Cleanup code smells reported by Sonar

This is a first pass are removing some of the code smells.
Many reported code smells were ignored in this effort

spring-cloud-task-core/src/main/java/org/springframework/cloud/task/configuration/SingleInstanceTaskListener.java

@@ -49,7 +49,7 @@ import org.springframework.integration.support.locks.LockRegistry;
  */
 public class SingleInstanceTaskListener implements ApplicationListener<ApplicationEvent> {
 
-	private final static Log logger = LogFactory.getLog(SingleInstanceTaskListener.class);
+	private static final Log logger = LogFactory.getLog(SingleInstanceTaskListener.class);
 
 	private LockRegistry lockRegistry;
 

spring-cloud-task-core/src/main/java/org/springframework/cloud/task/configuration/SingleTaskConfiguration.java

@@ -16,21 +16,15 @@
 
 package org.springframework.cloud.task.configuration;
 
-import java.util.Collection;
-
-import javax.sql.DataSource;
-
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.cloud.task.repository.support.SimpleTaskNameResolver;
 import org.springframework.context.ApplicationEventPublisher;
-import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.Ordered;
 import org.springframework.core.annotation.Order;
 import org.springframework.integration.support.locks.PassThruLockRegistry;
-import org.springframework.util.CollectionUtils;
 
 /**
  * Autoconfiguration of {@link SingleInstanceTaskListener}.

spring-cloud-task-core/src/main/java/org/springframework/cloud/task/configuration/TaskProperties.java

@@ -31,6 +31,9 @@ import org.springframework.boot.context.properties.ConfigurationProperties;
 
 @ConfigurationProperties(prefix = "spring.cloud.task")
 public class TaskProperties {
+
+	private static final int DEFAULT_CHECK_INTERVAL = 500;
+
 	private static final Log logger = LogFactory.getLog(TaskProperties.class);
 	
 	public static final String DEFAULT_TABLE_PREFIX = "TASK_";
@@ -82,7 +85,7 @@ public class TaskProperties {
 	 * Declares the  time (in millis) that a task execution will wait between
 	 * checks. Default time is: 500 millis.
 	 */
-	private int singleInstanceLockCheckInterval = 500;
+	private int singleInstanceLockCheckInterval = DEFAULT_CHECK_INTERVAL;
 
 	public String getExternalExecutionId() {
 		return externalExecutionId;

spring-cloud-task-core/src/main/java/org/springframework/cloud/task/listener/TaskExecutionListener.java

@@ -29,14 +29,14 @@ public interface TaskExecutionListener {
 	 * Invoked after the {@link TaskExecution} has been stored in the {@link TaskRepository}.
 	 * @param taskExecution instance containing the information about the current task.
 	 */
-	public void onTaskStartup(TaskExecution taskExecution);
+	void onTaskStartup(TaskExecution taskExecution);
 
 	/**
 	 * Invoked before the {@link TaskExecution} has been updated in the {@link TaskRepository}
 	 * upon task end.
 	 * @param taskExecution instance containing the information about the current task.
 	 */
-	public void onTaskEnd(TaskExecution taskExecution);
+	void onTaskEnd(TaskExecution taskExecution);
 
 	/**
 	 * Invoked if an uncaught exception occurs during a task execution.  This invocation
@@ -45,5 +45,5 @@ public interface TaskExecutionListener {
 	 * @param taskExecution instance containing the information about the current task.
 	 * @param throwable the uncaught exception that was thrown during task execution.
 	 */
-	public void onTaskFailed(TaskExecution taskExecution, Throwable throwable);
+	void onTaskFailed(TaskExecution taskExecution, Throwable throwable);
 }

spring-cloud-task-core/src/main/java/org/springframework/cloud/task/listener/TaskLifecycleListener.java

@@ -85,7 +85,7 @@ public class TaskLifecycleListener implements ApplicationListener<ApplicationEve
 
 	private List<TaskExecutionListener> taskExecutionListeners;
 
-	private final static Log logger = LogFactory.getLog(TaskLifecycleListener.class);
+	private static final  Log logger = LogFactory.getLog(TaskLifecycleListener.class);
 
 	private final TaskRepository taskRepository;
 

spring-cloud-task-core/src/main/java/org/springframework/cloud/task/listener/TaskListenerExecutorObjectFactory.java

@@ -49,7 +49,7 @@ import org.springframework.core.annotation.AnnotationUtils;
  */
 public class TaskListenerExecutorObjectFactory implements ObjectFactory<TaskExecutionListener> {
 
-	private final static Log logger = LogFactory.getLog(TaskListenerExecutor.class);
+	private static final Log logger = LogFactory.getLog(TaskListenerExecutor.class);
 
 	private final Set<Class<?>> nonAnnotatedClasses =
 			Collections.newSetFromMap(new ConcurrentHashMap<>());

spring-cloud-task-core/src/main/java/org/springframework/cloud/task/repository/dao/JdbcTaskExecutionDao.java

@@ -46,7 +46,6 @@ import org.springframework.jdbc.core.RowCallbackHandler;
 import org.springframework.jdbc.core.RowMapper;
 import org.springframework.jdbc.core.namedparam.MapSqlParameterSource;
 import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
-import org.springframework.jdbc.core.namedparam.SqlParameterSource;
 import org.springframework.jdbc.support.incrementer.DataFieldMaxValueIncrementer;
 import org.springframework.util.Assert;
 import org.springframework.util.CollectionUtils;
@@ -568,7 +567,7 @@ public class JdbcTaskExecutionDao implements TaskExecutionDao {
 	 */
 	private final class TaskExecutionRowMapper implements RowMapper<TaskExecution> {
 
-		public TaskExecutionRowMapper() {
+		private TaskExecutionRowMapper() {
 		}
 
 		@Override

spring-cloud-task-core/src/main/java/org/springframework/cloud/task/repository/dao/MapTaskExecutionDao.java

@@ -16,6 +16,7 @@
 
 package org.springframework.cloud.task.repository.dao;
 
+import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;
@@ -322,7 +323,7 @@ public class MapTaskExecutionDao implements TaskExecutionDao {
 		}
 	}
 
-	private static class TaskExecutionComparator implements Comparator<TaskExecution> {
+	private static class TaskExecutionComparator implements Comparator<TaskExecution>, Serializable {
 		@Override
 		public int compare(TaskExecution firstTaskExecution, TaskExecution secondTaskExecution) {
 			if (firstTaskExecution.getStartTime().equals(secondTaskExecution.getStartTime())) {

spring-cloud-task-core/src/main/java/org/springframework/cloud/task/repository/support/DatabaseType.java

@@ -50,7 +50,7 @@ public enum DatabaseType {
 
 	private final String productName;
 
-	private DatabaseType(String productName) {
+	DatabaseType(String productName) {
 		this.productName = productName;
 	}
 

spring-cloud-task-core/src/main/java/org/springframework/cloud/task/repository/support/SimpleTaskRepository.java

@@ -39,7 +39,7 @@ public class SimpleTaskRepository implements TaskRepository {
 	public static final int MAX_TASK_NAME_SIZE = 100;
 	public static final int MAX_ERROR_MESSAGE_SIZE = 2500;
 
-	private final static Log logger = LogFactory.getLog(SimpleTaskRepository.class);
+	private static final  Log logger = LogFactory.getLog(SimpleTaskRepository.class);
 
 	private TaskExecutionDao taskExecutionDao;