A number of code style improvments

Mainly Sonar related issues.

source/taskmanager-client/src/main/java/nl/aerius/taskmanager/client/BrokerConnectionFactory.java

@@ -104,7 +104,7 @@ private Connection openConnection() {
         delayRetry(retryTime);
       }
     }
-    localConnection.addShutdownListener((cause) -> {
+    localConnection.addShutdownListener(cause -> {
       if (cause.isInitiatedByApplication()) {
         LOG.info("Connection was shut down (by application)");
       } else {
@@ -114,7 +114,7 @@ private Connection openConnection() {
     return localConnection;
   }
 
-  private void delayRetry(final int retryTime) {
+  private static void delayRetry(final int retryTime) {
     try {
       Thread.sleep(TimeUnit.SECONDS.toMillis(retryTime));
     } catch (final InterruptedException ex) {

source/taskmanager-client/src/main/java/nl/aerius/taskmanager/client/TaskManagerClientSender.java

@@ -46,10 +46,6 @@ public class TaskManagerClientSender implements TaskWrapperSender {
 
   private static final Logger LOG = LoggerFactory.getLogger(TaskManagerClientSender.class);
 
-  private static final boolean QUEUE_DURABLE = true;
-  private static final boolean QUEUE_EXCLUSIVE = false;
-  private static final boolean QUEUE_AUTO_DELETE = false;
-
   private static final int DELIVERY_MODE_NON_PERSISTENT = 1;
   private static final int DELIVERY_MODE_PERSISTENT = 2;
 

source/taskmanager-client/src/main/java/nl/aerius/taskmanager/client/configuration/ConnectionConfiguration.java

@@ -227,15 +227,15 @@ public ConnectionConfiguration build() {
       return connectionConfiguration;
     }
 
-    private void checkBlank(final String name, final String value) {
+    private static void checkBlank(final String name, final String value) {
       if (value == null || value.isEmpty()) {
         throw new IllegalArgumentException(name + " not allowed to be null or empty.");
       }
     }
 
     public ConnectionConfiguration.Builder brokerHost(final String brokerHost) {
       if (brokerHost == null) {
-        throw new NullPointerException("Null brokerHost");
+        throw new IllegalArgumentException("brokerHost null");
       }
       this.brokerHost = brokerHost;
       return this;
@@ -248,23 +248,23 @@ public ConnectionConfiguration.Builder brokerPort(final int brokerPort) {
 
     public ConnectionConfiguration.Builder brokerUsername(final String brokerUsername) {
       if (brokerUsername == null) {
-        throw new NullPointerException("Null brokerUsername");
+        throw new IllegalArgumentException("brokerUsername null");
       }
       this.brokerUsername = brokerUsername;
       return this;
     }
 
     public ConnectionConfiguration.Builder brokerPassword(final String brokerPassword) {
       if (brokerPassword == null) {
-        throw new NullPointerException("Null brokerPassword");
+        throw new IllegalArgumentException("brokerPassword null");
       }
       this.brokerPassword = brokerPassword;
       return this;
     }
 
     public ConnectionConfiguration.Builder brokerVirtualHost(final String brokerVirtualHost) {
       if (brokerVirtualHost == null) {
-        throw new NullPointerException("Null brokerVirtualHost");
+        throw new IllegalArgumentException("brokerVirtualHost null");
       }
       this.brokerVirtualHost = brokerVirtualHost;
       return this;

source/taskmanager-client/src/main/java/nl/aerius/taskmanager/client/mq/RabbitMQWorkerMonitor.java

@@ -192,7 +192,7 @@ private void handleDelivery(final AMQP.BasicProperties properties) {
    * @param param param to return the value for
    * @return value of param or null if not present
    */
-  private String getParam(final Map<String, Object> headers, final String param) {
+  private static String getParam(final Map<String, Object> headers, final String param) {
     final Object value = headers.get(param);
 
     return value == null ? null : value.toString();
@@ -206,7 +206,7 @@ private String getParam(final Map<String, Object> headers, final String param) {
    * @param other if param is not present this value is returned
    * @return int value of param or other if not present
    */
-  private int getParamInt(final Map<String, Object> headers, final String param, final int other) {
+  private static int getParamInt(final Map<String, Object> headers, final String param, final int other) {
     final String value = getParam(headers, param);
 
     try {

source/taskmanager-client/src/main/java/nl/aerius/taskmanager/client/util/QueueHelper.java

@@ -26,7 +26,7 @@
 import java.util.zip.GZIPInputStream;
 import java.util.zip.GZIPOutputStream;
 
-import com.rabbitmq.client.AMQP.BasicProperties;
+import com.rabbitmq.client.BasicProperties;
 import com.rabbitmq.client.LongString;
 
 /**

source/taskmanager-client/src/test/java/nl/aerius/taskmanager/client/BrokerConnectionFactoryTest.java

@@ -18,7 +18,6 @@
 
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
-import java.io.IOException;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 
@@ -46,7 +45,7 @@ static void afterClass() {
   }
 
   @Test
-  void testTaskManagerClientWithoutBrokerHost() throws IOException {
+  void testTaskManagerClientWithoutBrokerHost() {
     assertThrows(NullPointerException.class, () -> {
       final ConnectionConfiguration.Builder builder = getFullConnectionConfigurationBuilder();
       builder.brokerHost(null);
@@ -55,7 +54,7 @@ void testTaskManagerClientWithoutBrokerHost() throws IOException {
   }
 
   @Test
-  void testTaskManagerClientWithEmptyBrokerHost() throws IOException {
+  void testTaskManagerClientWithEmptyBrokerHost() {
     assertThrows(IllegalArgumentException.class, () -> {
       final ConnectionConfiguration.Builder builder = getFullConnectionConfigurationBuilder();
       builder.brokerHost("");
@@ -64,7 +63,7 @@ void testTaskManagerClientWithEmptyBrokerHost() throws IOException {
   }
 
   @Test
-  void testTaskManagerClientWithoutBrokerUsername() throws IOException {
+  void testTaskManagerClientWithoutBrokerUsername() {
     assertThrows(NullPointerException.class, () -> {
       final ConnectionConfiguration.Builder builder = getFullConnectionConfigurationBuilder();
       builder.brokerUsername(null);
@@ -73,7 +72,7 @@ void testTaskManagerClientWithoutBrokerUsername() throws IOException {
   }
 
   @Test
-  void testTaskManagerClientWithEmptyBrokerUsername() throws IOException {
+  void testTaskManagerClientWithEmptyBrokerUsername() {
     assertThrows(IllegalArgumentException.class, () -> {
       final ConnectionConfiguration.Builder builder = getFullConnectionConfigurationBuilder();
       builder.brokerUsername("");
@@ -82,7 +81,7 @@ void testTaskManagerClientWithEmptyBrokerUsername() throws IOException {
   }
 
   @Test
-  void testTaskManagerClientWithoutBrokerPassword() throws IOException {
+  void testTaskManagerClientWithoutBrokerPassword() {
     assertThrows(NullPointerException.class, () -> {
       final ConnectionConfiguration.Builder builder = getFullConnectionConfigurationBuilder();
       builder.brokerPassword(null);
@@ -91,7 +90,7 @@ void testTaskManagerClientWithoutBrokerPassword() throws IOException {
   }
 
   @Test
-  void testTaskManagerClientWithEmptyBrokerPassword() throws IOException {
+  void testTaskManagerClientWithEmptyBrokerPassword() {
     assertThrows(IllegalArgumentException.class, () -> {
       final ConnectionConfiguration.Builder builder = getFullConnectionConfigurationBuilder();
       builder.brokerPassword("");
@@ -100,7 +99,7 @@ void testTaskManagerClientWithEmptyBrokerPassword() throws IOException {
   }
 
   @Test
-  void testTaskManagerClientWithoutBrokerVirtualHost() throws IOException {
+  void testTaskManagerClientWithoutBrokerVirtualHost() {
     assertThrows(NullPointerException.class, () -> {
       final ConnectionConfiguration.Builder builder = getFullConnectionConfigurationBuilder();
       builder.brokerVirtualHost(null);
@@ -109,7 +108,7 @@ void testTaskManagerClientWithoutBrokerVirtualHost() throws IOException {
   }
 
   @Test
-  void testTaskManagerClientWithEmptyBrokerVirtualHost() throws IOException {
+  void testTaskManagerClientWithEmptyBrokerVirtualHost() {
     assertThrows(IllegalArgumentException.class, () -> {
       final ConnectionConfiguration.Builder builder = getFullConnectionConfigurationBuilder();
       builder.brokerVirtualHost("");

source/taskmanager-client/src/test/java/nl/aerius/taskmanager/client/MockTaskResultHandler.java

@@ -21,10 +21,8 @@
 import java.util.concurrent.Semaphore;
 import java.util.concurrent.TimeUnit;
 
-import nl.aerius.taskmanager.client.TaskResultCallback;
-
 /**
- *
+ * Util class to more easily mock a {@link TaskResultCallback}.
  */
 class MockTaskResultHandler implements TaskResultCallback {
 

source/taskmanager-client/src/test/java/nl/aerius/taskmanager/client/TaskManagerClientTest.java

@@ -48,26 +48,26 @@ class TaskManagerClientTest {
   private static final WorkerQueueType WORKER_TYPE_TEST = new WorkerQueueType("TEST");
   private static final String NORMAL_TASK_ID = "SomeTaskId";
   private static final String TASK_QUEUE_NAME = "taskmanagerclienttest.task";
-  private static ExecutorService EXECUTOR;
+  private static ExecutorService executor;
   private WorkerQueueType workerType;
   private TaskManagerClientSender taskManagerClient;
   private MockTaskResultHandler mockTaskResultHandler;
 
   @BeforeAll
   static void setupClass() {
-    EXECUTOR = Executors.newSingleThreadExecutor();
+    executor = Executors.newSingleThreadExecutor();
   }
 
   @AfterAll
   static void afterClass() {
-    EXECUTOR.shutdown();
+    executor.shutdown();
   }
 
   @BeforeEach
-  void setUp() throws Exception {
+  void setUp() {
     mockTaskResultHandler = new MockTaskResultHandler();
     workerType = WORKER_TYPE_TEST;
-    taskManagerClient = new TaskManagerClientSender(new BrokerConnectionFactory(EXECUTOR) {
+    taskManagerClient = new TaskManagerClientSender(new BrokerConnectionFactory(executor) {
       @Override
       protected Connection createNewConnection() throws IOException {
         return new MockConnection();
@@ -76,7 +76,7 @@ protected Connection createNewConnection() throws IOException {
   }
 
   @AfterEach
-  void tearDown() throws Exception {
+  void tearDown() {
     taskManagerClient.shutdown();
   }
 
@@ -104,7 +104,7 @@ void testSendTasks() throws IOException {
   }
 
   @Test
-  void testSendTasksWithNullId() throws IOException, InterruptedException {
+  void testSendTasksWithNullId() throws IOException {
     taskManagerClient.sendTask(new MockTaskInput(), null, mockTaskResultHandler, workerType, TASK_QUEUE_NAME);
     assertTrue(taskManagerClient.isUsable(), "Taskmanagerclient should still be usable.");
   }
@@ -131,7 +131,7 @@ void testTaskManagerClientWithConnectionConfigurationBean() throws IOException,
    * @throws InterruptedException
    */
   @Test
-  void testSendUnserializableTask() throws IOException, InterruptedException {
+  void testSendUnserializableTask() {
     assertThrows(NotSerializableException.class, () -> {
       //anonymous inner type isn't serializable (even if the type is Serializable).
       final Serializable input = new Serializable() {
@@ -158,7 +158,7 @@ void testExit() throws IOException, InterruptedException {
    * @throws InterruptedException
    */
   @Test
-  void testSendTaskAfterExit() throws IOException, InterruptedException {
+  void testSendTaskAfterExit() {
     assertThrows(IllegalStateException.class, () -> {
       taskManagerClient.shutdown();
       testSendTask();
@@ -169,7 +169,7 @@ void testSendTaskAfterExit() throws IOException, InterruptedException {
    * Test method for {@link TaskManagerClientSender#sendTask(Object, String, String)}.
    */
   @Test
-  void testSendTaskToNullQueue() throws IOException {
+  void testSendTaskToNullQueue() {
     assertThrows(IllegalArgumentException.class,
         () -> taskManagerClient.sendTask(new MockTaskInput(), NORMAL_TASK_ID, mockTaskResultHandler, workerType, null));
   }
@@ -178,7 +178,7 @@ void testSendTaskToNullQueue() throws IOException {
    * Test method for {@link TaskManagerClientSender#sendTask(Object, String, String)}.
    */
   @Test
-  void testSendNullObjectAsTask() throws IOException {
+  void testSendNullObjectAsTask() {
     assertThrows(IllegalArgumentException.class, () -> taskManagerClient.sendTask(null, null, mockTaskResultHandler, workerType, TASK_QUEUE_NAME));
   }
 

source/taskmanager-test/src/main/java/nl/aerius/taskmanager/test/MockedChannelFactory.java

@@ -51,13 +51,17 @@
  *
  * This class keeps some state
  */
-public class MockedChannelFactory {
+public final class MockedChannelFactory {
 
   private static final ExecutorService EXECUTOR = Executors.newCachedThreadPool();
   private static final Map<String, PriorityBlockingQueue<Body>> QUEUES = new ConcurrentHashMap<>();
   private static final Map<Long, Body> QUEUED = new ConcurrentHashMap<>();
   private static byte[] received;
 
+  private MockedChannelFactory() {
+    // Util class
+  }
+
   /**
    * Creates a new mocked channel.
    *

source/taskmanager/src/main/java/nl/aerius/taskmanager/ConfigurationManager.java

@@ -35,7 +35,7 @@
  */
 final class ConfigurationManager {
 
-  private static final Logger LOG = LoggerFactory.getLogger(TaskManagerConfiguration.class);
+  private static final Logger LOG = LoggerFactory.getLogger(ConfigurationManager.class);
 
   private ConfigurationManager() {
   }

source/taskmanager/src/main/java/nl/aerius/taskmanager/FIFOTaskScheduler.java

@@ -27,7 +27,7 @@
  */
 class FIFOTaskScheduler implements TaskScheduler<PriorityTaskQueue> {
 
-  private final BlockingQueue<Task> tasks = new LinkedBlockingQueue<Task>();
+  private final BlockingQueue<Task> tasks = new LinkedBlockingQueue<>();
 
   @Override
   public void addTask(final Task task) {

source/taskmanager/src/main/java/nl/aerius/taskmanager/mq/RabbitMQQueueMonitor.java

@@ -107,7 +107,7 @@ public void updateWorkerQueueState(final String queueName, final WorkerSizeObser
     // Use RabbitMQ HTTP-API.
     // URL: [host]:[port]/api/queues/[virtualHost]/[QueueName]
     final String virtualHost = configuration.getBrokerVirtualHost().replace("/", "%2f");
-    final String apiPath = "/api/queues/" + virtualHost + "/" + queueName;
+    final String apiPath = String.format("/api/queues/%s/%s", virtualHost, queueName);
 
     try {
       final JsonNode jsonObject = getJsonResultFromApi(apiPath);

source/taskmanager/src/test/java/nl/aerius/taskmanager/ConfigurationManagerTest.java

@@ -42,7 +42,7 @@ void before() throws IOException {
 
   @Test
   @Timeout(2000)
-  void testLoadConfiguration() throws IOException {
+  void testLoadConfiguration() {
     final TaskManagerConfiguration tmc = ConfigurationManager.loadConfiguration(properties);
 
     assertNotNull(tmc.getBrokerConfiguration().getBrokerUsername(), "No username could be read from configuration file");

source/taskmanager/src/test/java/nl/aerius/taskmanager/PriorityTaskSchedulerTest.java

@@ -184,7 +184,7 @@ void testGetTask() throws InterruptedException, ExecutionException {
     assertEquals(0, chkCounter.intValue(), "Counter should still be zero when 1 slot priorty available");
     assertFalse(receivedTask.isDone(), "Should not be done yet");
     scheduler.onTaskFinished(task1a.getMessage().getMetaData().getQueueName());
-    await().atMost(1, TimeUnit.SECONDS).until(() -> receivedTask.isDone());
+    await().atMost(1, TimeUnit.SECONDS).until(receivedTask::isDone);
     assertNotNull(receivedTask.get(), "Received task");
     // task1a finished, now task1b may be executed.
     assertEquals(1, chkCounter.intValue(), "Counter should still be 1");

source/taskmanager/src/test/java/nl/aerius/taskmanager/QueueWatchDogTest.java

@@ -30,7 +30,7 @@
 class QueueWatchDogTest {
 
   @Test
-  void testIsItDead() throws InterruptedException {
+  void testIsItDead() {
     final AtomicReference<LocalDateTime> now = new AtomicReference<>(LocalDateTime.now());
     final QueueWatchDog qwd = new QueueWatchDog() {
       @Override

source/taskmanager/src/test/java/nl/aerius/taskmanager/TaskDispatcherTest.java

@@ -71,7 +71,7 @@ void after() throws InterruptedException {
 
   @Test
   @Timeout(3000)
-  void testNoFreeWorkers() throws InterruptedException {
+  void testNoFreeWorkers() {
     // Add Worker which will unlock
     workerPool.onNumberOfWorkersUpdate(1, 0);
     executor.execute(dispatcher);
@@ -89,21 +89,21 @@ void testNoFreeWorkers() throws InterruptedException {
 
   @Test
   @Timeout(3000)
-  void testForwardTest() throws InterruptedException {
+  void testForwardTest() {
     final Task task = createTask();
     final Future<?> future = forwardTaskAsync(task, null);
     executor.execute(dispatcher);
     await().until(() -> dispatcher.isLocked(task));
     workerPool.onNumberOfWorkersUpdate(1, 0); //add worker which will unlock
     await().until(() -> dispatcher.getState() == State.WAIT_FOR_WORKER);
-    await().until(() -> future.isDone());
+    await().until(future::isDone);
     assertFalse(future.isCancelled(), "Taskconsumer must be unlocked at this point without error");
   }
 
   @Disabled("TaskAlreadySendexception error willl not be thrown")
   @Test
   @Timeout(3000)
-  void testForwardDuplicateTask() throws InterruptedException {
+  void testForwardDuplicateTask() {
     final Task task = createTask();
     executor.execute(dispatcher);
     final Future<?> future = forwardTaskAsync(task, null);
@@ -124,7 +124,7 @@ void testForwardDuplicateTask() throws InterruptedException {
 
   @Test
   @Timeout(3000)
-  void testExceptionDuringForward() throws InterruptedException {
+  void testExceptionDuringForward() {
     workerProducer.setShutdownExceptionOnForward(true);
     final Task task = createTask();
     executor.execute(dispatcher);