Resolved PMD issues

event-queue/src/main/java/com/iluwatar/event/queue/App.java

@@ -47,15 +47,13 @@ public class App {
    * @throws IOException when there is a problem with the audio file loading
    * @throws UnsupportedAudioFileException  when the loaded audio file is unsupported 
    */
-  public static void main(String[] args) throws UnsupportedAudioFileException, IOException, InterruptedException {
-    Audio audio = Audio.getInstance();
-    audio.playSound(audio.getAudioStream("./etc/Bass-Drum-1.wav"), -10.0f);
-    audio.playSound(audio.getAudioStream("./etc/Closed-Hi-Hat-1.wav"), -8.0f);
+  public static void main(String[] args) throws UnsupportedAudioFileException, IOException {
+    Audio.playSound(Audio.getAudioStream("./etc/Bass-Drum-1.wav"), -10.0f);
+    Audio.playSound(Audio.getAudioStream("./etc/Closed-Hi-Hat-1.wav"), -8.0f);
     
     System.out.println("Press Enter key to stop the program...");
-    try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {
+    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
     br.read();
-    }
-    audio.stopService();
+    Audio.stopService();
   }
 }

event-queue/src/main/java/com/iluwatar/event/queue/Audio.java

@@ -23,9 +23,6 @@
 
 package com.iluwatar.event.queue;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import java.io.File;
 import java.io.IOException;
 
@@ -41,56 +38,49 @@ import javax.sound.sampled.UnsupportedAudioFileException;
  *
  */
 public class Audio {
-  private static final Logger LOGGER = LoggerFactory.getLogger(Audio.class);
-  private static final Audio INSTANCE = new Audio();
 
   private static final int MAX_PENDING = 16;
 
-  private int headIndex;
+  private static int headIndex;
 
-  private int tailIndex;
+  private static int tailIndex;
 
-  private volatile Thread updateThread = null;
+  private static Thread updateThread = null;
 
-  private PlayMessage[] pendingAudio = new PlayMessage[MAX_PENDING];
-
-  // Visible only for testing purposes
-  Audio() {
-
-  }
-
-  public static Audio getInstance() {
-    return INSTANCE;
-  }
+  private static PlayMessage[] pendingAudio = new PlayMessage[MAX_PENDING];
 
   /**
-   * This method stops the Update Method's thread and waits till service stops.
+   * This method stops the Update Method's thread. 
    */
-  public synchronized void stopService() throws InterruptedException {
+  public static synchronized void stopService() {
     if (updateThread != null) {
       updateThread.interrupt();
     }
-    updateThread.join();
-    updateThread = null;
   }
   
   /**
    * This method check the Update Method's thread is started.
    * @return boolean
    */
-  public synchronized boolean isServiceRunning() {
-    return updateThread != null && updateThread.isAlive();
+  public static synchronized boolean isServiceRunning() {
+    if (updateThread != null && updateThread.isAlive() ) {
+      return true;
+    } else {
+      return false;
+    }
   }
 
   /**
    * Starts the thread for the Update Method pattern if it was not started previously.
    * Also when the thread is is ready initializes the indexes of the queue 
    */
-  public void init() {
+  public static void init() {
     if (updateThread == null) {
-      updateThread = new Thread(() -> {
+      updateThread = new Thread(new Runnable() {
+        public void run() {
           while (!Thread.currentThread().isInterrupted()) {
-          update();
+            Audio.update();
+          }
         }
       });
     }
@@ -100,7 +90,7 @@ public class Audio {
   /**
    * This is a synchronized thread starter
    */
-  private synchronized void startThread() {
+  public static synchronized void startThread() {
     if (!updateThread.isAlive()) {
       updateThread.start();
       headIndex = 0;
@@ -113,7 +103,7 @@ public class Audio {
    * @param stream is the AudioInputStream for the method
    * @param volume is the level of the audio's volume 
    */
-  public void playSound(AudioInputStream stream, float volume) {
+  public static void playSound(AudioInputStream stream, float volume) {
     init();
     // Walk the pending requests.
     for (int i = headIndex; i != tailIndex; i = (i + 1) % MAX_PENDING) {
@@ -133,7 +123,7 @@ public class Audio {
    * This method uses the Update Method pattern.
    * It takes the audio from the queue and plays it
    */
-  private void update() {
+  public static void update() {
     // If there are no pending requests, do nothing.
     if (headIndex == tailIndex) {
       return;
@@ -146,11 +136,13 @@ public class Audio {
       clip.open(audioStream);
       clip.start();
     } catch (LineUnavailableException e) {
-      LOGGER.trace("Error occoured while loading the audio: The line is unavailable", e);
+      System.err.println("Error occoured while loading the audio: The line is unavailable");
+      e.printStackTrace();
     } catch (IOException e) {
-      LOGGER.trace("Input/Output error while loading the audio", e);
+      System.err.println("Input/Output error while loading the audio");
+      e.printStackTrace();
     } catch (IllegalArgumentException e) {
-      LOGGER.trace("The system doesn't support the sound: " + e.getMessage(), e);
+      System.err.println("The system doesn't support the sound: " + e.getMessage());
     }
   }
 
@@ -161,7 +153,7 @@ public class Audio {
    * @throws UnsupportedAudioFileException when the audio file is not supported 
    * @throws IOException when the file is not readable
    */
-  public AudioInputStream getAudioStream(String filePath)
+  public static AudioInputStream getAudioStream(String filePath) 
       throws UnsupportedAudioFileException, IOException {
     return AudioSystem.getAudioInputStream(new File(filePath).getAbsoluteFile());
   }
@@ -170,7 +162,7 @@ public class Audio {
    * Returns with the message array of the queue 
    * @return PlayMessage[]
    */
-  public PlayMessage[] getPendingAudio() {
+  public static PlayMessage[] getPendingAudio() {
     return pendingAudio;
   }
 

event-queue/src/test/java/com/iluwatar/event/queue/AudioTest.java

@@ -23,7 +23,6 @@
 
 package com.iluwatar.event.queue;
 
-import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
 import javax.sound.sampled.UnsupportedAudioFileException;
@@ -40,12 +39,6 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
  */
 public class AudioTest {
 
-  private Audio audio;
-
-  @BeforeEach
-  void createAudioInstance() {
-    audio = new Audio();
-  }
   /**
    * Test here that the playSound method works correctly
    * @throws UnsupportedAudioFileException when the audio file is not supported 
@@ -54,15 +47,13 @@ public class AudioTest {
    */
   @Test
   public void testPlaySound() throws UnsupportedAudioFileException, IOException, InterruptedException {
-    audio.playSound(audio.getAudioStream("./etc/Bass-Drum-1.wav"), -10.0f);
+    Audio.playSound(Audio.getAudioStream("./etc/Bass-Drum-1.wav"), -10.0f);
     // test that service is started
-    assertTrue(audio.isServiceRunning());
+    assertTrue(Audio.isServiceRunning());
     // adding a small pause to be sure that the sound is ended
     Thread.sleep(5000);
-
-    audio.stopService();
     // test that service is finished
-    assertFalse(audio.isServiceRunning());
+    assertFalse(!Audio.isServiceRunning());
   }
 
   /**
@@ -73,18 +64,16 @@ public class AudioTest {
    */
   @Test
   public void testQueue() throws UnsupportedAudioFileException, IOException, InterruptedException {
-    audio.playSound(audio.getAudioStream("./etc/Bass-Drum-1.aif"), -10.0f);
-    audio.playSound(audio.getAudioStream("./etc/Bass-Drum-1.aif"), -10.0f);
-    audio.playSound(audio.getAudioStream("./etc/Bass-Drum-1.aif"), -10.0f);
-    assertTrue(audio.getPendingAudio().length > 0);
+    Audio.playSound(Audio.getAudioStream("./etc/Bass-Drum-1.aif"), -10.0f);
+    Audio.playSound(Audio.getAudioStream("./etc/Bass-Drum-1.aif"), -10.0f);
+    Audio.playSound(Audio.getAudioStream("./etc/Bass-Drum-1.aif"), -10.0f);
+    assertTrue(Audio.getPendingAudio().length > 0);
     // test that service is started
-    assertTrue(audio.isServiceRunning());
+    assertTrue(Audio.isServiceRunning());
     // adding a small pause to be sure that the sound is ended
     Thread.sleep(10000);
-
-    audio.stopService();
     // test that service is finished
-    assertFalse(audio.isServiceRunning());
+    assertFalse(!Audio.isServiceRunning());
   }
 
 }

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

@@ -110,21 +110,6 @@ public class MongoTicketRepository implements LotteryTicketRepository {
     return result.getInteger("seq");
   }
 
-  /**
-   * @return mongo client
-   */
-  public MongoClient getMongoClient() {
-    return mongoClient;
-  }
-
-  /**
-   *
-   * @return mongo database
-   */
-  public MongoDatabase getMongoDatabase() {
-    return database;
-  }
-
   /**
    *
    * @return tickets collection

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

@@ -22,12 +22,13 @@
  */
 package com.iluwatar.hexagonal.domain;
 
+import com.google.common.base.Joiner;
+
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.PrimitiveIterator;
 import java.util.Random;
 import java.util.Set;
-import java.util.Iterator;
 
 /**
  *
@@ -84,15 +85,7 @@ public class LotteryNumbers {
    * @return numbers as comma separated string
    */
   public String getNumbersAsString() {
-    StringBuilder builder = new StringBuilder();
-    Iterator<Integer> iterator = numbers.iterator();
-    for (int i = 0; i < NUM_NUMBERS; i++) {
-      builder.append(iterator.next());
-      if (i < NUM_NUMBERS - 1) {
-        builder.append(",");
-      }
-    }
-    return builder.toString();
+    return Joiner.on(',').join(numbers);
   }
   
   /**

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

@@ -22,17 +22,18 @@
  */
 package com.iluwatar.hexagonal.domain;
 
+import java.util.concurrent.atomic.AtomicInteger;
+
 /**
  * Lottery ticked id
  */
 public class LotteryTicketId {
 
-  private static volatile int numAllocated;
+  private static AtomicInteger numAllocated = new AtomicInteger(0);
   private final int id;
   
   public LotteryTicketId() {
-    this.id = numAllocated + 1;
-    numAllocated++;
+    this.id = numAllocated.incrementAndGet();
   }
 
   public LotteryTicketId(int id) {

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

@@ -27,10 +27,10 @@ import org.junit.jupiter.api.Test;
 /**
  * Unit test for simple App.
  */
-public class AppTest {
+class AppTest {
 
   @Test
-  public void testApp() {
+  void testApp() {
     String[] args = {};
     App.main(args);
   }

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

@@ -32,19 +32,19 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
  * Tests for banking
  *
  */
-public class InMemoryBankTest {
+class InMemoryBankTest {
 
   private final WireTransfers bank = new InMemoryBank();
   
   @Test
-  public void testInit() {
-    assertEquals(bank.getFunds("foo"), 0);
+  void testInit() {
+    assertEquals(0, bank.getFunds("foo"));
     bank.setFunds("foo", 100);
-    assertEquals(bank.getFunds("foo"), 100);
+    assertEquals(100, bank.getFunds("foo"));
     bank.setFunds("bar", 150);
-    assertEquals(bank.getFunds("bar"), 150);
+    assertEquals(150, bank.getFunds("bar"));
     assertTrue(bank.transferFunds(50, "bar", "foo"));
-    assertEquals(bank.getFunds("foo"), 150);
-    assertEquals(bank.getFunds("bar"), 100);
+    assertEquals(150, bank.getFunds("foo"));
+    assertEquals(100, bank.getFunds("bar"));
   }
 }

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

@@ -34,7 +34,7 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
  * Tests for Mongo banking adapter
  */
 @Disabled
-public class MongoBankTest {
+class MongoBankTest {
 
   private static final String TEST_DB = "lotteryDBTest";
   private static final String TEST_ACCOUNTS_COLLECTION = "testAccounts";
@@ -42,7 +42,7 @@ public class MongoBankTest {
   private MongoBank mongoBank;
 
   @BeforeEach
-  public void init() {
+  void init() {
     MongoConnectionPropertiesLoader.load();
     MongoClient mongoClient = new MongoClient(System.getProperty("mongo-host"),
         Integer.parseInt(System.getProperty("mongo-port")));
@@ -52,12 +52,12 @@ public class MongoBankTest {
   }
 
   @Test
-  public void testSetup() {
+  void testSetup() {
     assertEquals(0, mongoBank.getAccountsCollection().count());
   }
 
   @Test
-  public void testFundTransfers() {
+  void testFundTransfers() {
     assertEquals(0, mongoBank.getFunds("000-000"));
     mongoBank.setFunds("000-000", 10);
     assertEquals(10, mongoBank.getFunds("000-000"));

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

@@ -38,23 +38,23 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
  * Tests for {@link LotteryTicketRepository}
  *
  */
-public class InMemoryTicketRepositoryTest {
+class InMemoryTicketRepositoryTest {
 
   private final LotteryTicketRepository repository = new InMemoryTicketRepository();
   
   @BeforeEach
-  public void clear() {
+  void clear() {
     repository.deleteAll();
   }
   
   @Test
-  public void testCrudOperations() {
+  void testCrudOperations() {
     LotteryTicketRepository repository = new InMemoryTicketRepository();
-    assertEquals(repository.findAll().size(), 0);
+    assertTrue(repository.findAll().isEmpty());
     LotteryTicket ticket = LotteryTestUtils.createLotteryTicket();
     Optional<LotteryTicketId> id = repository.save(ticket);
     assertTrue(id.isPresent());
-    assertEquals(repository.findAll().size(), 1);
+    assertEquals(1, repository.findAll().size());
     Optional<LotteryTicket> optionalTicket = repository.findById(id.get());
     assertTrue(optionalTicket.isPresent());
   }

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

@@ -41,7 +41,7 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
  * Tests for Mongo based ticket repository
  */
 @Disabled
-public class MongoTicketRepositoryTest {
+class MongoTicketRepositoryTest {
 
   private static final String TEST_DB = "lotteryTestDB";
   private static final String TEST_TICKETS_COLLECTION = "lotteryTestTickets";
@@ -50,7 +50,7 @@ public class MongoTicketRepositoryTest {
   private MongoTicketRepository repository;
 
   @BeforeEach
-  public void init() {
+  void init() {
     MongoConnectionPropertiesLoader.load();
     MongoClient mongoClient = new MongoClient(System.getProperty("mongo-host"),
         Integer.parseInt(System.getProperty("mongo-port")));
@@ -61,20 +61,20 @@ public class MongoTicketRepositoryTest {
   }
 
   @Test
-  public void testSetup() {
-    assertTrue(repository.getCountersCollection().count() == 1);
-    assertTrue(repository.getTicketsCollection().count() == 0);
+  void testSetup() {
+    assertEquals(1, repository.getCountersCollection().count());
+    assertEquals(0, repository.getTicketsCollection().count());
   }
 
   @Test
-  public void testNextId() {
+  void testNextId() {
     assertEquals(1, repository.getNextId());
     assertEquals(2, repository.getNextId());
     assertEquals(3, repository.getNextId());
   }
 
   @Test
-  public void testCrudOperations() {
+  void testCrudOperations() {
     // create new lottery ticket and save it
     PlayerDetails details = new PlayerDetails("foo@bar.com", "123-123", "07001234");
     LotteryNumbers random = LotteryNumbers.createRandom();

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

@@ -28,7 +28,7 @@ import java.util.Arrays;
 import java.util.HashSet;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
@@ -37,10 +37,10 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
  * Unit tests for {@link LotteryNumbers}
  *
  */
-public class LotteryNumbersTest {
+class LotteryNumbersTest {
   
   @Test
-  public void testGivenNumbers() {
+  void testGivenNumbers() {
     LotteryNumbers numbers = LotteryNumbers.create(
             new HashSet<>(Arrays.asList(1, 2, 3, 4)));
     assertEquals(numbers.getNumbers().size(), 4);
@@ -51,7 +51,7 @@ public class LotteryNumbersTest {
   }
   
   @Test
-  public void testNumbersCantBeModified() {
+  void testNumbersCantBeModified() {
     LotteryNumbers numbers = LotteryNumbers.create(
             new HashSet<>(Arrays.asList(1, 2, 3, 4)));
     assertThrows(UnsupportedOperationException.class, () -> {
@@ -60,20 +60,20 @@ public class LotteryNumbersTest {
   }
   
   @Test
-  public void testRandomNumbers() {
+  void testRandomNumbers() {
     LotteryNumbers numbers = LotteryNumbers.createRandom();
     assertEquals(numbers.getNumbers().size(), LotteryNumbers.NUM_NUMBERS);
   }
   
   @Test
-  public void testEquals() {
+  void testEquals() {
     LotteryNumbers numbers1 = LotteryNumbers.create(
             new HashSet<>(Arrays.asList(1, 2, 3, 4)));
     LotteryNumbers numbers2 = LotteryNumbers.create(
             new HashSet<>(Arrays.asList(1, 2, 3, 4)));
-    assertTrue(numbers1.equals(numbers2));
+    assertEquals(numbers1, numbers2);
     LotteryNumbers numbers3 = LotteryNumbers.create(
             new HashSet<>(Arrays.asList(11, 12, 13, 14)));
-    assertFalse(numbers1.equals(numbers3));
+    assertNotEquals(numbers1, numbers3);
   }
 }

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

@@ -38,6 +38,7 @@ import java.util.Map;
 import java.util.Optional;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 /**
@@ -45,7 +46,7 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
  * Test the lottery system
  *
  */
-public class LotteryTest {
+class LotteryTest {
 
   private Injector injector;
   @Inject
@@ -55,22 +56,22 @@ public class LotteryTest {
   @Inject
   private WireTransfers wireTransfers;
 
-  public LotteryTest() {
+  LotteryTest() {
     this.injector = Guice.createInjector(new LotteryTestingModule());
   }
 
   @BeforeEach
-  public void setup() {
+  void setup() {
     injector.injectMembers(this);
     // add funds to the test player's bank account
     wireTransfers.setFunds("123-12312", 100);
   }
   
   @Test
-  public void testLottery() {
+  void testLottery() {
     // admin resets the lottery
     administration.resetLottery();
-    assertEquals(administration.getAllSubmittedTickets().size(), 0);
+    assertEquals(0, administration.getAllSubmittedTickets().size());
     
     // players submit the lottery tickets
     Optional<LotteryTicketId> ticket1 = service.submitTicket(LotteryTestUtils.createLotteryTicket("cvt@bbb.com",
@@ -82,7 +83,7 @@ public class LotteryTest {
     Optional<LotteryTicketId> ticket3 = service.submitTicket(LotteryTestUtils.createLotteryTicket("arg@boo.com",
         "123-12312", "+32421255", new HashSet<>(Arrays.asList(6, 8, 13, 19))));
     assertTrue(ticket3.isPresent());
-    assertEquals(administration.getAllSubmittedTickets().size(), 3);
+    assertEquals(3, administration.getAllSubmittedTickets().size());
     
     // perform lottery
     LotteryNumbers winningNumbers = administration.performLottery();
@@ -91,23 +92,23 @@ public class LotteryTest {
     Optional<LotteryTicketId> ticket4 = service.submitTicket(LotteryTestUtils.createLotteryTicket("lucky@orb.com",
         "123-12312", "+12421255", winningNumbers.getNumbers()));
     assertTrue(ticket4.isPresent());
-    assertEquals(administration.getAllSubmittedTickets().size(), 4);
+    assertEquals(4, administration.getAllSubmittedTickets().size());
     
     // check winners
     Map<LotteryTicketId, LotteryTicket> tickets = administration.getAllSubmittedTickets();
     for (LotteryTicketId id: tickets.keySet()) {
       LotteryTicketCheckResult checkResult = service.checkTicketForPrize(id, winningNumbers);
-      assertTrue(checkResult.getResult() != CheckResult.TICKET_NOT_SUBMITTED);
+      assertNotEquals(CheckResult.TICKET_NOT_SUBMITTED, checkResult.getResult());
       if (checkResult.getResult().equals(CheckResult.WIN_PRIZE)) {
         assertTrue(checkResult.getPrizeAmount() > 0);
       } else if (checkResult.getResult().equals(CheckResult.WIN_PRIZE)) {
-        assertEquals(checkResult.getPrizeAmount(), 0);
+        assertEquals(0, checkResult.getPrizeAmount());
       }
     }
     
     // check another ticket that has not been submitted
     LotteryTicketCheckResult checkResult = service.checkTicketForPrize(new LotteryTicketId(), winningNumbers);
-    assertTrue(checkResult.getResult() == CheckResult.TICKET_NOT_SUBMITTED);
-    assertEquals(checkResult.getPrizeAmount(), 0);
+    assertEquals(CheckResult.TICKET_NOT_SUBMITTED, checkResult.getResult());
+    assertEquals(0, checkResult.getPrizeAmount());
   }
 }

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

@@ -26,21 +26,21 @@ 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.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
 
 /**
  * 
  * Unit tests for {@link LotteryTicketCheckResult}
  *
  */
-public class LotteryTicketCheckResultTest {
+class LotteryTicketCheckResultTest {
 
   @Test
-  public void testEquals() {
+  void testEquals() {
     LotteryTicketCheckResult result1 = new LotteryTicketCheckResult(CheckResult.NO_PRIZE);
     LotteryTicketCheckResult result2 = new LotteryTicketCheckResult(CheckResult.NO_PRIZE);
     assertEquals(result1, result2);
     LotteryTicketCheckResult result3 = new LotteryTicketCheckResult(CheckResult.WIN_PRIZE, 300000);
-    assertFalse(result1.equals(result3));
+    assertNotEquals(result1, result3);
   } 
 }

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

@@ -24,22 +24,22 @@ package com.iluwatar.hexagonal.domain;
 
 import org.junit.jupiter.api.Test;
 
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
 
 /**
  * Tests for lottery ticket id
  */
-public class LotteryTicketIdTest {
+class LotteryTicketIdTest {
 
   @Test
-  public void testEquals() {
+  void testEquals() {
     LotteryTicketId ticketId1 = new LotteryTicketId();
     LotteryTicketId ticketId2 = new LotteryTicketId();
     LotteryTicketId ticketId3 = new LotteryTicketId();
-    assertFalse(ticketId1.equals(ticketId2));
-    assertFalse(ticketId2.equals(ticketId3));
+    assertNotEquals(ticketId1, ticketId2);
+    assertNotEquals(ticketId2, ticketId3);
     LotteryTicketId ticketId4 = new LotteryTicketId(ticketId1.getId());
-    assertTrue(ticketId1.equals(ticketId4));
+    assertEquals(ticketId1, ticketId4);
   }
 }

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

@@ -29,14 +29,15 @@ import java.util.HashSet;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
 
 /**
  * Test Lottery Tickets for equality
  */
-public class LotteryTicketTest {
+class LotteryTicketTest {
 
   @Test
-  public void testEquals() {
+  void testEquals() {
     PlayerDetails details1 = new PlayerDetails("bob@foo.bar", "1212-121212", "+34332322");
     LotteryNumbers numbers1 = LotteryNumbers.create(new HashSet<Integer>(Arrays.asList(1, 2, 3, 4)));
     LotteryTicket ticket1 = new LotteryTicket(new LotteryTicketId(), details1, numbers1);
@@ -47,6 +48,6 @@ public class LotteryTicketTest {
     PlayerDetails details3 = new PlayerDetails("elsa@foo.bar", "1223-121212", "+49332322");
     LotteryNumbers numbers3 = LotteryNumbers.create(new HashSet<Integer>(Arrays.asList(1, 2, 3, 8)));
     LotteryTicket ticket3 = new LotteryTicket(new LotteryTicketId(), details3, numbers3);
-    assertFalse(ticket1.equals(ticket3));
+    assertNotEquals(ticket1, ticket3);
   }
 }

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

@@ -25,21 +25,21 @@ 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.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
 
 /**
  * 
  * Unit tests for {@link PlayerDetails}
  *
  */
-public class PlayerDetailsTest {
+class PlayerDetailsTest {
 
   @Test
-  public void testEquals() {
+  void testEquals() {
     PlayerDetails details1 = new PlayerDetails("tom@foo.bar", "11212-123434", "+12323425");
     PlayerDetails details2 = new PlayerDetails("tom@foo.bar", "11212-123434", "+12323425");
     assertEquals(details1, details2);
     PlayerDetails details3 = new PlayerDetails("john@foo.bar", "16412-123439", "+34323432");
-    assertFalse(details1.equals(details3));
+    assertNotEquals(details1, details3);
   }  
 }

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

@@ -35,7 +35,7 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
  * Tests for Mongo event log
  */
 @Disabled
-public class MongoEventLogTest {
+class MongoEventLogTest {
 
   private static final String TEST_DB = "lotteryDBTest";
   private static final String TEST_EVENTS_COLLECTION = "testEvents";
@@ -43,7 +43,7 @@ public class MongoEventLogTest {
   private MongoEventLog mongoEventLog;
 
   @BeforeEach
-  public void init() {
+  void init() {
     MongoConnectionPropertiesLoader.load();
     MongoClient mongoClient = new MongoClient(System.getProperty("mongo-host"),
         Integer.parseInt(System.getProperty("mongo-port")));
@@ -53,12 +53,12 @@ public class MongoEventLogTest {
   }
 
   @Test
-  public void testSetup() {
+  void testSetup() {
     assertEquals(0, mongoEventLog.getEventsCollection().count());
   }
 
   @Test
-  public void testFundTransfers() {
+  void testFundTransfers() {
     PlayerDetails playerDetails = new PlayerDetails("john@wayne.com", "000-000", "03432534543");
     mongoEventLog.prizeError(playerDetails, 1000);
     assertEquals(1, mongoEventLog.getEventsCollection().count());