.LotteryConstants.PRIZE_AMOUNT;
+import static com.iluwatar.hexagonal.domain.LotteryConstants.SERVICE_BANK_ACCOUNT;
+
 import com.google.inject.Inject;
 import com.iluwatar.hexagonal.banking.WireTransfers;
 import com.iluwatar.hexagonal.database.LotteryTicketRepository;
@@ -60,23 +63,21 @@ public class LotteryAdministration {
    * Draw lottery numbers.
    */
   public LotteryNumbers performLottery() {
-    LotteryNumbers numbers = LotteryNumbers.createRandom();
+    var numbers = LotteryNumbers.createRandom();
-    Map<LotteryTicketId, LotteryTicket> tickets = getAllSubmittedTickets();
+    var tickets = getAllSubmittedTickets();
-    for (LotteryTicketId id : tickets.keySet()) {
+    for (var id : tickets.keySet()) {
-      LotteryTicketCheckResult result = LotteryUtils.checkTicketForPrize(repository, id, numbers);
+      var lotteryTicket = tickets.get(id);
-      if (result.getResult().equals(LotteryTicketCheckResult.CheckResult.WIN_PRIZE)) {
+      var playerDetails = lotteryTicket.getPlayerDetails();
-        boolean transferred = wireTransfers.transferFunds(LotteryConstants.PRIZE_AMOUNT,
+      var playerAccount = playerDetails.getBankAccount();
-            LotteryConstants.SERVICE_BANK_ACCOUNT, tickets.get(id).getPlayerDetails()
+      var result = LotteryUtils.checkTicketForPrize(repository, id, numbers).getResult();
-                .getBankAccount());
+      if (result == LotteryTicketCheckResult.CheckResult.WIN_PRIZE) {
-        if (transferred) {
+        if (wireTransfers.transferFunds(PRIZE_AMOUNT, SERVICE_BANK_ACCOUNT, playerAccount)) {
-          notifications
+          notifications.ticketWon(playerDetails, PRIZE_AMOUNT);
-              .ticketWon(tickets.get(id).getPlayerDetails(), LotteryConstants.PRIZE_AMOUNT);
         } else {
-          notifications
+          notifications.prizeError(playerDetails, PRIZE_AMOUNT);
-              .prizeError(tickets.get(id).getPlayerDetails(), LotteryConstants.PRIZE_AMOUNT);
         }
-      } else if (result.getResult().equals(LotteryTicketCheckResult.CheckResult.NO_PRIZE)) {
+      } else if (result == LotteryTicketCheckResult.CheckResult.NO_PRIZE) {
-        notifications.ticketDidNotWin(tickets.get(id).getPlayerDetails());
+        notifications.ticketDidNotWin(playerDetails);
       }
     }
     return numbers;

hexagonal/src/main/java/com/iluwatar/hexagonal/domain/LotteryNumbers.java

@@ -99,9 +99,9 @@ public class LotteryNumbers {
    */
   private void generateRandomNumbers() {
     numbers.clear();
-    RandomNumberGenerator generator = new RandomNumberGenerator(MIN_NUMBER, MAX_NUMBER);
+    var generator = new RandomNumberGenerator(MIN_NUMBER, MAX_NUMBER);
     while (numbers.size() < NUM_NUMBERS) {
-      int num = generator.nextInt();
+      var num = generator.nextInt();
       numbers.add(num);
     }
   }
@@ -141,8 +141,8 @@ public class LotteryNumbers {
 
   @Override
   public int hashCode() {
-    final int prime = 31;
+    final var prime = 31;
-    int result = 1;
+    var result = 1;
     result = prime * result + ((numbers == null) ? 0 : numbers.hashCode());
     return result;
   }
@@ -158,14 +158,11 @@ public class LotteryNumbers {
     if (getClass() != obj.getClass()) {
       return false;
     }
-    LotteryNumbers other = (LotteryNumbers) obj;
+    var other = (LotteryNumbers) obj;
     if (numbers == null) {
-      if (other.numbers != null) {
+      return other.numbers == null;
-        return false;
+    } else {
-      }
+      return numbers.equals(other.numbers);
-    } else if (!numbers.equals(other.numbers)) {
-      return false;
     }
-    return true;
   }
 }

hexagonal/src/main/java/com/iluwatar/hexagonal/domain/LotteryService.java

@@ -23,6 +23,9 @@
 
 package com.iluwatar.hexagonal.domain;
 
+import static com.iluwatar.hexagonal.domain.LotteryConstants.SERVICE_BANK_ACCOUNT;
+import static com.iluwatar.hexagonal.domain.LotteryConstants.TICKET_PRIZE;
+
 import com.google.inject.Inject;
 import com.iluwatar.hexagonal.banking.WireTransfers;
 import com.iluwatar.hexagonal.database.LotteryTicketRepository;
@@ -53,15 +56,16 @@ public class LotteryService {
    * Submit lottery ticket to participate in the lottery.
    */
   public Optional<LotteryTicketId> submitTicket(LotteryTicket ticket) {
-    boolean result = wireTransfers.transferFunds(LotteryConstants.TICKET_PRIZE,
+    var playerDetails = ticket.getPlayerDetails();
-        ticket.getPlayerDetails().getBankAccount(), LotteryConstants.SERVICE_BANK_ACCOUNT);
+    var playerAccount = playerDetails.getBankAccount();
+    var result = wireTransfers.transferFunds(TICKET_PRIZE, playerAccount, SERVICE_BANK_ACCOUNT);
     if (!result) {
-      notifications.ticketSubmitError(ticket.getPlayerDetails());
+      notifications.ticketSubmitError(playerDetails);
       return Optional.empty();
     }
-    Optional<LotteryTicketId> optional = repository.save(ticket);
+    var optional = repository.save(ticket);
     if (optional.isPresent()) {
-      notifications.ticketSubmitted(ticket.getPlayerDetails());
+      notifications.ticketSubmitted(playerDetails);
     }
     return optional;
   }

hexagonal/src/main/java/com/iluwatar/hexagonal/domain/LotteryTicket.java

@@ -82,8 +82,8 @@ public class LotteryTicket {
 
   @Override
   public int hashCode() {
-    final int prime = 31;
+    final var prime = 31;
-    int result = 1;
+    var result = 1;
     result = prime * result + ((lotteryNumbers == null) ? 0 : lotteryNumbers.hashCode());
     result = prime * result + ((playerDetails == null) ? 0 : playerDetails.hashCode());
     return result;
@@ -100,7 +100,7 @@ public class LotteryTicket {
     if (getClass() != obj.getClass()) {
       return false;
     }
-    LotteryTicket other = (LotteryTicket) obj;
+    var other = (LotteryTicket) obj;
     if (lotteryNumbers == null) {
       if (other.lotteryNumbers != null) {
         return false;
@@ -109,12 +109,9 @@ public class LotteryTicket {
       return false;
     }
     if (playerDetails == null) {
-      if (other.playerDetails != null) {
+      return other.playerDetails == null;
-        return false;
+    } else {
-      }
+      return playerDetails.equals(other.playerDetails);
-    } else if (!playerDetails.equals(other.playerDetails)) {
-      return false;
     }
-    return true;
   }
 }

hexagonal/src/main/java/com/iluwatar/hexagonal/domain/LotteryTicketCheckResult.java

@@ -76,8 +76,8 @@ public class LotteryTicketCheckResult {
 
   @Override
   public int hashCode() {
-    final int prime = 31;
+    final var prime = 31;
-    int result = 1;
+    var result = 1;
     result = prime * result + ((checkResult == null) ? 0 : checkResult.hashCode());
     result = prime * result + prizeAmount;
     return result;
@@ -94,7 +94,7 @@ public class LotteryTicketCheckResult {
     if (getClass() != obj.getClass()) {
       return false;
     }
-    LotteryTicketCheckResult other = (LotteryTicketCheckResult) obj;
+    var other = (LotteryTicketCheckResult) obj;
     return checkResult == other.checkResult && prizeAmount == other.prizeAmount;
   }
 }

hexagonal/src/main/java/com/iluwatar/hexagonal/domain/LotteryTicketId.java

@@ -59,10 +59,9 @@ public class LotteryTicketId {
       return false;
     }
 
-    LotteryTicketId that = (LotteryTicketId) o;
+    var that = (LotteryTicketId) o;
 
     return id == that.id;
-
   }
 
   @Override

hexagonal/src/main/java/com/iluwatar/hexagonal/domain/LotteryUtils.java

@@ -25,7 +25,6 @@ package com.iluwatar.hexagonal.domain;
 
 import com.iluwatar.hexagonal.database.LotteryTicketRepository;
 import com.iluwatar.hexagonal.domain.LotteryTicketCheckResult.CheckResult;
-import java.util.Optional;
 
 /**
  * Lottery utilities.
@@ -43,7 +42,7 @@ public class LotteryUtils {
       LotteryTicketId id,
       LotteryNumbers winningNumbers
   ) {
-    Optional<LotteryTicket> optional = repository.findById(id);
+    var optional = repository.findById(id);
     if (optional.isPresent()) {
       if (optional.get().getNumbers().equals(winningNumbers)) {
         return new LotteryTicketCheckResult(CheckResult.WIN_PRIZE, 1000);

hexagonal/src/main/java/com/iluwatar/hexagonal/domain/PlayerDetails.java

@@ -77,8 +77,8 @@ public class PlayerDetails {
 
   @Override
   public int hashCode() {
-    final int prime = 31;
+    final var prime = 31;
-    int result = 1;
+    var result = 1;
     result = prime * result + ((bankAccountNumber == null) ? 0 : bankAccountNumber.hashCode());
     result = prime * result + ((emailAddress == null) ? 0 : emailAddress.hashCode());
     result = prime * result + ((phoneNumber == null) ? 0 : phoneNumber.hashCode());
@@ -96,7 +96,7 @@ public class PlayerDetails {
     if (getClass() != obj.getClass()) {
       return false;
     }
-    PlayerDetails other = (PlayerDetails) obj;
+    var other = (PlayerDetails) obj;
     if (bankAccountNumber == null) {
       if (other.bankAccountNumber != null) {
         return false;
@@ -112,12 +112,9 @@ public class PlayerDetails {
       return false;
     }
     if (phoneNumber == null) {
-      if (other.phoneNumber != null) {
+      return other.phoneNumber == null;
-        return false;
+    } else {
-      }
+      return phoneNumber.equals(other.phoneNumber);
-    } else if (!phoneNumber.equals(other.phoneNumber)) {
-      return false;
     }
-    return true;
   }
 }

hexagonal/src/main/java/com/iluwatar/hexagonal/eventlog/MongoEventLog.java

@@ -107,7 +107,7 @@ public class MongoEventLog implements LotteryEventLog {
 
   @Override
   public void ticketSubmitted(PlayerDetails details) {
-    Document document = new Document("email", details.getEmail());
+    var document = new Document("email", details.getEmail());
     document.put("phone", details.getPhoneNumber());
     document.put("bank", details.getBankAccount());
     document
@@ -118,7 +118,7 @@ public class MongoEventLog implements LotteryEventLog {
 
   @Override
   public void ticketSubmitError(PlayerDetails details) {
-    Document document = new Document("email", details.getEmail());
+    var document = new Document("email", details.getEmail());
     document.put("phone", details.getPhoneNumber());
     document.put("bank", details.getBankAccount());
     document.put("message", "Lottery ticket could not be submitted because lack of funds.");
@@ -128,7 +128,7 @@ public class MongoEventLog implements LotteryEventLog {
 
   @Override
   public void ticketDidNotWin(PlayerDetails details) {
-    Document document = new Document("email", details.getEmail());
+    var document = new Document("email", details.getEmail());
     document.put("phone", details.getPhoneNumber());
     document.put("bank", details.getBankAccount());
     document.put("message", "Lottery ticket was checked and unfortunately did not win this time.");
@@ -138,7 +138,7 @@ public class MongoEventLog implements LotteryEventLog {
 
   @Override
   public void ticketWon(PlayerDetails details, int prizeAmount) {
-    Document document = new Document("email", details.getEmail());
+    var document = new Document("email", details.getEmail());
     document.put("phone", details.getPhoneNumber());
     document.put("bank", details.getBankAccount());
     document.put("message", String
@@ -150,7 +150,7 @@ public class MongoEventLog implements LotteryEventLog {
 
   @Override
   public void prizeError(PlayerDetails details, int prizeAmount) {
-    Document document = new Document("email", details.getEmail());
+    var document = new Document("email", details.getEmail());
     document.put("phone", details.getPhoneNumber());
     document.put("bank", details.getBankAccount());
     document.put("message", String

hexagonal/src/main/java/com/iluwatar/hexagonal/eventlog/StdOutEventLog.java

@@ -42,9 +42,8 @@ public class StdOutEventLog implements LotteryEventLog {
 
   @Override
   public void ticketDidNotWin(PlayerDetails details) {
-    LOGGER
+    LOGGER.info("Lottery ticket for {} was checked and unfortunately did not win this time.",
-        .info("Lottery ticket for {} was checked and unfortunately did not win this time.", details
+        details.getEmail());
-            .getEmail());
   }
 
   @Override
@@ -55,9 +54,8 @@ public class StdOutEventLog implements LotteryEventLog {
 
   @Override
   public void prizeError(PlayerDetails details, int prizeAmount) {
-    LOGGER
+    LOGGER.error("Lottery ticket for {} has won! Unfortunately the bank credit transfer of"
-        .error("Lottery ticket for {} has won! Unfortunately the bank credit transfer of"
+        + " {} failed.", details.getEmail(), prizeAmount);
-            + " {} failed.", details.getEmail(), prizeAmount);
   }
 
   @Override

hexagonal/src/main/java/com/iluwatar/hexagonal/mongo/MongoConnectionPropertiesLoader.java

@@ -38,12 +38,12 @@ public class MongoConnectionPropertiesLoader {
    * Try to load connection properties from file. Fall back to default connection properties.
    */
   public static void load() {
-    String host = DEFAULT_HOST;
+    var host = DEFAULT_HOST;
-    int port = DEFAULT_PORT;
+    var port = DEFAULT_PORT;
-    String path = System.getProperty("hexagonal.properties.path");
+    var path = System.getProperty("hexagonal.properties.path");
-    Properties properties = new Properties();
+    var properties = new Properties();
     if (path != null) {
-      try (FileInputStream fin = new FileInputStream(path)) {
+      try (var fin = new FileInputStream(path)) {
         properties.load(fin);
         host = properties.getProperty("mongo-host");
         port = Integer.parseInt(properties.getProperty("mongo-port"));

hexagonal/src/main/java/com/iluwatar/hexagonal/sampledata/SampleData.java

@@ -30,8 +30,10 @@ import com.iluwatar.hexagonal.domain.LotteryService;
 import com.iluwatar.hexagonal.domain.LotteryTicket;
 import com.iluwatar.hexagonal.domain.LotteryTicketId;
 import com.iluwatar.hexagonal.domain.PlayerDetails;
+import java.util.AbstractMap.SimpleEntry;
 import java.util.List;
 import java.util.Random;
+import java.util.stream.Collectors;
 
 /**
  * Utilities for creating sample lottery tickets.
@@ -83,26 +85,28 @@ public class SampleData {
         new PlayerDetails("xavier@google.com", "143-947", "+375245"),
         new PlayerDetails("harriet@google.com", "842-404", "+131243252")
     );
-    InMemoryBank wireTransfers = new InMemoryBank();
+    var wireTransfers = new InMemoryBank();
-    for (PlayerDetails player : PLAYERS) {
+    PLAYERS.stream()
-      wireTransfers.setFunds(player.getBankAccount(),
+        .map(PlayerDetails::getBankAccount)
-          RANDOM.nextInt(LotteryConstants.PLAYER_MAX_BALANCE));
+        .map(e -> new SimpleEntry<>(e, RANDOM.nextInt(LotteryConstants.PLAYER_MAX_BALANCE)))
-    }
+        .collect(Collectors.toMap(SimpleEntry::getKey, SimpleEntry::getValue))
+        .forEach(wireTransfers::setFunds);
   }
 
   /**
    * Inserts lottery tickets into the database based on the sample data.
    */
   public static void submitTickets(LotteryService lotteryService, int numTickets) {
-    for (int i = 0; i < numTickets; i++) {
+    for (var i = 0; i < numTickets; i++) {
-      LotteryTicket ticket = new LotteryTicket(new LotteryTicketId(),
+      var randomPlayerDetails = getRandomPlayerDetails();
-          getRandomPlayerDetails(), LotteryNumbers.createRandom());
+      var lotteryNumbers = LotteryNumbers.createRandom();
+      var lotteryTicketId = new LotteryTicketId();
+      var ticket = new LotteryTicket(lotteryTicketId, randomPlayerDetails, lotteryNumbers);
       lotteryService.submitTicket(ticket);
     }
   }
 
   private static PlayerDetails getRandomPlayerDetails() {
-    int idx = RANDOM.nextInt(PLAYERS.size());
+    return PLAYERS.get(RANDOM.nextInt(PLAYERS.size()));
-    return PLAYERS.get(idx);
   }
 }

hexagonal/src/main/java/com/iluwatar/hexagonal/service/ConsoleLottery.java

@@ -24,7 +24,6 @@
 package com.iluwatar.hexagonal.service;
 
 import com.google.inject.Guice;
-import com.google.inject.Injector;
 import com.iluwatar.hexagonal.banking.WireTransfers;
 import com.iluwatar.hexagonal.domain.LotteryService;
 import com.iluwatar.hexagonal.module.LotteryModule;
@@ -45,15 +44,15 @@ public class ConsoleLottery {
    */
   public static void main(String[] args) {
     MongoConnectionPropertiesLoader.load();
-    Injector injector = Guice.createInjector(new LotteryModule());
+    var injector = Guice.createInjector(new LotteryModule());
-    LotteryService service = injector.getInstance(LotteryService.class);
+    var service = injector.getInstance(LotteryService.class);
-    WireTransfers bank = injector.getInstance(WireTransfers.class);
+    var bank = injector.getInstance(WireTransfers.class);
     try (Scanner scanner = new Scanner(System.in)) {
-      boolean exit = false;
+      var exit = false;
       while (!exit) {
         printMainMenu();
-        String cmd = readString(scanner);
+        var cmd = readString(scanner);
-        LotteryConsoleService lotteryConsoleService = new LotteryConsoleServiceImpl(LOGGER);
+        var lotteryConsoleService = new LotteryConsoleServiceImpl(LOGGER);
         if ("1".equals(cmd)) {
           lotteryConsoleService.queryLotteryAccountFunds(bank, scanner);
         } else if ("2".equals(cmd)) {

hexagonal/src/main/java/com/iluwatar/hexagonal/service/LotteryConsoleServiceImpl.java

@@ -31,10 +31,7 @@ import com.iluwatar.hexagonal.domain.LotteryTicketCheckResult;
 import com.iluwatar.hexagonal.domain.LotteryTicketId;
 import com.iluwatar.hexagonal.domain.PlayerDetails;
 import java.util.Arrays;
-import java.util.HashSet;
-import java.util.Optional;
 import java.util.Scanner;
-import java.util.Set;
 import java.util.stream.Collectors;
 import org.slf4j.Logger;
 
@@ -55,20 +52,18 @@ public class LotteryConsoleServiceImpl implements LotteryConsoleService {
   @Override
   public void checkTicket(LotteryService service, Scanner scanner) {
     logger.info("What is the ID of the lottery ticket?");
-    String id = readString(scanner);
+    var id = readString(scanner);
     logger.info("Give the 4 comma separated winning numbers?");
-    String numbers = readString(scanner);
+    var numbers = readString(scanner);
     try {
-      String[] parts = numbers.split(",");
+      var winningNumbers = Arrays.stream(numbers.split(","))
-      Set<Integer> winningNumbers = new HashSet<>();
+          .map(Integer::parseInt)
-      for (int i = 0; i < 4; i++) {
+          .limit(4)
-        winningNumbers.add(Integer.parseInt(parts[i]));
+          .collect(Collectors.toSet());
-      }
 
-      final LotteryTicketId lotteryTicketId = new LotteryTicketId(Integer.parseInt(id));
+      final var lotteryTicketId = new LotteryTicketId(Integer.parseInt(id));
-      final LotteryNumbers lotteryNumbers = LotteryNumbers.create(winningNumbers);
+      final var lotteryNumbers = LotteryNumbers.create(winningNumbers);
-      LotteryTicketCheckResult result =
+      var result = service.checkTicketForPrize(lotteryTicketId, lotteryNumbers);
-          service.checkTicketForPrize(lotteryTicketId, lotteryNumbers);
 
       if (result.getResult().equals(LotteryTicketCheckResult.CheckResult.WIN_PRIZE)) {
         logger.info("Congratulations! The lottery ticket has won!");
@@ -85,26 +80,24 @@ public class LotteryConsoleServiceImpl implements LotteryConsoleService {
   @Override
   public void submitTicket(LotteryService service, Scanner scanner) {
     logger.info("What is your email address?");
-    String email = readString(scanner);
+    var email = readString(scanner);
     logger.info("What is your bank account number?");
-    String account = readString(scanner);
+    var account = readString(scanner);
     logger.info("What is your phone number?");
-    String phone = readString(scanner);
+    var phone = readString(scanner);
-    PlayerDetails details = new PlayerDetails(email, account, phone);
+    var details = new PlayerDetails(email, account, phone);
     logger.info("Give 4 comma separated lottery numbers?");
-    String numbers = readString(scanner);
+    var numbers = readString(scanner);
     try {
-      String[] parts = numbers.split(",");
+      var chosen = Arrays.stream(numbers.split(","))
-      Set<Integer> chosen = Arrays.stream(parts).map(Integer::parseInt).collect(Collectors.toSet());
+          .map(Integer::parseInt)
-      LotteryNumbers lotteryNumbers = LotteryNumbers.create(chosen);
+          .collect(Collectors.toSet());
-      LotteryTicket lotteryTicket =
+      var lotteryNumbers = LotteryNumbers.create(chosen);
-          new LotteryTicket(new LotteryTicketId(), details, lotteryNumbers);
+      var lotteryTicket = new LotteryTicket(new LotteryTicketId(), details, lotteryNumbers);
-      Optional<LotteryTicketId> id = service.submitTicket(lotteryTicket);
+      service.submitTicket(lotteryTicket).ifPresentOrElse(
-      if (id.isPresent()) {
+          (id) -> logger.info("Submitted lottery ticket with id: {}", id),
-        logger.info("Submitted lottery ticket with id: {}", id.get());
+          () -> logger.info("Failed submitting lottery ticket - please try again.")
-      } else {
+      );
-        logger.info("Failed submitting lottery ticket - please try again.");
-      }
     } catch (Exception e) {
       logger.info("Failed submitting lottery ticket - please try again.");
     }
@@ -113,9 +106,9 @@ public class LotteryConsoleServiceImpl implements LotteryConsoleService {
   @Override
   public void addFundsToLotteryAccount(WireTransfers bank, Scanner scanner) {
     logger.info("What is the account number?");
-    String account = readString(scanner);
+    var account = readString(scanner);
     logger.info("How many credits do you want to deposit?");
-    String amount = readString(scanner);
+    var amount = readString(scanner);
     bank.setFunds(account, Integer.parseInt(amount));
     logger.info("The account {} now has {} credits.", account, bank.getFunds(account));
   }
@@ -123,7 +116,7 @@ public class LotteryConsoleServiceImpl implements LotteryConsoleService {
   @Override
   public void queryLotteryAccountFunds(WireTransfers bank, Scanner scanner) {
     logger.info("What is the account number?");
-    String account = readString(scanner);
+    var account = readString(scanner);
     logger.info("The account {} has {} credits.", account, bank.getFunds(account));
   }
 

hexagonal/src/test/java/com/iluwatar/hexagonal/AppTest.java

@@ -32,7 +32,6 @@ class AppTest {
 
   @Test
   void testApp() {
-    String[] args = {};
+    App.main(new String[]{});
-    App.main(args);
   }
 }

hexagonal/src/test/java/com/iluwatar/hexagonal/banking/InMemoryBankTest.java

@@ -23,20 +23,18 @@
 
 package com.iluwatar.hexagonal.banking;
 
-import org.junit.jupiter.api.Test;
-
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
+import org.junit.jupiter.api.Test;
+
 /**
- * 
  * Tests for banking
- *
  */
 class InMemoryBankTest {
 
   private final WireTransfers bank = new InMemoryBank();
-  
+
   @Test
   void testInit() {
     assertEquals(0, bank.getFunds("foo"));

hexagonal/src/test/java/com/iluwatar/hexagonal/banking/MongoBankTest.java

@@ -23,14 +23,14 @@
 
 package com.iluwatar.hexagonal.banking;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 import com.iluwatar.hexagonal.mongo.MongoConnectionPropertiesLoader;
 import com.mongodb.MongoClient;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
 /**
  * Tests for Mongo banking adapter
  */
@@ -45,7 +45,7 @@ class MongoBankTest {
   @BeforeEach
   void init() {
     MongoConnectionPropertiesLoader.load();
-    MongoClient mongoClient = new MongoClient(System.getProperty("mongo-host"),
+    var mongoClient = new MongoClient(System.getProperty("mongo-host"),
         Integer.parseInt(System.getProperty("mongo-port")));
     mongoClient.dropDatabase(TEST_DB);
     mongoClient.close();

hexagonal/src/test/java/com/iluwatar/hexagonal/database/InMemoryTicketRepositoryTest.java

@@ -23,40 +23,34 @@
 
 package com.iluwatar.hexagonal.database;
 
-import java.util.Optional;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
-import com.iluwatar.hexagonal.domain.LotteryTicket;
-import com.iluwatar.hexagonal.domain.LotteryTicketId;
 import com.iluwatar.hexagonal.test.LotteryTestUtils;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
 /**
- * 
  * Tests for {@link LotteryTicketRepository}
- *
  */
 class InMemoryTicketRepositoryTest {
 
   private final LotteryTicketRepository repository = new InMemoryTicketRepository();
-  
+
   @BeforeEach
   void clear() {
     repository.deleteAll();
   }
-  
+
   @Test
   void testCrudOperations() {
-    LotteryTicketRepository repository = new InMemoryTicketRepository();
+    var repository = new InMemoryTicketRepository();
     assertTrue(repository.findAll().isEmpty());
-    LotteryTicket ticket = LotteryTestUtils.createLotteryTicket();
+    var ticket = LotteryTestUtils.createLotteryTicket();
-    Optional<LotteryTicketId> id = repository.save(ticket);
+    var id = repository.save(ticket);
     assertTrue(id.isPresent());
     assertEquals(1, repository.findAll().size());
-    Optional<LotteryTicket> optionalTicket = repository.findById(id.get());
+    var optionalTicket = repository.findById(id.get());
     assertTrue(optionalTicket.isPresent());
   }
 }

hexagonal/src/test/java/com/iluwatar/hexagonal/database/MongoTicketRepositoryTest.java

@@ -23,6 +23,9 @@
 
 package com.iluwatar.hexagonal.database;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
 import com.iluwatar.hexagonal.domain.LotteryNumbers;
 import com.iluwatar.hexagonal.domain.LotteryTicket;
 import com.iluwatar.hexagonal.domain.LotteryTicketId;
@@ -33,11 +36,6 @@ import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 
-import java.util.Optional;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
 /**
  * Tests for Mongo based ticket repository
  */
@@ -53,7 +51,7 @@ class MongoTicketRepositoryTest {
   @BeforeEach
   void init() {
     MongoConnectionPropertiesLoader.load();
-    MongoClient mongoClient = new MongoClient(System.getProperty("mongo-host"),
+    var mongoClient = new MongoClient(System.getProperty("mongo-host"),
         Integer.parseInt(System.getProperty("mongo-port")));
     mongoClient.dropDatabase(TEST_DB);
     mongoClient.close();
@@ -77,16 +75,16 @@ class MongoTicketRepositoryTest {
   @Test
   void testCrudOperations() {
     // create new lottery ticket and save it
-    PlayerDetails details = new PlayerDetails("foo@bar.com", "123-123", "07001234");
+    var details = new PlayerDetails("foo@bar.com", "123-123", "07001234");
-    LotteryNumbers random = LotteryNumbers.createRandom();
+    var random = LotteryNumbers.createRandom();
-    LotteryTicket original = new LotteryTicket(new LotteryTicketId(), details, random);
+    var original = new LotteryTicket(new LotteryTicketId(), details, random);
-    Optional<LotteryTicketId> saved = repository.save(original);
+    var saved = repository.save(original);
     assertEquals(1, repository.getTicketsCollection().count());
     assertTrue(saved.isPresent());
     // fetch the saved lottery ticket from database and check its contents
-    Optional<LotteryTicket> found = repository.findById(saved.get());
+    var found = repository.findById(saved.get());
     assertTrue(found.isPresent());
-    LotteryTicket ticket = found.get();
+    var ticket = found.get();
     assertEquals("foo@bar.com", ticket.getPlayerDetails().getEmail());
     assertEquals("123-123", ticket.getPlayerDetails().getBankAccount());
     assertEquals("07001234", ticket.getPlayerDetails().getPhoneNumber());

hexagonal/src/test/java/com/iluwatar/hexagonal/domain/LotteryNumbersTest.java

@@ -23,47 +23,47 @@
 
 package com.iluwatar.hexagonal.domain;
 
-import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.util.Set;
-
+import org.junit.jupiter.api.Test;
-import static org.junit.jupiter.api.Assertions.*;
 
 /**
- * 
  * Unit tests for {@link LotteryNumbers}
- *
  */
 class LotteryNumbersTest {
-  
+
   @Test
   void testGivenNumbers() {
-    LotteryNumbers numbers = LotteryNumbers.create(Set.of(1, 2, 3, 4));
+    var numbers = LotteryNumbers.create(Set.of(1, 2, 3, 4));
     assertEquals(numbers.getNumbers().size(), 4);
     assertTrue(numbers.getNumbers().contains(1));
     assertTrue(numbers.getNumbers().contains(2));
     assertTrue(numbers.getNumbers().contains(3));
     assertTrue(numbers.getNumbers().contains(4));
   }
-  
+
   @Test
   void testNumbersCantBeModified() {
-    LotteryNumbers numbers = LotteryNumbers.create(Set.of(1, 2, 3, 4));
+    var numbers = LotteryNumbers.create(Set.of(1, 2, 3, 4));
     assertThrows(UnsupportedOperationException.class, () -> numbers.getNumbers().add(5));
   }
-  
+
   @Test
   void testRandomNumbers() {
-    LotteryNumbers numbers = LotteryNumbers.createRandom();
+    var numbers = LotteryNumbers.createRandom();
     assertEquals(numbers.getNumbers().size(), LotteryNumbers.NUM_NUMBERS);
   }
-  
+
   @Test
   void testEquals() {
-    LotteryNumbers numbers1 = LotteryNumbers.create(Set.of(1, 2, 3, 4));
+    var numbers1 = LotteryNumbers.create(Set.of(1, 2, 3, 4));
-    LotteryNumbers numbers2 = LotteryNumbers.create(Set.of(1, 2, 3, 4));
+    var numbers2 = LotteryNumbers.create(Set.of(1, 2, 3, 4));
     assertEquals(numbers1, numbers2);
-    LotteryNumbers numbers3 = LotteryNumbers.create(Set.of(11, 12, 13, 14));
+    var numbers3 = LotteryNumbers.create(Set.of(11, 12, 13, 14));
     assertNotEquals(numbers1, numbers3);
   }
 }

hexagonal/src/test/java/com/iluwatar/hexagonal/domain/LotteryTest.java

@@ -23,6 +23,10 @@
 
 package com.iluwatar.hexagonal.domain;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
 import com.google.inject.Guice;
 import com.google.inject.Inject;
 import com.google.inject.Injector;
@@ -30,17 +34,12 @@ import com.iluwatar.hexagonal.banking.WireTransfers;
 import com.iluwatar.hexagonal.domain.LotteryTicketCheckResult.CheckResult;
 import com.iluwatar.hexagonal.module.LotteryTestingModule;
 import com.iluwatar.hexagonal.test.LotteryTestUtils;
+import java.util.Set;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
-import java.util.*;
-
-import static org.junit.jupiter.api.Assertions.*;
-
 /**
- * 
  * Test the lottery system
- *
  */
 class LotteryTest {
 
@@ -62,38 +61,38 @@ class LotteryTest {
     // add funds to the test player's bank account
     wireTransfers.setFunds("123-12312", 100);
   }
-  
+
   @Test
   void testLottery() {
     // admin resets the lottery
     administration.resetLottery();
     assertEquals(0, administration.getAllSubmittedTickets().size());
-    
+
     // players submit the lottery tickets
-    Optional<LotteryTicketId> ticket1 = service.submitTicket(LotteryTestUtils.createLotteryTicket("cvt@bbb.com",
+    var ticket1 = service.submitTicket(LotteryTestUtils.createLotteryTicket("cvt@bbb.com",
         "123-12312", "+32425255", Set.of(1, 2, 3, 4)));
     assertTrue(ticket1.isPresent());
-    Optional<LotteryTicketId> ticket2 = service.submitTicket(LotteryTestUtils.createLotteryTicket("ant@bac.com",
+    var ticket2 = service.submitTicket(LotteryTestUtils.createLotteryTicket("ant@bac.com",
         "123-12312", "+32423455", Set.of(11, 12, 13, 14)));
     assertTrue(ticket2.isPresent());
-    Optional<LotteryTicketId> ticket3 = service.submitTicket(LotteryTestUtils.createLotteryTicket("arg@boo.com",
+    var ticket3 = service.submitTicket(LotteryTestUtils.createLotteryTicket("arg@boo.com",
         "123-12312", "+32421255", Set.of(6, 8, 13, 19)));
     assertTrue(ticket3.isPresent());
     assertEquals(3, administration.getAllSubmittedTickets().size());
-    
+
     // perform lottery
-    LotteryNumbers winningNumbers = administration.performLottery();
+    var winningNumbers = administration.performLottery();
 
     // cheat a bit for testing sake, use winning numbers to submit another ticket
-    Optional<LotteryTicketId> ticket4 = service.submitTicket(LotteryTestUtils.createLotteryTicket("lucky@orb.com",
+    var ticket4 = service.submitTicket(LotteryTestUtils.createLotteryTicket("lucky@orb.com",
         "123-12312", "+12421255", winningNumbers.getNumbers()));
     assertTrue(ticket4.isPresent());
     assertEquals(4, administration.getAllSubmittedTickets().size());
-    
+
     // check winners
-    Map<LotteryTicketId, LotteryTicket> tickets = administration.getAllSubmittedTickets();
+    var tickets = administration.getAllSubmittedTickets();
-    for (LotteryTicketId id: tickets.keySet()) {
+    for (var id : tickets.keySet()) {
-      LotteryTicketCheckResult checkResult = service.checkTicketForPrize(id, winningNumbers);
+      var checkResult = service.checkTicketForPrize(id, winningNumbers);
       assertNotEquals(CheckResult.TICKET_NOT_SUBMITTED, checkResult.getResult());
       if (checkResult.getResult().equals(CheckResult.WIN_PRIZE)) {
         assertTrue(checkResult.getPrizeAmount() > 0);
@@ -101,9 +100,9 @@ class LotteryTest {
         assertEquals(0, checkResult.getPrizeAmount());
       }
     }
-    
+
     // check another ticket that has not been submitted
-    LotteryTicketCheckResult checkResult = service.checkTicketForPrize(new LotteryTicketId(), winningNumbers);
+    var checkResult = service.checkTicketForPrize(new LotteryTicketId(), winningNumbers);
     assertEquals(CheckResult.TICKET_NOT_SUBMITTED, checkResult.getResult());
     assertEquals(0, checkResult.getPrizeAmount());
   }

hexagonal/src/test/java/com/iluwatar/hexagonal/domain/LotteryTicketCheckResultTest.java

@@ -23,25 +23,23 @@
 
 package com.iluwatar.hexagonal.domain;
 
-import com.iluwatar.hexagonal.domain.LotteryTicketCheckResult.CheckResult;
-import org.junit.jupiter.api.Test;
-
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotEquals;
 
+import com.iluwatar.hexagonal.domain.LotteryTicketCheckResult.CheckResult;
+import org.junit.jupiter.api.Test;
+
 /**
- * 
  * Unit tests for {@link LotteryTicketCheckResult}
- *
  */
 class LotteryTicketCheckResultTest {
 
   @Test
   void testEquals() {
-    LotteryTicketCheckResult result1 = new LotteryTicketCheckResult(CheckResult.NO_PRIZE);
+    var result1 = new LotteryTicketCheckResult(CheckResult.NO_PRIZE);
-    LotteryTicketCheckResult result2 = new LotteryTicketCheckResult(CheckResult.NO_PRIZE);
+    var result2 = new LotteryTicketCheckResult(CheckResult.NO_PRIZE);
     assertEquals(result1, result2);
-    LotteryTicketCheckResult result3 = new LotteryTicketCheckResult(CheckResult.WIN_PRIZE, 300000);
+    var result3 = new LotteryTicketCheckResult(CheckResult.WIN_PRIZE, 300000);
     assertNotEquals(result1, result3);
-  } 
+  }
 }

hexagonal/src/test/java/com/iluwatar/hexagonal/domain/LotteryTicketIdTest.java

@@ -23,11 +23,11 @@
 
 package com.iluwatar.hexagonal.domain;
 
-import org.junit.jupiter.api.Test;
-
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotEquals;
 
+import org.junit.jupiter.api.Test;
+
 /**
  * Tests for lottery ticket id
  */
@@ -35,12 +35,12 @@ class LotteryTicketIdTest {
 
   @Test
   void testEquals() {
-    LotteryTicketId ticketId1 = new LotteryTicketId();
+    var ticketId1 = new LotteryTicketId();
-    LotteryTicketId ticketId2 = new LotteryTicketId();
+    var ticketId2 = new LotteryTicketId();
-    LotteryTicketId ticketId3 = new LotteryTicketId();
+    var ticketId3 = new LotteryTicketId();
     assertNotEquals(ticketId1, ticketId2);
     assertNotEquals(ticketId2, ticketId3);
-    LotteryTicketId ticketId4 = new LotteryTicketId(ticketId1.getId());
+    var ticketId4 = new LotteryTicketId(ticketId1.getId());
     assertEquals(ticketId1, ticketId4);
   }
 }

hexagonal/src/test/java/com/iluwatar/hexagonal/domain/LotteryTicketTest.java

@@ -23,13 +23,12 @@
 
 package com.iluwatar.hexagonal.domain;
 
-import org.junit.jupiter.api.Test;
-
-import java.util.Set;
-
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotEquals;
 
+import java.util.Set;
+import org.junit.jupiter.api.Test;
+
 /**
  * Test Lottery Tickets for equality
  */
@@ -37,16 +36,16 @@ class LotteryTicketTest {
 
   @Test
   void testEquals() {
-    PlayerDetails details1 = new PlayerDetails("bob@foo.bar", "1212-121212", "+34332322");
+    var details1 = new PlayerDetails("bob@foo.bar", "1212-121212", "+34332322");
-    LotteryNumbers numbers1 = LotteryNumbers.create(Set.of(1, 2, 3, 4));
+    var numbers1 = LotteryNumbers.create(Set.of(1, 2, 3, 4));
-    LotteryTicket ticket1 = new LotteryTicket(new LotteryTicketId(), details1, numbers1);
+    var ticket1 = new LotteryTicket(new LotteryTicketId(), details1, numbers1);
-    PlayerDetails details2 = new PlayerDetails("bob@foo.bar", "1212-121212", "+34332322");
+    var details2 = new PlayerDetails("bob@foo.bar", "1212-121212", "+34332322");
-    LotteryNumbers numbers2 = LotteryNumbers.create(Set.of(1, 2, 3, 4));
+    var numbers2 = LotteryNumbers.create(Set.of(1, 2, 3, 4));
-    LotteryTicket ticket2 = new LotteryTicket(new LotteryTicketId(), details2, numbers2);
+    var ticket2 = new LotteryTicket(new LotteryTicketId(), details2, numbers2);
     assertEquals(ticket1, ticket2);
-    PlayerDetails details3 = new PlayerDetails("elsa@foo.bar", "1223-121212", "+49332322");
+    var details3 = new PlayerDetails("elsa@foo.bar", "1223-121212", "+49332322");
-    LotteryNumbers numbers3 = LotteryNumbers.create(Set.of(1, 2, 3, 8));
+    var numbers3 = LotteryNumbers.create(Set.of(1, 2, 3, 8));
-    LotteryTicket ticket3 = new LotteryTicket(new LotteryTicketId(), details3, numbers3);
+    var ticket3 = new LotteryTicket(new LotteryTicketId(), details3, numbers3);
     assertNotEquals(ticket1, ticket3);
   }
 }

hexagonal/src/test/java/com/iluwatar/hexagonal/domain/PlayerDetailsTest.java

@@ -23,24 +23,22 @@
 
 package com.iluwatar.hexagonal.domain;
 
-import org.junit.jupiter.api.Test;
-
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotEquals;
 
+import org.junit.jupiter.api.Test;
+
 /**
- * 
  * Unit tests for {@link PlayerDetails}
- *
  */
 class PlayerDetailsTest {
 
   @Test
   void testEquals() {
-    PlayerDetails details1 = new PlayerDetails("tom@foo.bar", "11212-123434", "+12323425");
+    var details1 = new PlayerDetails("tom@foo.bar", "11212-123434", "+12323425");
-    PlayerDetails details2 = new PlayerDetails("tom@foo.bar", "11212-123434", "+12323425");
+    var details2 = new PlayerDetails("tom@foo.bar", "11212-123434", "+12323425");
     assertEquals(details1, details2);
-    PlayerDetails details3 = new PlayerDetails("john@foo.bar", "16412-123439", "+34323432");
+    var details3 = new PlayerDetails("john@foo.bar", "16412-123439", "+34323432");
     assertNotEquals(details1, details3);
-  }  
+  }
 }

hexagonal/src/test/java/com/iluwatar/hexagonal/eventlog/MongoEventLogTest.java

@@ -23,6 +23,8 @@
 
 package com.iluwatar.hexagonal.eventlog;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 import com.iluwatar.hexagonal.domain.PlayerDetails;
 import com.iluwatar.hexagonal.mongo.MongoConnectionPropertiesLoader;
 import com.mongodb.MongoClient;
@@ -30,8 +32,6 @@ import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
 /**
  * Tests for Mongo event log
  */
@@ -46,7 +46,7 @@ class MongoEventLogTest {
   @BeforeEach
   void init() {
     MongoConnectionPropertiesLoader.load();
-    MongoClient mongoClient = new MongoClient(System.getProperty("mongo-host"),
+    var mongoClient = new MongoClient(System.getProperty("mongo-host"),
         Integer.parseInt(System.getProperty("mongo-port")));
     mongoClient.dropDatabase(TEST_DB);
     mongoClient.close();
@@ -60,7 +60,7 @@ class MongoEventLogTest {
 
   @Test
   void testFundTransfers() {
-    PlayerDetails playerDetails = new PlayerDetails("john@wayne.com", "000-000", "03432534543");
+    var playerDetails = new PlayerDetails("john@wayne.com", "000-000", "03432534543");
     mongoEventLog.prizeError(playerDetails, 1000);
     assertEquals(1, mongoEventLog.getEventsCollection().count());
     mongoEventLog.prizeError(playerDetails, 1000);

hexagonal/src/test/java/com/iluwatar/hexagonal/test/LotteryTestUtils.java

@@ -27,13 +27,10 @@ import com.iluwatar.hexagonal.domain.LotteryNumbers;
 import com.iluwatar.hexagonal.domain.LotteryTicket;
 import com.iluwatar.hexagonal.domain.LotteryTicketId;
 import com.iluwatar.hexagonal.domain.PlayerDetails;
-
 import java.util.Set;
 
 /**
- * 
  * Utilities for lottery tests
- *
  */
 public class LotteryTestUtils {
 
@@ -43,14 +40,14 @@ public class LotteryTestUtils {
   public static LotteryTicket createLotteryTicket() {
     return createLotteryTicket("foo@bar.com", "12231-213132", "+99324554", Set.of(1, 2, 3, 4));
   }
-  
+
   /**
    * @return lottery ticket
    */
   public static LotteryTicket createLotteryTicket(String email, String account, String phone,
-      Set<Integer> givenNumbers) {
+                                                  Set<Integer> givenNumbers) {
-    PlayerDetails details = new PlayerDetails(email, account, phone);
+    var details = new PlayerDetails(email, account, phone);
-    LotteryNumbers numbers = LotteryNumbers.create(givenNumbers);
+    var numbers = LotteryNumbers.create(givenNumbers);
     return new LotteryTicket(new LotteryTicketId(), details, numbers);
   }
 }

intercepting-filter/src/main/java/com/iluwatar/intercepting/filter/AddressFilter.java

@@ -33,7 +33,7 @@ public class AddressFilter extends AbstractFilter {
 
   @Override
   public String execute(Order order) {
-    String result = super.execute(order);
+    var result = super.execute(order);
     if (order.getAddress() == null || order.getAddress().isEmpty()) {
       return result + "Invalid address! ";
     } else {

intercepting-filter/src/main/java/com/iluwatar/intercepting/filter/App.java

@@ -54,14 +54,14 @@ public class App {
    * @param args command line args
    */
   public static void main(String[] args) {
-    FilterManager filterManager = new FilterManager();
+    var filterManager = new FilterManager();
     filterManager.addFilter(new NameFilter());
     filterManager.addFilter(new ContactFilter());
     filterManager.addFilter(new AddressFilter());
     filterManager.addFilter(new DepositFilter());
     filterManager.addFilter(new OrderFilter());
 
-    Client client = new Client();
+    var client = new Client();
     client.setFilterManager(filterManager);
   }
 }

intercepting-filter/src/main/java/com/iluwatar/intercepting/filter/Client.java

@@ -25,7 +25,8 @@ package com.iluwatar.intercepting.filter;
 
 import java.awt.BorderLayout;
 import java.awt.GridLayout;
-
+import java.awt.event.ActionEvent;
+import java.util.Arrays;
 import javax.swing.JButton;
 import javax.swing.JFrame;
 import javax.swing.JLabel;
@@ -65,11 +66,11 @@ public class Client extends JFrame { // NOSONAR
     setSize(300, 300);
     jl = new JLabel("RUNNING...");
     jtFields = new JTextField[3];
-    for (int i = 0; i < 3; i++) {
+    for (var i = 0; i < 3; i++) {
       jtFields[i] = new JTextField();
     }
     jtAreas = new JTextArea[2];
-    for (int i = 0; i < 2; i++) {
+    for (var i = 0; i < 2; i++) {
       jtAreas[i] = new JTextArea();
     }
     clearButton = new JButton("Clear");
@@ -80,7 +81,7 @@ public class Client extends JFrame { // NOSONAR
 
   private void setup() {
     setLayout(new BorderLayout());
-    JPanel panel = new JPanel();
+    var panel = new JPanel();
     add(jl, BorderLayout.SOUTH);
     add(panel, BorderLayout.CENTER);
     panel.setLayout(new GridLayout(6, 2));
@@ -98,21 +99,11 @@ public class Client extends JFrame { // NOSONAR
     panel.add(processButton);
 
     clearButton.addActionListener(e -> {
-      for (JTextArea i : jtAreas) {
+      Arrays.stream(jtAreas).forEach(i -> i.setText(""));
-        i.setText("");
+      Arrays.stream(jtFields).forEach(i -> i.setText(""));
-      }
-      for (JTextField i : jtFields) {
-        i.setText("");
-      }
     });
 
-    processButton.addActionListener(e -> {
+    processButton.addActionListener(this::actionPerformed);
-      Order order =
-          new Order(jtFields[0].getText(), jtFields[1].getText(), jtAreas[0].getText(), jtFields[2]
-              .getText(),
-              jtAreas[1].getText());
-      jl.setText(sendRequest(order));
-    });
 
     JRootPane rootPane = SwingUtilities.getRootPane(processButton);
     rootPane.setDefaultButton(processButton);
@@ -126,4 +117,14 @@ public class Client extends JFrame { // NOSONAR
   public String sendRequest(Order order) {
     return filterManager.filterRequest(order);
   }
+
+  private void actionPerformed(ActionEvent e) {
+    var fieldText1 = jtFields[0].getText();
+    var fieldText2 = jtFields[1].getText();
+    var areaText1 = jtAreas[0].getText();
+    var fieldText3 = jtFields[2].getText();
+    var areaText2 = jtAreas[1].getText();
+    var order = new Order(fieldText1, fieldText2, areaText1, fieldText3, areaText2);
+    jl.setText(sendRequest(order));
+  }
 }

intercepting-filter/src/main/java/com/iluwatar/intercepting/filter/ContactFilter.java

@@ -34,10 +34,11 @@ public class ContactFilter extends AbstractFilter {
 
   @Override
   public String execute(Order order) {
-    String result = super.execute(order);
+    var result = super.execute(order);
-    if (order.getContactNumber() == null || order.getContactNumber().isEmpty()
+    var contactNumber = order.getContactNumber();
-        || order.getContactNumber().matches(".*[^\\d]+.*")
+    if (contactNumber == null || contactNumber.isEmpty()
-        || order.getContactNumber().length() != 11) {
+        || contactNumber.matches(".*[^\\d]+.*")
+        || contactNumber.length() != 11) {
       return result + "Invalid contact number! ";
     } else {
       return result;

intercepting-filter/src/main/java/com/iluwatar/intercepting/filter/DepositFilter.java

@@ -32,8 +32,9 @@ public class DepositFilter extends AbstractFilter {
 
   @Override
   public String execute(Order order) {
-    String result = super.execute(order);
+    var result = super.execute(order);
-    if (order.getDepositNumber() == null || order.getDepositNumber().isEmpty()) {
+    var depositNumber = order.getDepositNumber();
+    if (depositNumber == null || depositNumber.isEmpty()) {
       return result + "Invalid deposit number! ";
     } else {
       return result;

intercepting-filter/src/main/java/com/iluwatar/intercepting/filter/NameFilter.java

@@ -33,9 +33,9 @@ public class NameFilter extends AbstractFilter {
 
   @Override
   public String execute(Order order) {
-    String result = super.execute(order);
+    var result = super.execute(order);
-    if (order.getName() == null || order.getName().isEmpty()
+    var name = order.getName();
-        || order.getName().matches(".*[^\\w|\\s]+.*")) {
+    if (name == null || name.isEmpty() || name.matches(".*[^\\w|\\s]+.*")) {
       return result + "Invalid name! ";
     } else {
       return result;

intercepting-filter/src/main/java/com/iluwatar/intercepting/filter/OrderFilter.java

@@ -32,8 +32,9 @@ public class OrderFilter extends AbstractFilter {
 
   @Override
   public String execute(Order order) {
-    String result = super.execute(order);
+    var result = super.execute(order);
-    if (order.getOrderItem() == null || order.getOrderItem().isEmpty()) {
+    var orderItem = order.getOrderItem();
+    if (orderItem == null || orderItem.isEmpty()) {
       return result + "Invalid order! ";
     } else {
       return result;

intercepting-filter/src/main/java/com/iluwatar/intercepting/filter/Target.java

@@ -27,11 +27,10 @@ import java.awt.BorderLayout;
 import java.awt.Dimension;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
-
+import java.util.stream.IntStream;
 import javax.swing.JButton;
 import javax.swing.JFrame;
 import javax.swing.JPanel;
-import javax.swing.JRootPane;
 import javax.swing.JScrollPane;
 import javax.swing.JTable;
 import javax.swing.SwingUtilities;
@@ -58,9 +57,8 @@ public class Target extends JFrame { //NOSONAR
     super("Order System");
     setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
     setSize(640, 480);
-    dtm =
+    dtm = new DefaultTableModel(
-        new DefaultTableModel(new Object[]{"Name", "Contact Number", "Address", "Deposit Number",
+        new Object[]{"Name", "Contact Number", "Address", "Deposit Number", "Order"}, 0);
-            "Order"}, 0);
     jt = new JTable(dtm);
     del = new JButton("Delete");
     setup();
@@ -68,18 +66,18 @@ public class Target extends JFrame { //NOSONAR
 
   private void setup() {
     setLayout(new BorderLayout());
-    JPanel bot = new JPanel();
+    var bot = new JPanel();
     add(jt.getTableHeader(), BorderLayout.NORTH);
     bot.setLayout(new BorderLayout());
     bot.add(del, BorderLayout.EAST);
     add(bot, BorderLayout.SOUTH);
-    JScrollPane jsp = new JScrollPane(jt);
+    var jsp = new JScrollPane(jt);
     jsp.setPreferredSize(new Dimension(500, 250));
     add(jsp, BorderLayout.CENTER);
 
     del.addActionListener(new DListener());
 
-    JRootPane rootPane = SwingUtilities.getRootPane(del);
+    var rootPane = SwingUtilities.getRootPane(del);
     rootPane.setDefaultButton(del);
     setVisible(true);
   }
@@ -91,14 +89,12 @@ public class Target extends JFrame { //NOSONAR
   class DListener implements ActionListener {
     @Override
     public void actionPerformed(ActionEvent e) {
-      int temp = jt.getSelectedRow();
+      var temp = jt.getSelectedRow();
       if (temp == -1) {
         return;
       }
-      int temp2 = jt.getSelectedRowCount();
+      var temp2 = jt.getSelectedRowCount();
-      for (int i = 0; i < temp2; i++) {
+      IntStream.range(0, temp2).forEach(i -> dtm.removeRow(temp));
-        dtm.removeRow(temp);
-      }
     }
   }
 }

intercepting-filter/src/test/java/com/iluwatar/intercepting/filter/AppTest.java

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

intercepting-filter/src/test/java/com/iluwatar/intercepting/filter/FilterManagerTest.java

@@ -23,8 +23,6 @@
 
 package com.iluwatar.intercepting.filter;
 
-import org.junit.jupiter.api.Test;
-
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.mockito.Matchers.any;
 import static org.mockito.Mockito.mock;
@@ -33,6 +31,8 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyZeroInteractions;
 import static org.mockito.Mockito.when;
 
+import org.junit.jupiter.api.Test;
+
 /**
  * Date: 12/13/15 - 3:01 PM
  *
@@ -42,20 +42,20 @@ public class FilterManagerTest {
 
   @Test
   public void testFilterRequest() {
-    final Target target = mock(Target.class);
+    final var target = mock(Target.class);
-    final FilterManager filterManager = new FilterManager();
+    final var filterManager = new FilterManager();
     assertEquals("RUNNING...", filterManager.filterRequest(mock(Order.class)));
     verifyZeroInteractions(target);
   }
 
   @Test
   public void testAddFilter() {
-    final Target target = mock(Target.class);
+    final var target = mock(Target.class);
-    final FilterManager filterManager = new FilterManager();
+    final var filterManager = new FilterManager();
 
     verifyZeroInteractions(target);
 
-    final Filter filter = mock(Filter.class);
+    final var filter = mock(Filter.class);
     when(filter.execute(any(Order.class))).thenReturn("filter");
 
     filterManager.addFilter(filter);

intercepting-filter/src/test/java/com/iluwatar/intercepting/filter/FilterTest.java

@@ -23,17 +23,15 @@
 
 package com.iluwatar.intercepting.filter;
 
-import org.junit.jupiter.params.ParameterizedTest;
-import org.junit.jupiter.params.provider.MethodSource;
-
-import java.util.ArrayList;
-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.assertSame;
 
+import java.util.List;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
+
 /**
  * Date: 12/13/15 - 2:17 PM
  *
@@ -41,7 +39,8 @@ import static org.junit.jupiter.api.Assertions.assertSame;
  */
 public class FilterTest {
 
-  private static final Order PERFECT_ORDER = new Order("name", "12345678901", "addr", "dep", "order");
+  private static final Order PERFECT_ORDER =
+      new Order("name", "12345678901", "addr", "dep", "order");
   private static final Order WRONG_ORDER = new Order("name", "12345678901", "addr", "dep", "");
   private static final Order WRONG_DEPOSIT = new Order("name", "12345678901", "addr", "", "order");
   private static final Order WRONG_ADDRESS = new Order("name", "12345678901", "", "dep", "order");
@@ -49,49 +48,48 @@ public class FilterTest {
   private static final Order WRONG_NAME = new Order("", "12345678901", "addr", "dep", "order");
 
   static List<Object[]> getTestData() {
-    final List<Object[]> testData = new ArrayList<>();
+    return List.of(
-    testData.add(new Object[]{new NameFilter(), PERFECT_ORDER, ""});
+        new Object[]{new NameFilter(), PERFECT_ORDER, ""},
-    testData.add(new Object[]{new NameFilter(), WRONG_NAME, "Invalid name!"});
+        new Object[]{new NameFilter(), WRONG_NAME, "Invalid name!"},
-    testData.add(new Object[]{new NameFilter(), WRONG_CONTACT, ""});
+        new Object[]{new NameFilter(), WRONG_CONTACT, ""},
-    testData.add(new Object[]{new NameFilter(), WRONG_ADDRESS, ""});
+        new Object[]{new NameFilter(), WRONG_ADDRESS, ""},
-    testData.add(new Object[]{new NameFilter(), WRONG_DEPOSIT, ""});
+        new Object[]{new NameFilter(), WRONG_DEPOSIT, ""},
-    testData.add(new Object[]{new NameFilter(), WRONG_ORDER, ""});
+        new Object[]{new NameFilter(), WRONG_ORDER, ""},
 
-    testData.add(new Object[]{new ContactFilter(), PERFECT_ORDER, ""});
+        new Object[]{new ContactFilter(), PERFECT_ORDER, ""},
-    testData.add(new Object[]{new ContactFilter(), WRONG_NAME, ""});
+        new Object[]{new ContactFilter(), WRONG_NAME, ""},
-    testData.add(new Object[]{new ContactFilter(), WRONG_CONTACT, "Invalid contact number!"});
+        new Object[]{new ContactFilter(), WRONG_CONTACT, "Invalid contact number!"},
-    testData.add(new Object[]{new ContactFilter(), WRONG_ADDRESS, ""});
+        new Object[]{new ContactFilter(), WRONG_ADDRESS, ""},
-    testData.add(new Object[]{new ContactFilter(), WRONG_DEPOSIT, ""});
+        new Object[]{new ContactFilter(), WRONG_DEPOSIT, ""},
-    testData.add(new Object[]{new ContactFilter(), WRONG_ORDER, ""});
+        new Object[]{new ContactFilter(), WRONG_ORDER, ""},
 
-    testData.add(new Object[]{new AddressFilter(), PERFECT_ORDER, ""});
+        new Object[]{new AddressFilter(), PERFECT_ORDER, ""},
-    testData.add(new Object[]{new AddressFilter(), WRONG_NAME, ""});
+        new Object[]{new AddressFilter(), WRONG_NAME, ""},
-    testData.add(new Object[]{new AddressFilter(), WRONG_CONTACT, ""});
+        new Object[]{new AddressFilter(), WRONG_CONTACT, ""},
-    testData.add(new Object[]{new AddressFilter(), WRONG_ADDRESS, "Invalid address!"});
+        new Object[]{new AddressFilter(), WRONG_ADDRESS, "Invalid address!"},
-    testData.add(new Object[]{new AddressFilter(), WRONG_DEPOSIT, ""});
+        new Object[]{new AddressFilter(), WRONG_DEPOSIT, ""},
-    testData.add(new Object[]{new AddressFilter(), WRONG_ORDER, ""});
+        new Object[]{new AddressFilter(), WRONG_ORDER, ""},
 
-    testData.add(new Object[]{new DepositFilter(), PERFECT_ORDER, ""});
+        new Object[]{new DepositFilter(), PERFECT_ORDER, ""},
-    testData.add(new Object[]{new DepositFilter(), WRONG_NAME, ""});
+        new Object[]{new DepositFilter(), WRONG_NAME, ""},
-    testData.add(new Object[]{new DepositFilter(), WRONG_CONTACT, ""});
+        new Object[]{new DepositFilter(), WRONG_CONTACT, ""},
-    testData.add(new Object[]{new DepositFilter(), WRONG_ADDRESS, ""});
+        new Object[]{new DepositFilter(), WRONG_ADDRESS, ""},
-    testData.add(new Object[]{new DepositFilter(), WRONG_DEPOSIT, "Invalid deposit number!"});
+        new Object[]{new DepositFilter(), WRONG_DEPOSIT, "Invalid deposit number!"},
-    testData.add(new Object[]{new DepositFilter(), WRONG_ORDER, ""});
+        new Object[]{new DepositFilter(), WRONG_ORDER, ""},
 
-    testData.add(new Object[]{new OrderFilter(), PERFECT_ORDER, ""});
+        new Object[]{new OrderFilter(), PERFECT_ORDER, ""},
-    testData.add(new Object[]{new OrderFilter(), WRONG_NAME, ""});
+        new Object[]{new OrderFilter(), WRONG_NAME, ""},
-    testData.add(new Object[]{new OrderFilter(), WRONG_CONTACT, ""});
+        new Object[]{new OrderFilter(), WRONG_CONTACT, ""},
-    testData.add(new Object[]{new OrderFilter(), WRONG_ADDRESS, ""});
+        new Object[]{new OrderFilter(), WRONG_ADDRESS, ""},
-    testData.add(new Object[]{new OrderFilter(), WRONG_DEPOSIT, ""});
+        new Object[]{new OrderFilter(), WRONG_DEPOSIT, ""},
-    testData.add(new Object[]{new OrderFilter(), WRONG_ORDER, "Invalid order!"});
+        new Object[]{new OrderFilter(), WRONG_ORDER, "Invalid order!"}
-
+    );
-    return testData;
   }
 
   @ParameterizedTest
   @MethodSource("getTestData")
   public void testExecute(Filter filter, Order order, String expectedResult) {
-    final String result = filter.execute(order);
+    final var result = filter.execute(order);
     assertNotNull(result);
     assertEquals(expectedResult, result.trim());
   }

intercepting-filter/src/test/java/com/iluwatar/intercepting/filter/OrderTest.java

@@ -23,10 +23,10 @@
 
 package com.iluwatar.intercepting.filter;
 
-import org.junit.jupiter.api.Test;
-
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
+import org.junit.jupiter.api.Test;
+
 /**
  * Date: 12/13/15 - 2:57 PM
  *
@@ -38,35 +38,35 @@ public class OrderTest {
 
   @Test
   public void testSetName() {
-    final Order order = new Order();
+    final var order = new Order();
     order.setName(EXPECTED_VALUE);
     assertEquals(EXPECTED_VALUE, order.getName());
   }
 
   @Test
   public void testSetContactNumber() {
-    final Order order = new Order();
+    final var order = new Order();
     order.setContactNumber(EXPECTED_VALUE);
     assertEquals(EXPECTED_VALUE, order.getContactNumber());
   }
 
   @Test
   public void testSetAddress() {
-    final Order order = new Order();
+    final var order = new Order();
     order.setAddress(EXPECTED_VALUE);
     assertEquals(EXPECTED_VALUE, order.getAddress());
   }
 
   @Test
   public void testSetDepositNumber() {
-    final Order order = new Order();
+    final var order = new Order();
     order.setDepositNumber(EXPECTED_VALUE);
     assertEquals(EXPECTED_VALUE, order.getDepositNumber());
   }
 
   @Test
   public void testSetOrder() {
-    final Order order = new Order();
+    final var order = new Order();
     order.setOrderItem(EXPECTED_VALUE);
     assertEquals(EXPECTED_VALUE, order.getOrderItem());
   }

interpreter/src/main/java/com/iluwatar/interpreter/App.java

@@ -49,24 +49,24 @@ public class App {
    * @param args command line args
    */
   public static void main(String[] args) {
-    String tokenString = "4 3 2 - 1 + *";
+    var tokenString = "4 3 2 - 1 + *";
-    Stack<Expression> stack = new Stack<>();
+    var stack = new Stack<Expression>();
 
-    String[] tokenList = tokenString.split(" ");
+    var tokenList = tokenString.split(" ");
-    for (String s : tokenList) {
+    for (var s : tokenList) {
       if (isOperator(s)) {
-        Expression rightExpression = stack.pop();
+        var rightExpression = stack.pop();
-        Expression leftExpression = stack.pop();
+        var leftExpression = stack.pop();
         LOGGER.info("popped from stack left: {} right: {}",
             leftExpression.interpret(), rightExpression.interpret());
-        Expression operator = getOperatorInstance(s, leftExpression, rightExpression);
+        var operator = getOperatorInstance(s, leftExpression, rightExpression);
         LOGGER.info("operator: {}", operator);
-        int result = operator.interpret();
+        var result = operator.interpret();
-        NumberExpression resultExpression = new NumberExpression(result);
+        var resultExpression = new NumberExpression(result);
         stack.push(resultExpression);
         LOGGER.info("push result to stack: {}", resultExpression.interpret());
       } else {
-        Expression i = new NumberExpression(s);
+        var i = new NumberExpression(s);
         stack.push(i);
         LOGGER.info("push to stack: {}", i.interpret());
       }

interpreter/src/test/java/com/iluwatar/interpreter/AppTest.java

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

interpreter/src/test/java/com/iluwatar/interpreter/ExpressionTest.java

@@ -23,25 +23,23 @@
 
 package com.iluwatar.interpreter;
 
-import org.junit.jupiter.api.Disabled;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+import java.util.ArrayList;
+import java.util.function.BiFunction;
+import java.util.function.IntBinaryOperator;
+import java.util.stream.Stream;
 import org.junit.jupiter.api.TestInstance;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
 
-import java.util.ArrayList;
-import java.util.List;
-import java.util.function.BiFunction;
-import java.util.function.IntBinaryOperator;
-import java.util.stream.Stream;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertNotNull;
-
 /**
  * Date: 12/14/15 - 11:48 AM
- *
+ * <p>
  * Test Case for Expressions
+ *
  * @param <E> Type of Expression
  * @author Jeroen Meulemeester
  */
@@ -55,13 +53,13 @@ public abstract class ExpressionTest<E extends Expression> {
    * @return A stream with test entries
    */
   static Stream<Arguments> prepareParameters(final IntBinaryOperator resultCalc) {
-    final List<Arguments> testData = new ArrayList<>();
+    final var testData = new ArrayList<Arguments>();
-    for (int i = -10; i < 10; i++) {
+    for (var i = -10; i < 10; i++) {
-      for (int j = -10; j < 10; j++) {
+      for (var j = -10; j < 10; j++) {
         testData.add(Arguments.of(
-                new NumberExpression(i),
+            new NumberExpression(i),
-                new NumberExpression(j),
+            new NumberExpression(j),
-                resultCalc.applyAsInt(i, j)
+            resultCalc.applyAsInt(i, j)
         ));
       }
     }
@@ -104,7 +102,7 @@ public abstract class ExpressionTest<E extends Expression> {
   @ParameterizedTest
   @MethodSource("expressionProvider")
   public void testInterpret(NumberExpression first, NumberExpression second, int result) {
-    final E expression = factory.apply(first, second);
+    final var expression = factory.apply(first, second);
     assertNotNull(expression);
     assertEquals(result, expression.interpret());
   }
@@ -115,7 +113,7 @@ public abstract class ExpressionTest<E extends Expression> {
   @ParameterizedTest
   @MethodSource("expressionProvider")
   public void testToString(NumberExpression first, NumberExpression second) {
-    final E expression = factory.apply(first, second);
+    final var expression = factory.apply(first, second);
     assertNotNull(expression);
     assertEquals(expectedToString, expression.toString());
   }

interpreter/src/test/java/com/iluwatar/interpreter/MinusExpressionTest.java

@@ -23,9 +23,8 @@
 
 package com.iluwatar.interpreter;
 
-import org.junit.jupiter.params.provider.Arguments;
-
 import java.util.stream.Stream;
+import org.junit.jupiter.params.provider.Arguments;
 
 /**
  * Date: 12/14/15 - 12:08 PM

interpreter/src/test/java/com/iluwatar/interpreter/MultiplyExpressionTest.java

@@ -23,9 +23,8 @@
 
 package com.iluwatar.interpreter;
 
-import org.junit.jupiter.params.provider.Arguments;
-
 import java.util.stream.Stream;
+import org.junit.jupiter.params.provider.Arguments;
 
 /**
  * Date: 12/14/15 - 12:08 PM
@@ -46,7 +45,6 @@ public class MultiplyExpressionTest extends ExpressionTest<MultiplyExpression> {
 
   /**
    * Create a new test instance using the given test parameters and expected result
-   *
    */
   public MultiplyExpressionTest() {
     super("*", MultiplyExpression::new);

interpreter/src/test/java/com/iluwatar/interpreter/NumberExpressionTest.java

@@ -23,14 +23,13 @@
 
 package com.iluwatar.interpreter;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.stream.Stream;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
 
-import java.util.stream.Stream;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
 /**
  * Date: 12/14/15 - 12:08 PM
  *
@@ -61,9 +60,9 @@ public class NumberExpressionTest extends ExpressionTest<NumberExpression> {
   @ParameterizedTest
   @MethodSource("expressionProvider")
   public void testFromString(NumberExpression first) throws Exception {
-    final int expectedValue = first.interpret();
+    final var expectedValue = first.interpret();
-    final String testStringValue = String.valueOf(expectedValue);
+    final var testStringValue = String.valueOf(expectedValue);
-    final NumberExpression numberExpression = new NumberExpression(testStringValue);
+    final var numberExpression = new NumberExpression(testStringValue);
     assertEquals(expectedValue, numberExpression.interpret());
   }
 

interpreter/src/test/java/com/iluwatar/interpreter/PlusExpressionTest.java

@@ -23,9 +23,8 @@
 
 package com.iluwatar.interpreter;
 
-import org.junit.jupiter.params.provider.Arguments;
-
 import java.util.stream.Stream;
+import org.junit.jupiter.params.provider.Arguments;
 
 /**
  * Date: 12/14/15 - 12:08 PM
@@ -41,7 +40,7 @@ public class PlusExpressionTest extends ExpressionTest<PlusExpression> {
    */
   @Override
   public Stream<Arguments> expressionProvider() {
-    return prepareParameters((f, s) -> f + s);
+    return prepareParameters(Integer::sum);
   }
 
   /**

iterator/src/main/java/com/iluwatar/iterator/App.java

@@ -30,7 +30,6 @@ import static com.iluwatar.iterator.list.ItemType.WEAPON;
 
 import com.iluwatar.iterator.bst.BstIterator;
 import com.iluwatar.iterator.bst.TreeNode;
-import com.iluwatar.iterator.list.Item;
 import com.iluwatar.iterator.list.ItemType;
 import com.iluwatar.iterator.list.TreasureChest;
 import org.slf4j.Logger;
@@ -53,7 +52,7 @@ public class App {
   private static void demonstrateTreasureChestIteratorForType(ItemType itemType) {
     LOGGER.info("------------------------");
     LOGGER.info("Item Iterator for ItemType " + itemType + ": ");
-    Iterator<Item> itemIterator = TREASURE_CHEST.iterator(itemType);
+    var itemIterator = TREASURE_CHEST.iterator(itemType);
     while (itemIterator.hasNext()) {
       LOGGER.info(itemIterator.next().toString());
     }
@@ -62,15 +61,15 @@ public class App {
   private static void demonstrateBstIterator() {
     LOGGER.info("------------------------");
     LOGGER.info("BST Iterator: ");
-    TreeNode<Integer> root = buildIntegerBst();
+    var root = buildIntegerBst();
-    BstIterator bstIterator = new BstIterator<>(root);
+    var bstIterator = new BstIterator<Integer>(root);
     while (bstIterator.hasNext()) {
       LOGGER.info("Next node: " + bstIterator.next().getVal());
     }
   }
 
   private static TreeNode<Integer> buildIntegerBst() {
-    TreeNode<Integer> root = new TreeNode<>(8);
+    var root = new TreeNode<>(8);
 
     root.insert(3);
     root.insert(10);

iterator/src/main/java/com/iluwatar/iterator/bst/BstIterator.java

@@ -78,7 +78,7 @@ public class BstIterator<T extends Comparable<T>> implements Iterator<TreeNode<T
     if (pathStack.isEmpty()) {
       throw new NoSuchElementException();
     }
-    TreeNode<T> next = pathStack.pop();
+    var next = pathStack.pop();
     pushPathToNextSmallest(next.getRight());
     return next;
   }

iterator/src/main/java/com/iluwatar/iterator/bst/README.md

@@ -63,7 +63,7 @@ public TreeNode next() throws IllegalStateException {
   if (pathStack.isEmpty()) {
     throw new IllegalStateException();
   }
-  TreeNode next = pathStack.pop();
+  var next = pathStack.pop();
   // follow right child to next smallest node
   pushPathToNextSmallest(next.getRight());
   return next;

iterator/src/main/java/com/iluwatar/iterator/bst/TreeNode.java

@@ -72,7 +72,7 @@ public class TreeNode<T extends Comparable<T>> {
    * @param valToInsert The value to insert as a new TreeNode
    */
   public void insert(T valToInsert) {
-    TreeNode<T> parent = getParentNodeOfValueToBeInserted(valToInsert);
+    var parent = getParentNodeOfValueToBeInserted(valToInsert);
     parent.insertNewChild(valToInsert);
   }
 
@@ -84,7 +84,7 @@ public class TreeNode<T extends Comparable<T>> {
    */
   private TreeNode<T> getParentNodeOfValueToBeInserted(T valToInsert) {
     TreeNode<T> parent = null;
-    TreeNode<T> curr = this;
+    var curr = this;
 
     while (curr != null) {
       parent = curr;

iterator/src/main/java/com/iluwatar/iterator/list/TreasureChestItemIterator.java

@@ -24,7 +24,6 @@
 package com.iluwatar.iterator.list;
 
 import com.iluwatar.iterator.Iterator;
-import java.util.List;
 
 /**
  * TreasureChestItemIterator.
@@ -59,10 +58,9 @@ public class TreasureChestItemIterator implements Iterator<Item> {
   }
 
   private int findNextIdx() {
-    List<Item> items = chest.getItems();
+    var items = chest.getItems();
-    boolean found = false;
+    var tempIdx = idx;
-    int tempIdx = idx;
+    while (true) {
-    while (!found) {
       tempIdx++;
       if (tempIdx >= items.size()) {
         tempIdx = -1;

iterator/src/test/java/com/iluwatar/iterator/AppTest.java

@@ -32,7 +32,6 @@ class AppTest {
 
   @Test
   void testApp() {
-    String[] args = {};
+    App.main(new String[]{});
-    App.main(args);
   }
 } 

iterator/src/test/java/com/iluwatar/iterator/bst/BstIteratorTest.java

@@ -28,13 +28,12 @@ import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
+import java.util.NoSuchElementException;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.TestInstance;
 import org.junit.jupiter.api.TestInstance.Lifecycle;
 
-import java.util.NoSuchElementException;
-
 @TestInstance(Lifecycle.PER_CLASS)
 class BstIteratorTest {
 
@@ -55,14 +54,14 @@ class BstIteratorTest {
 
   @Test
   void nextForEmptyTree() {
-    BstIterator<Integer> iter = new BstIterator<>(emptyRoot);
+    var iter = new BstIterator<>(emptyRoot);
     assertThrows(NoSuchElementException.class, iter::next,
         "next() should throw an IllegalStateException if hasNext() is false.");
   }
 
   @Test
   void nextOverEntirePopulatedTree() {
-    BstIterator<Integer> iter = new BstIterator<>(nonEmptyRoot);
+    var iter = new BstIterator<>(nonEmptyRoot);
     assertEquals(Integer.valueOf(1), iter.next().getVal(), "First Node is 1.");
     assertEquals(Integer.valueOf(3), iter.next().getVal(), "Second Node is 3.");
     assertEquals(Integer.valueOf(4), iter.next().getVal(), "Third Node is 4.");
@@ -73,19 +72,19 @@ class BstIteratorTest {
 
   @Test
   void hasNextForEmptyTree() {
-    BstIterator<Integer> iter = new BstIterator<>(emptyRoot);
+    var iter = new BstIterator<>(emptyRoot);
     assertFalse(iter.hasNext(), "hasNext() should return false for empty tree.");
   }
 
   @Test
   void hasNextForPopulatedTree() {
-    BstIterator<Integer> iter = new BstIterator<>(nonEmptyRoot);
+    var iter = new BstIterator<>(nonEmptyRoot);
     assertTrue(iter.hasNext(), "hasNext() should return true for populated tree.");
   }
 
   @Test
   void nextAndHasNextOverEntirePopulatedTree() {
-    BstIterator<Integer> iter = new BstIterator<>(nonEmptyRoot);
+    var iter = new BstIterator<>(nonEmptyRoot);
     assertTrue(iter.hasNext(), "Iterator hasNext() should be true.");
     assertEquals(Integer.valueOf(1), iter.next().getVal(), "First Node is 1.");
     assertTrue(iter.hasNext(), "Iterator hasNext() should be true.");

iterator/src/test/java/com/iluwatar/iterator/list/TreasureChestTest.java

@@ -27,7 +27,6 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.fail;
 
-import com.iluwatar.iterator.Iterator;
 import java.util.List;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.MethodSource;
@@ -46,16 +45,16 @@ public class TreasureChestTest {
    */
   public static List<Object[]> dataProvider() {
     return List.of(
-            new Object[]{new Item(ItemType.POTION, "Potion of courage")},
+        new Object[]{new Item(ItemType.POTION, "Potion of courage")},
-            new Object[]{new Item(ItemType.RING, "Ring of shadows")},
+        new Object[]{new Item(ItemType.RING, "Ring of shadows")},
-            new Object[]{new Item(ItemType.POTION, "Potion of wisdom")},
+        new Object[]{new Item(ItemType.POTION, "Potion of wisdom")},
-            new Object[]{new Item(ItemType.POTION, "Potion of blood")},
+        new Object[]{new Item(ItemType.POTION, "Potion of blood")},
-            new Object[]{new Item(ItemType.WEAPON, "Sword of silver +1")},
+        new Object[]{new Item(ItemType.WEAPON, "Sword of silver +1")},
-            new Object[]{new Item(ItemType.POTION, "Potion of rust")},
+        new Object[]{new Item(ItemType.POTION, "Potion of rust")},
-            new Object[]{new Item(ItemType.POTION, "Potion of healing")},
+        new Object[]{new Item(ItemType.POTION, "Potion of healing")},
-            new Object[]{new Item(ItemType.RING, "Ring of armor")},
+        new Object[]{new Item(ItemType.RING, "Ring of armor")},
-            new Object[]{new Item(ItemType.WEAPON, "Steel halberd")},
+        new Object[]{new Item(ItemType.WEAPON, "Steel halberd")},
-            new Object[]{new Item(ItemType.WEAPON, "Dagger of poison")}
+        new Object[]{new Item(ItemType.WEAPON, "Dagger of poison")}
     );
   }
 
@@ -66,16 +65,16 @@ public class TreasureChestTest {
   @ParameterizedTest
   @MethodSource("dataProvider")
   public void testIterator(Item expectedItem) {
-    final TreasureChest chest = new TreasureChest();
+    final var chest = new TreasureChest();
-    final Iterator<Item> iterator = chest.iterator(expectedItem.getType());
+    final var iterator = chest.iterator(expectedItem.getType());
     assertNotNull(iterator);
 
     while (iterator.hasNext()) {
-      final Item item = iterator.next();
+      final var item = iterator.next();
       assertNotNull(item);
       assertEquals(expectedItem.getType(), item.getType());
 
-      final String name = item.toString();
+      final var name = item.toString();
       assertNotNull(name);
       if (expectedItem.toString().equals(name)) {
         return;
@@ -93,17 +92,17 @@ public class TreasureChestTest {
   @ParameterizedTest
   @MethodSource("dataProvider")
   public void testGetItems(Item expectedItem) throws Exception {
-    final TreasureChest chest = new TreasureChest();
+    final var chest = new TreasureChest();
-    final List<Item> items = chest.getItems();
+    final var items = chest.getItems();
     assertNotNull(items);
 
-    for (final Item item : items) {
+    for (final var item : items) {
       assertNotNull(item);
       assertNotNull(item.getType());
       assertNotNull(item.toString());
 
-      final boolean sameType = expectedItem.getType() == item.getType();
+      final var sameType = expectedItem.getType() == item.getType();
-      final boolean sameName = expectedItem.toString().equals(item.toString());
+      final var sameName = expectedItem.toString().equals(item.toString());
       if (sameType && sameName) {
         return;
       }