TSK-726 Refactored public api and history event producer to initialize TaskanaHistory implementations

lib/taskana-core/src/main/java/pro/taskana/history/HistoryEventProducer.java

@@ -6,6 +6,7 @@ import java.util.ServiceLoader;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import pro.taskana.configuration.TaskanaEngineConfiguration;
 import pro.taskana.history.api.TaskanaHistory;
 import pro.taskana.history.api.TaskanaHistoryEvent;
 
@@ -16,26 +17,30 @@ public final class HistoryEventProducer {
 
     private static final Logger LOGGER = LoggerFactory.getLogger(HistoryEventProducer.class);
 
+    TaskanaEngineConfiguration taskanaEngineConfiguration;
     private static HistoryEventProducer emitterInstance;
     private ServiceLoader<TaskanaHistory> serviceLoader;
     private boolean enabled = false;
 
-    public static synchronized HistoryEventProducer getInstance() {
+
+    public static synchronized HistoryEventProducer getInstance(TaskanaEngineConfiguration taskanaEngineConfiguration) {
         if (emitterInstance == null) {
-            emitterInstance = new HistoryEventProducer();
+            emitterInstance = new HistoryEventProducer(taskanaEngineConfiguration);
         }
         return emitterInstance;
     }
 
     public static boolean isHistoryEnabled() {
-        return getInstance().isEnabled();
+        return getInstance(null).isEnabled();
     }
 
-    private HistoryEventProducer() {
+    private HistoryEventProducer(TaskanaEngineConfiguration taskanaEngineConfiguration) {
+        this.taskanaEngineConfiguration = taskanaEngineConfiguration;
         serviceLoader = ServiceLoader.load(TaskanaHistory.class);
         Iterator<TaskanaHistory> serviceIterator = serviceLoader.iterator();
         while (serviceIterator.hasNext()) {
             TaskanaHistory history = serviceIterator.next();
+            history.initialize(taskanaEngineConfiguration);
             LOGGER.info("Registered history provider: {}", history.getClass().getName());
             enabled = true;
         }

lib/taskana-core/src/main/java/pro/taskana/history/api/TaskanaHistory.java

@@ -1,10 +1,20 @@
 package pro.taskana.history.api;
 
+import pro.taskana.configuration.TaskanaEngineConfiguration;
+
 /**
  * Interface for TASKANA History Service Provider.
  */
 public interface TaskanaHistory {
 
+    /**
+     * Initialize TaskanaHistory service.
+     *
+     * @param  taskanaEngineConfiguration
+     *            {@link TaskanaEngineConfiguration} The Taskana engine configuration for needed initialization.
+     */
+    void initialize(TaskanaEngineConfiguration taskanaEngineConfiguration);
+
     /**
      * Create a new history event.
      *

lib/taskana-core/src/main/java/pro/taskana/history/api/TaskanaHistoryEvent.java

@@ -9,7 +9,7 @@ import pro.taskana.security.CurrentUserContext;
  */
 public class TaskanaHistoryEvent {
 
-    protected long id;
+    protected String id;
     protected String type;
     protected String userId;
     protected Instant created;
@@ -19,11 +19,11 @@ public class TaskanaHistoryEvent {
         userId = CurrentUserContext.getUserid();
     }
 
-    public long getId() {
+    public String getId() {
         return id;
     }
 
-    public void setId(long id) {
+    public void setId(String id) {
         this.id = id;
     }
 

lib/taskana-core/src/main/java/pro/taskana/impl/TaskanaEngineImpl.java

@@ -68,7 +68,7 @@ public class TaskanaEngineImpl implements TaskanaEngine {
         this.taskanaEngineConfiguration = taskanaEngineConfiguration;
         createTransactionFactory(taskanaEngineConfiguration.getUseManagedTransactions());
         this.sessionManager = createSqlSessionManager();
-        this.historyEventProducer = HistoryEventProducer.getInstance();
+        this.historyEventProducer = HistoryEventProducer.getInstance(taskanaEngineConfiguration);
     }
 
     public static TaskanaEngine createTaskanaEngine(TaskanaEngineConfiguration taskanaEngineConfiguration) {

lib/taskana-spring-example/src/main/java/pro/taskana/TaskanaConfig.java

@@ -15,10 +15,6 @@ import org.springframework.context.annotation.PropertySource;
 import org.springframework.jdbc.datasource.DataSourceTransactionManager;
 import org.springframework.transaction.annotation.EnableTransactionManagement;
 
-import pro.taskana.ClassificationService;
-import pro.taskana.TaskService;
-import pro.taskana.TaskanaEngine;
-import pro.taskana.WorkbasketService;
 import pro.taskana.configuration.SpringTaskanaEngineConfiguration;
 
 /**
@@ -93,6 +89,6 @@ public class TaskanaConfig {
 
     @Bean
     public ExampleBootstrap exampleBootstrap() {
-      return new ExampleBootstrap() ;
+        return new ExampleBootstrap();
     }
 }