TSK-967: Refactor the DBCleaner

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

@@ -1198,6 +1198,8 @@ public class TaskServiceImpl implements TaskService {
         PrioDurationHolder prioDurationFromAttachments)
             throws InvalidArgumentException, ConcurrencyException, ClassificationNotFoundException {
         validateObjectReference(newTaskImpl.getPrimaryObjRef(), "primary ObjectReference", "Task");
+        //TODO: not safe to rely only on different timestamps.
+        // With fast execution below 1ms there will be no concurrencyException
         if (oldTaskImpl.getModified() != null && !oldTaskImpl.getModified().equals(newTaskImpl.getModified())
             || oldTaskImpl.getClaimed() != null && !oldTaskImpl.getClaimed().equals(newTaskImpl.getClaimed())
             || oldTaskImpl.getState() != null && !oldTaskImpl.getState().equals(newTaskImpl.getState())) {

lib/taskana-core/src/test/java/acceptance/AbstractAccTest.java

@@ -24,7 +24,6 @@ import pro.taskana.TimeInterval;
 import pro.taskana.configuration.TaskanaEngineConfiguration;
 import pro.taskana.exceptions.ClassificationNotFoundException;
 import pro.taskana.impl.configuration.TaskanaEngineConfigurationTest;
-import pro.taskana.sampledata.DBCleaner;
 import pro.taskana.sampledata.SampleDataGenerator;
 
 /**
@@ -44,17 +43,17 @@ public abstract class AbstractAccTest {
     public static void resetDb(boolean dropTables) throws SQLException, IOException {
         DataSource dataSource = TaskanaEngineConfigurationTest.getDataSource();
         String schemaName = TaskanaEngineConfigurationTest.getSchemaName();
-        DBCleaner dbCleaner = new DBCleaner();
+        SampleDataGenerator sampleDataGenerator = new SampleDataGenerator(dataSource, schemaName);
         if (dropTables) {
-            dbCleaner.dropDb(dataSource, schemaName);
+            sampleDataGenerator.dropDb();
         }
         dataSource = TaskanaEngineConfigurationTest.getDataSource();
         taskanaEngineConfiguration = new TaskanaEngineConfiguration(dataSource, false,
             schemaName);
         taskanaEngine = taskanaEngineConfiguration.buildTaskanaEngine();
         taskanaEngine.setConnectionManagementMode(ConnectionManagementMode.AUTOCOMMIT);
-        dbCleaner.clearDb(dataSource, schemaName);
+        sampleDataGenerator.clearDb();
-        new SampleDataGenerator(dataSource, schemaName).generateTestData();
+        sampleDataGenerator.generateTestData();
     }
 
     protected ObjectReference createObjectReference(String company, String system, String systemInstance, String type,

lib/taskana-core/src/test/java/acceptance/classification/GetClassificationAccTest.java

@@ -81,6 +81,13 @@ public class GetClassificationAccTest extends AbstractAccTest {
         assertEquals("custom8", classification.getCustom8());
     }
 
+    @Test
+    void testGetClassificationWithSpecialCharacter() throws ClassificationNotFoundException {
+        Classification classification = classificationService.getClassification(
+            "CLI:100000000000000000000000000000000009");
+        assertEquals("Zustimmungserklärung", classification.getName());
+    }
+
     @Test
     public void testGetClassificationAsSummary() throws ClassificationNotFoundException {
         ClassificationSummary classification = classificationService

lib/taskana-core/src/test/java/acceptance/report/AbstractReportAccTest.java

@@ -11,7 +11,6 @@ import org.junit.jupiter.api.BeforeAll;
 import pro.taskana.TaskanaEngine;
 import pro.taskana.configuration.TaskanaEngineConfiguration;
 import pro.taskana.impl.configuration.TaskanaEngineConfigurationTest;
-import pro.taskana.sampledata.DBCleaner;
 import pro.taskana.sampledata.SampleDataGenerator;
 
 /**
@@ -35,13 +34,13 @@ public class AbstractReportAccTest {
     private static void resetDb() throws SQLException, IOException {
         DataSource dataSource = TaskanaEngineConfigurationTest.getDataSource();
         String schemaName = TaskanaEngineConfigurationTest.getSchemaName();
-        DBCleaner cleaner = new DBCleaner();
+        SampleDataGenerator sampleDataGenerator = new SampleDataGenerator(dataSource, schemaName);
         taskanaEngineConfiguration = new TaskanaEngineConfiguration(dataSource, false,
             schemaName);
         taskanaEngineConfiguration.setGermanPublicHolidaysEnabled(false);
         taskanaEngine = taskanaEngineConfiguration.buildTaskanaEngine();
         taskanaEngine.setConnectionManagementMode(TaskanaEngine.ConnectionManagementMode.AUTOCOMMIT);
-        cleaner.clearDb(dataSource, schemaName);
+        sampleDataGenerator.clearDb();
-        new SampleDataGenerator(dataSource, schemaName).generateMonitorData();
+        sampleDataGenerator.generateMonitorData();
     }
 }

lib/taskana-core/src/test/java/acceptance/task/UpdateTaskAccTest.java

@@ -120,11 +120,11 @@ public class UpdateTaskAccTest extends AbstractAccTest {
         Task task2 = taskService.getTask("TKI:000000000000000000000000000000000000");
 
         task.setCustomAttribute("1", "willi");
-        Task updatedTask = null;
+        Task updatedTask = taskService.updateTask(task);
-        updatedTask = taskService.updateTask(task);
+        taskService.getTask(updatedTask.getId());
-        updatedTask = taskService.getTask(updatedTask.getId());
 
         task2.setCustomAttribute("2", "Walter");
+        //TODO flaky test ... if speed is too high,
         Assertions.assertThrows(ConcurrencyException.class, () -> taskService.updateTask(task2),
             "The task has already been updated by another user");
 

lib/taskana-core/src/test/java/pro/taskana/impl/integration/ClassificationServiceImplIntAutoCommitTest.java

@@ -32,7 +32,7 @@ import pro.taskana.exceptions.InvalidArgumentException;
 import pro.taskana.exceptions.NotAuthorizedException;
 import pro.taskana.impl.TaskanaEngineImpl;
 import pro.taskana.impl.configuration.TaskanaEngineConfigurationTest;
-import pro.taskana.sampledata.DBCleaner;
+import pro.taskana.sampledata.SampleDataGenerator;
 
 /**
  * Integration Test for ClassificationServiceImpl with connection management mode AUTOCOMMIT.
@@ -49,11 +49,10 @@ public class ClassificationServiceImplIntAutoCommitTest {
     private TaskanaEngineImpl taskanaEngineImpl;
 
     @BeforeClass
-    public static void resetDb() throws SQLException {
+    public static void resetDb() {
         DataSource ds = TaskanaEngineConfigurationTest.getDataSource();
-        DBCleaner cleaner = new DBCleaner();
         String schemaName = TaskanaEngineConfigurationTest.getSchemaName();
-        cleaner.dropDb(ds, schemaName);
+        new SampleDataGenerator(ds, schemaName).dropDb();
     }
 
     @Before
@@ -66,8 +65,8 @@ public class ClassificationServiceImplIntAutoCommitTest {
         classificationService = taskanaEngine.getClassificationService();
         taskanaEngineImpl = (TaskanaEngineImpl) taskanaEngine;
         taskanaEngineImpl.setConnectionManagementMode(ConnectionManagementMode.AUTOCOMMIT);
-        DBCleaner cleaner = new DBCleaner();
+        SampleDataGenerator sampleDataGenerator = new SampleDataGenerator(dataSource, schemaName);
-        cleaner.clearDb(dataSource, schemaName);
+        sampleDataGenerator.clearDb();
     }
 
     @Test

lib/taskana-core/src/test/java/pro/taskana/impl/integration/ClassificationServiceImplIntExplicitTest.java

@@ -39,7 +39,7 @@ import pro.taskana.exceptions.NotAuthorizedException;
 import pro.taskana.impl.ClassificationImpl;
 import pro.taskana.impl.TaskanaEngineImpl;
 import pro.taskana.impl.configuration.TaskanaEngineConfigurationTest;
-import pro.taskana.sampledata.DBCleaner;
+import pro.taskana.sampledata.SampleDataGenerator;
 
 /**
  * Integration Test for ClassificationServiceImpl with connection management mode EXPLICIT.
@@ -60,9 +60,8 @@ public class ClassificationServiceImplIntExplicitTest {
     @BeforeClass
     public static void resetDb() throws SQLException {
         DataSource ds = TaskanaEngineConfigurationTest.getDataSource();
-        DBCleaner cleaner = new DBCleaner();
         String schemaName = TaskanaEngineConfigurationTest.getSchemaName();
-        cleaner.dropDb(ds, schemaName);
+        new SampleDataGenerator(ds, schemaName).dropDb();
     }
 
     @Before
@@ -75,8 +74,8 @@ public class ClassificationServiceImplIntExplicitTest {
         classificationService = taskanaEngine.getClassificationService();
         taskanaEngineImpl = (TaskanaEngineImpl) taskanaEngine;
         taskanaEngineImpl.setConnectionManagementMode(ConnectionManagementMode.EXPLICIT);
-        DBCleaner cleaner = new DBCleaner();
+        SampleDataGenerator sampleDataGenerator = new SampleDataGenerator(dataSource, schemaName);
-        cleaner.clearDb(dataSource, schemaName);
+        sampleDataGenerator.clearDb();
     }
 
     @Test

lib/taskana-core/src/test/java/pro/taskana/impl/integration/TaskServiceImplIntAutocommitTest.java

@@ -50,7 +50,7 @@ import pro.taskana.impl.TaskanaEngineImpl;
 import pro.taskana.impl.WorkbasketImpl;
 import pro.taskana.impl.configuration.TaskanaEngineConfigurationTest;
 import pro.taskana.impl.util.IdGenerator;
-import pro.taskana.sampledata.DBCleaner;
+import pro.taskana.sampledata.SampleDataGenerator;
 import pro.taskana.security.CurrentUserContext;
 import pro.taskana.security.JAASExtension;
 import pro.taskana.security.WithAccessId;
@@ -90,8 +90,8 @@ class TaskServiceImplIntAutocommitTest {
         taskServiceImpl = (TaskServiceImpl) taskanaEngine.getTaskService();
         classificationService = taskanaEngine.getClassificationService();
         workbasketService = taskanaEngine.getWorkbasketService();
-        DBCleaner cleaner = new DBCleaner();
+        SampleDataGenerator sampleDataGenerator = new SampleDataGenerator(dataSource, schemaName);
-        cleaner.clearDb(dataSource, schemaName);
+        sampleDataGenerator.clearDb();
     }
 
     @Test

lib/taskana-core/src/test/java/pro/taskana/impl/integration/TaskServiceImplIntExplicitTest.java

@@ -56,7 +56,7 @@ import pro.taskana.impl.WorkbasketImpl;
 import pro.taskana.impl.WorkbasketSummaryImpl;
 import pro.taskana.impl.configuration.TaskanaEngineConfigurationTest;
 import pro.taskana.impl.util.IdGenerator;
-import pro.taskana.sampledata.DBCleaner;
+import pro.taskana.sampledata.SampleDataGenerator;
 import pro.taskana.security.CurrentUserContext;
 import pro.taskana.security.JAASExtension;
 import pro.taskana.security.WithAccessId;
@@ -71,8 +71,6 @@ class TaskServiceImplIntExplicitTest {
 
     private static DataSource dataSource;
 
-    private static DBCleaner cleaner;
-
     private static TaskServiceImpl taskServiceImpl;
 
     private static TaskanaEngineConfiguration taskanaEngineConfiguration;
@@ -101,15 +99,15 @@ class TaskServiceImplIntExplicitTest {
         classificationService = taskanaEngine.getClassificationService();
         taskanaEngineImpl.setConnectionManagementMode(ConnectionManagementMode.EXPLICIT);
         workbasketService = taskanaEngine.getWorkbasketService();
-        cleaner = new DBCleaner();
         DbSchemaCreator creator = new DbSchemaCreator(dataSource, dataSource.getConnection().getSchema());
         creator.run();
     }
 
     @BeforeEach
-    void resetDb() throws SQLException {
+    void resetDb() {
         String schemaName = TaskanaEngineConfigurationTest.getSchemaName();
-        cleaner.clearDb(dataSource, schemaName);
+        SampleDataGenerator sampleDataGenerator = new SampleDataGenerator(dataSource, schemaName);
+        sampleDataGenerator.clearDb();
     }
 
     @WithAccessId(userName = "Elena", groupNames = {"businessadmin"})

lib/taskana-core/src/test/java/pro/taskana/impl/integration/WorkbasketServiceImplIntAutocommitTest.java

@@ -40,7 +40,7 @@ import pro.taskana.impl.WorkbasketImpl;
 import pro.taskana.impl.configuration.TaskanaEngineConfigurationTest;
 import pro.taskana.impl.util.IdGenerator;
 import pro.taskana.mappings.WorkbasketMapper;
-import pro.taskana.sampledata.DBCleaner;
+import pro.taskana.sampledata.SampleDataGenerator;
 import pro.taskana.security.JAASRunner;
 import pro.taskana.security.WithAccessId;
 
@@ -62,9 +62,8 @@ public class WorkbasketServiceImplIntAutocommitTest {
     @BeforeClass
     public static void resetDb() throws SQLException {
         DataSource ds = TaskanaEngineConfigurationTest.getDataSource();
-        DBCleaner cleaner = new DBCleaner();
         String schemaName = TaskanaEngineConfigurationTest.getSchemaName();
-        cleaner.dropDb(ds, schemaName);
+        new SampleDataGenerator(ds, schemaName).dropDb();
     }
 
     @Before
@@ -76,8 +75,8 @@ public class WorkbasketServiceImplIntAutocommitTest {
         taskanaEngine = taskanaEngineConfiguration.buildTaskanaEngine();
         taskanaEngine.setConnectionManagementMode(ConnectionManagementMode.AUTOCOMMIT);
         workBasketService = taskanaEngine.getWorkbasketService();
-        DBCleaner cleaner = new DBCleaner();
+        SampleDataGenerator sampleDataGenerator = new SampleDataGenerator(dataSource, schemaName);
-        cleaner.clearDb(dataSource, schemaName);
+        sampleDataGenerator.clearDb();
         now = Instant.now();
     }
 

lib/taskana-core/src/test/java/pro/taskana/impl/integration/WorkbasketServiceImplIntExplicitTest.java

@@ -33,7 +33,7 @@ import pro.taskana.impl.TaskanaEngineImpl;
 import pro.taskana.impl.WorkbasketImpl;
 import pro.taskana.impl.configuration.TaskanaEngineConfigurationTest;
 import pro.taskana.impl.util.IdGenerator;
-import pro.taskana.sampledata.DBCleaner;
+import pro.taskana.sampledata.SampleDataGenerator;
 import pro.taskana.security.JAASRunner;
 import pro.taskana.security.WithAccessId;
 
@@ -54,11 +54,10 @@ public class WorkbasketServiceImplIntExplicitTest {
     private WorkbasketService workBasketService;
 
     @BeforeClass
-    public static void resetDb() throws SQLException {
+    public static void resetDb() {
         DataSource ds = TaskanaEngineConfigurationTest.getDataSource();
-        DBCleaner cleaner = new DBCleaner();
         String schemaName = TaskanaEngineConfigurationTest.getSchemaName();
-        cleaner.dropDb(ds, schemaName);
+        new SampleDataGenerator(ds, schemaName).dropDb();
     }
 
     @Before
@@ -70,8 +69,8 @@ public class WorkbasketServiceImplIntExplicitTest {
         taskanaEngine = taskanaEngineConfiguration.buildTaskanaEngine();
         taskanaEngineImpl = (TaskanaEngineImpl) taskanaEngine;
         taskanaEngineImpl.setConnectionManagementMode(ConnectionManagementMode.EXPLICIT);
-        DBCleaner cleaner = new DBCleaner();
+        SampleDataGenerator sampleDataGenerator = new SampleDataGenerator(dataSource, schemaName);
-        cleaner.clearDb(dataSource, schemaName);
+        sampleDataGenerator.clearDb();
     }
 
     @WithAccessId(userName = "Elena", groupNames = {"businessadmin"})

lib/taskana-core/src/test/java/pro/taskana/sampledata/SampleDataGeneratorTest.java

@@ -11,13 +11,27 @@ import pro.taskana.configuration.DbSchemaCreator;
  */
 class SampleDataGeneratorTest {
 
+    private static final String JDBC_URL = "jdbc:h2:mem:taskana;IGNORECASE=TRUE;LOCK_MODE=0;INIT=CREATE SCHEMA IF NOT EXISTS TASKANA";
+
     @Test
     void getScriptsValidSql() {
         PooledDataSource pooledDataSource = new PooledDataSource("org.h2.Driver",
-            "jdbc:h2:mem:taskana;IGNORECASE=TRUE;LOCK_MODE=0;INIT=CREATE SCHEMA IF NOT EXISTS TASKANA", "sa", "sa");
+            JDBC_URL, "sa", "sa");
         Assertions.assertDoesNotThrow(() -> new DbSchemaCreator(pooledDataSource, "TASKANA").run());
         Assertions.assertDoesNotThrow(() -> new SampleDataGenerator(pooledDataSource, "TASKANA").generateSampleData());
         pooledDataSource.forceCloseAll();
     }
 
+    @Test
+    void tableExists() {
+        PooledDataSource pooledDataSource = new PooledDataSource("org.h2.Driver",
+            JDBC_URL, "sa", "sa");
+        Assertions.assertDoesNotThrow(() -> new DbSchemaCreator(pooledDataSource, "TASKANA").run());
+
+        SampleDataGenerator sampleDataGenerator = new SampleDataGenerator(pooledDataSource, "TASKANA");
+        Assertions.assertTrue(sampleDataGenerator.tableExists("TASK"));
+        Assertions.assertFalse(sampleDataGenerator.tableExists("TASKRANDOM"));
+        pooledDataSource.forceCloseAll();
+    }
+
 }

lib/taskana-data/src/main/java/pro/taskana/sampledata/DBCleaner.java

@@ -1,22 +0,0 @@
-package pro.taskana.sampledata;
-
-import java.sql.SQLException;
-
-import javax.sql.DataSource;
-
-/**
- * This class cleans the complete database.
- */
-public class DBCleaner {
-
-    public void clearDb(DataSource dataSource, String schema) throws SQLException {
-        SampleDataGenerator sampleDataGenerator = new SampleDataGenerator(dataSource, schema);
-        sampleDataGenerator.runScripts(sampleDataGenerator::clearDb);
-    }
-
-    public void dropDb(DataSource dataSource, String schema) throws SQLException {
-        SampleDataGenerator sampleDataGenerator = new SampleDataGenerator(dataSource, schema);
-        sampleDataGenerator.runScripts(sampleDataGenerator::dropDb);
-
-    }
-}

lib/taskana-data/src/main/java/pro/taskana/sampledata/SQLReplacer.java

@@ -1,8 +1,6 @@
 package pro.taskana.sampledata;
 
 import java.io.BufferedReader;
-import java.io.IOException;
-import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.nio.charset.StandardCharsets;
 import java.time.LocalDateTime;
@@ -21,51 +19,24 @@ final class SQLReplacer {
     static final Pattern RELATIVE_DATE_PATTERN = Pattern.compile(RELATIVE_DATE_REGEX);
     static final DateTimeFormatter DATE_TIME_FORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS");
 
-    static String getScriptAsSql(String dbProductName, LocalDateTime now, String scriptPath) {
-        return parseAndReplace(SQLReplacer.class.getResourceAsStream(scriptPath), now, dbProductName);
-    }
-
     private SQLReplacer() {
     }
 
-    /**
+    static String getScriptAsSql(String dbProductName, LocalDateTime now, String scriptPath) {
-     * This method resolves the custom sql function defined through this regex: {@value RELATIVE_DATE_REGEX}.
+        return parseAndReplace(getScriptBufferedStream(scriptPath), now, dbProductName);
-     * Its parameter is a digit representing the relative offset of a given starting point date.
-     * <p/>
-     * Yes, this can be done as an actual sql function, but that'd lead to a little more complexity
-     * (and thus we'd have to maintain the code for db compatibility ...)
-     * Since we're already replacing the boolean attributes of sql files this addition is not a huge computational cost.
-     *
-     * @param now anchor for relative date conversion.
-     * @param sql sql statement which may contain the above declared custom function.
-     * @return sql statement with the given function resolved, if the 'sql' parameter contained any.
-     */
-    private static String replaceRelativeTimeFunction(LocalDateTime now, String sql) {
-        Matcher m = RELATIVE_DATE_PATTERN.matcher(sql);
-        StringBuffer sb = new StringBuffer(sql.length());
-        while (m.find()) {
-            m.appendReplacement(sb,
-                "'" + now.plusDays(Long.parseLong(m.group(1))).format(DATE_TIME_FORMATTER) + "'");
-        }
-        m.appendTail(sb);
-        return sb.toString();
     }
 
     private static String replaceBooleanWithInteger(String sql) {
         return sql.replaceAll("(?i)true", "1").replaceAll("(?i)false", "0");
     }
 
-    private static String parseAndReplace(InputStream stream, LocalDateTime now, String dbProductname) {
+    private static String parseAndReplace(BufferedReader bufferedReader, LocalDateTime now, String dbProductname) {
         boolean isDb2 = isDb2(dbProductname);
-        try (BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(stream))) {
         String sql = bufferedReader.lines().collect(Collectors.joining(System.lineSeparator()));
         if (isDb2) {
             sql = replaceBooleanWithInteger(sql);
         }
-            return replaceRelativeTimeFunction(now, sql);
+        return replaceDatePlaceholder(now, sql);
-        } catch (IOException e) {
-            throw new RuntimeException("Scriptfile not found", e);
-        }
     }
 
     static boolean isPostgreSQL(String databaseProductName) {
@@ -106,18 +77,13 @@ final class SQLReplacer {
         return "'" + now.plusDays(days).format(DATE_TIME_FORMATTER) + "'";
     }
 
-    static String parseAndReplace(LocalDateTime now, String script) {
-        return replaceDatePlaceholder(now,
-            getScriptAsString(script));
-    }
-
-    private static String getScriptAsString(String script) {
-        return getScriptBufferedStream(script).lines().collect(Collectors.joining(System.lineSeparator()));
-    }
-
     static BufferedReader getScriptBufferedStream(String script) {
         return Optional.ofNullable(SampleDataGenerator.class.getResourceAsStream(script)).map(
             inputStream -> new BufferedReader(
                 new InputStreamReader(inputStream, StandardCharsets.UTF_8))).orElse(null);
     }
+
+    static String getSanitizedTableName(String table) {
+        return table.replaceAll("[^a-zA-Z0-9_]", "__");
+    }
 }

lib/taskana-data/src/main/java/pro/taskana/sampledata/SampleDataGenerator.java

@@ -17,6 +17,7 @@ import java.util.stream.Stream;
 import javax.sql.DataSource;
 
 import org.apache.ibatis.jdbc.ScriptRunner;
+import org.apache.ibatis.jdbc.SqlRunner;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -27,13 +28,12 @@ public class SampleDataGenerator {
 
     private static final Logger LOGGER = LoggerFactory.getLogger(SampleDataGenerator.class);
 
-    private static final String DB_CLEAR_TABLES_SCRIPT = "/sql/clear/clear-db.sql";
+    private static final String CACHED_TEST = "TEST";
-    private static final String DB_DROP_TABLES_SCRIPT = "/sql/clear/drop-tables.sql";
+    private static final String CACHED_SAMPLE = "SAMPLE";
-    private static final String CHECK_HISTORY_EVENT_EXIST = "/sql/sample-data/check-history-event-exist.sql";
+    private static final String CACHED_EVENTSAMPLE = "EVENTSAMPLE";
-    public static final String CACHED_TEST = "TEST";
+    private static final String CACHED_MONITOR = "MONITOR";
-    public static final String CACHED_SAMPLE = "SAMPLE";
+    private static final String CACHED_CLEARDB = "CLEARDB";
-    public static final String CACHED_EVENTSAMPLE = "EVENTSAMPLE";
+    private static final String CACHED_DROPDB = "DROPDB";
-    public static final String CACHED_MONITOR = "MONITOR";
 
     private final DataSource dataSource;
     private final LocalDateTime now;
@@ -44,7 +44,7 @@ public class SampleDataGenerator {
      */
     private final String schema;
 
-    private static HashMap<String, List<String>> cachedScripts = new HashMap<String, List<String>>();
+    private static HashMap<String, List<String>> cachedScripts = new HashMap<>();
 
     public SampleDataGenerator(DataSource dataSource, String schema) {
         this(dataSource, schema, LocalDateTime.now());
@@ -56,7 +56,67 @@ public class SampleDataGenerator {
         this.now = now;
     }
 
-    public void runScripts(Consumer<ScriptRunner> consumer) {
+    public void generateSampleData() {
+        runScripts((runner) -> {
+            clearDb();
+            Stream<String> scripts;
+            String cacheKey;
+            //dbtable constants?
+            if (tableExists("HISTORY_EVENTS")) {
+                scripts = SampleDataProvider.getDefaultScripts();
+                cacheKey = CACHED_EVENTSAMPLE;
+            } else {
+                scripts = SampleDataProvider.getScriptsWithEvents();
+                cacheKey = CACHED_SAMPLE;
+            }
+            executeAndCacheScripts(scripts, cacheKey);
+        });
+    }
+
+    public void generateTestData() {
+        Stream<String> scripts = SampleDataProvider.getTestDataScripts();
+        executeAndCacheScripts(scripts, CACHED_TEST);
+    }
+
+    public void generateMonitorData() {
+        Stream<String> scripts = SampleDataProvider.getMonitorDataScripts();
+        executeAndCacheScripts(scripts, CACHED_MONITOR);
+    }
+
+    public void clearDb() {
+        Stream<String> scripts = SampleDataProvider.getScriptsToClearDatabase();
+        executeAndCacheScripts(scripts, CACHED_CLEARDB);
+    }
+
+    public void dropDb() {
+        Stream<String> scripts = SampleDataProvider.getScriptsToDropDatabase();
+        executeAndCacheScripts(scripts, CACHED_DROPDB);
+    }
+
+    private List<String> parseScripts(Stream<String> scripts) {
+        try (Connection connection = dataSource.getConnection()) {
+            String dbProductName = connection.getMetaData().getDatabaseProductName();
+            return scripts.map(script -> SQLReplacer.getScriptAsSql(dbProductName, now, script))
+                .collect(Collectors.toList());
+        } catch (SQLException e) {
+            throw new RuntimeException("Connection to database failed.", e);
+        }
+    }
+
+    boolean tableExists(String table) {
+        try (Connection connection = dataSource.getConnection()) {
+            connection.setSchema(schema);
+            SqlRunner runner = new SqlRunner(connection);
+            String tableSafe = SQLReplacer.getSanitizedTableName(table);
+            String query = "SELECT 1 FROM " + tableSafe + " LIMIT 1;";
+            runner.run(query);
+            return true;
+        } catch (Exception e) {
+            return false;
+        }
+    }
+
+    private void runScripts(Consumer<ScriptRunner> consumer) {
         try (Connection connection = dataSource.getConnection()) {
             if (LOGGER.isTraceEnabled()) {
                 LOGGER.trace(connection.getMetaData().toString());
@@ -81,68 +141,15 @@ public class SampleDataGenerator {
         }
     }
 
-    public void generateSampleData() throws SQLException {
+    private void executeAndCacheScripts(Stream<String> scripts, String cacheKey) {
-        runScripts((runner) -> {
+        runScripts(runner -> cachedScripts.computeIfAbsent(cacheKey, key -> parseScripts(scripts)).stream()
-            clearDb(runner);
-            Stream<String> scripts;
-            String cacheKey;
-            try {
-                //TODO find a better method of testing if a table exists
-                runner.runScript(SQLReplacer.getScriptBufferedStream(CHECK_HISTORY_EVENT_EXIST));
-                scripts = SampleDataProvider.getScriptsWithEvents();
-                cacheKey = CACHED_SAMPLE;
-            } catch (Exception e) {
-                scripts = SampleDataProvider.getDefaultScripts();
-                cacheKey = CACHED_EVENTSAMPLE;
-            }
-            cacheAndExecute(scripts, cacheKey);
-        });
-    }
-
-    public List<String> parseScripts(Stream<String> scripts) {
-        try (Connection connection = dataSource.getConnection()) {
-            String dbProductName = connection.getMetaData().getDatabaseProductName();
-            return scripts.map(script -> SQLReplacer.getScriptAsSql(dbProductName, now, script))
-                .collect(Collectors.toList());
-        } catch (SQLException e) {
-            throw new RuntimeException("Connection to database failed.", e);
-        }
-    }
-
-    public void generateTestData() {
-        Stream<String> scripts = SampleDataProvider.getTestDataScripts();
-        cacheAndExecute(scripts, CACHED_TEST);
-    }
-
-    public void generateMonitorData() {
-        Stream<String> scripts = SampleDataProvider.getMonitorDataScripts();
-        cacheAndExecute(scripts, CACHED_MONITOR);
-    }
-
-    public void clearDb(ScriptRunner runner) {
-        runner.setStopOnError(false);
-        runner.runScript(SQLReplacer.getScriptBufferedStream(DB_CLEAR_TABLES_SCRIPT));
-        runner.setStopOnError(true);
-    }
-
-    private void cacheAndExecute(Stream<String> scripts, String cacheKey) {
-        if (!cachedScripts.containsKey(cacheKey)) {
-            cachedScripts.put(cacheKey, parseScripts(scripts));
-        }
-        runScripts(runner -> cachedScripts.get(cacheKey).stream()
             .map(s -> s.getBytes(StandardCharsets.UTF_8))
             .map(ByteArrayInputStream::new)
-            .map(InputStreamReader::new)
+            .map(s -> new InputStreamReader(s, StandardCharsets.UTF_8))
             .forEach(runner::runScript));
     }
 
-    public void dropDb(ScriptRunner runner) {
+    private ScriptRunner getScriptRunner(Connection connection, StringWriter outWriter,
-        runner.setStopOnError(false);
-        runner.runScript(SQLReplacer.getScriptBufferedStream(DB_DROP_TABLES_SCRIPT));
-        runner.setStopOnError(true);
-    }
-
-    ScriptRunner getScriptRunner(Connection connection, StringWriter outWriter,
         StringWriter errorWriter) throws SQLException {
 
         PrintWriter logWriter = new PrintWriter(outWriter);

lib/taskana-data/src/main/java/pro/taskana/sampledata/SampleDataProvider.java

@@ -7,6 +7,9 @@ import java.util.stream.Stream;
  */
 public final class SampleDataProvider {
 
+    private static final String DB_CLEAR_TABLES_SCRIPT = "/sql/clear/clear-db.sql";
+    private static final String DB_DROP_TABLES_SCRIPT = "/sql/clear/drop-tables.sql";
+
     private static final String CLEAR_HISTORY_EVENTS = "/sql/clear/clear-history-events.sql";
     private static final String HISTORY_EVENT = "/sql/sample-data/history-event.sql";
 
@@ -18,13 +21,13 @@ public final class SampleDataProvider {
     private static final String SAMPLE_OBJECT_REFERENCE = "/sql/sample-data/object-reference.sql";
     private static final String SAMPLE_ATTACHMENT = "/sql/sample-data/attachment.sql";
 
-    static final String TASK = "/sql/test-data/task.sql";
+    static final String TEST_TASK = "/sql/test-data/task.sql";
-    static final String WORKBASKET = "/sql/test-data/workbasket.sql";
+    static final String TEST_WORKBASKET = "/sql/test-data/workbasket.sql";
-    static final String DISTRIBUTION_TARGETS = "/sql/test-data/distribution-targets.sql";
+    static final String TEST_DISTRIBUTION_TARGETS = "/sql/test-data/distribution-targets.sql";
-    static final String WORKBASKET_ACCESS_LIST = "/sql/test-data/workbasket-access-list.sql";
+    static final String TEST_WORKBASKET_ACCESS_LIST = "/sql/test-data/workbasket-access-list.sql";
-    static final String CLASSIFICATION = "/sql/test-data/classification.sql";
+    static final String TEST_CLASSIFICATION = "/sql/test-data/classification.sql";
-    static final String OBJECT_REFERENCE = "/sql/test-data/object-reference.sql";
+    static final String TEST_OBJECT_REFERENCE = "/sql/test-data/object-reference.sql";
-    static final String ATTACHMENT = "/sql/test-data/attachment.sql";
+    static final String TEST_ATTACHMENT = "/sql/test-data/attachment.sql";
 
     static final String MONITOR_SAMPLE_DATA = "/sql/monitor-data/monitor-sample-data.sql";
 
@@ -42,15 +45,23 @@ public final class SampleDataProvider {
         return Stream.concat(getDefaultScripts(), Stream.of(CLEAR_HISTORY_EVENTS, HISTORY_EVENT));
     }
 
+    static Stream<String> getScriptsToClearDatabase() {
+        return Stream.concat(getDefaultScripts(), Stream.of(DB_CLEAR_TABLES_SCRIPT));
+    }
+
+    static Stream<String> getScriptsToDropDatabase() {
+        return Stream.concat(getDefaultScripts(), Stream.of(DB_DROP_TABLES_SCRIPT));
+    }
+
     static Stream<String> getTestDataScripts() {
         return Stream.of(
-            CLASSIFICATION,
+            TEST_CLASSIFICATION,
-            WORKBASKET,
+            TEST_WORKBASKET,
-            TASK,
+            TEST_TASK,
-            WORKBASKET_ACCESS_LIST,
+            TEST_WORKBASKET_ACCESS_LIST,
-            DISTRIBUTION_TARGETS,
+            TEST_DISTRIBUTION_TARGETS,
-            OBJECT_REFERENCE,
+            TEST_OBJECT_REFERENCE,
-            ATTACHMENT);
+            TEST_ATTACHMENT);
     }
 
     static Stream<String> getMonitorDataScripts() {

lib/taskana-data/src/main/resources/sql/sample-data/check-history-event-exist.sql

@@ -1 +0,0 @@
-SELECT 1 FROM HISTORY_EVENTS LIMIT 1;

lib/taskana-data/src/test/java/pro/taskana/sampledata/SQLReplacerTest.java

@@ -14,26 +14,7 @@ import org.junit.jupiter.api.Test;
 /**
  * Test SampleDataGenerator.
  */
-class SampleDataGeneratorTest {
+class SQLReplacerTest {
-
-    @Test
-    void getScriptsNotNull() {
-        Assertions.assertNotNull(SampleDataProvider.getDefaultScripts());
-        Assertions.assertNotNull(SampleDataProvider.getScriptsWithEvents());
-    }
-
-    @Test
-    void getScriptsNotEmpty() {
-        Assertions.assertTrue(SampleDataProvider.getDefaultScripts().count() > 0);
-        Assertions.assertTrue(SampleDataProvider.getScriptsWithEvents().count() > 0);
-    }
-
-    @Test
-    void getScriptsFileExists() {
-        SampleDataProvider.getDefaultScripts()
-            .map(SQLReplacer::getScriptBufferedStream)
-            .forEach(Assertions::assertNotNull);
-    }
 
     @Test
     void replaceRelativeTimeFunctionSameDate() {

lib/taskana-data/src/test/java/pro/taskana/sampledata/SampleDataProviderTest.java

@@ -0,0 +1,30 @@
+package pro.taskana.sampledata;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Test SampleDataGenerator.
+ */
+class SampleDataProviderTest {
+
+    @Test
+    void getScriptsNotNull() {
+        Assertions.assertNotNull(SampleDataProvider.getDefaultScripts());
+        Assertions.assertNotNull(SampleDataProvider.getScriptsWithEvents());
+    }
+
+    @Test
+    void getScriptsNotEmpty() {
+        Assertions.assertTrue(SampleDataProvider.getDefaultScripts().count() > 0);
+        Assertions.assertTrue(SampleDataProvider.getScriptsWithEvents().count() > 0);
+    }
+
+    @Test
+    void getScriptsFileExists() {
+        SampleDataProvider.getDefaultScripts()
+            .map(SQLReplacer::getScriptBufferedStream)
+            .forEach(Assertions::assertNotNull);
+    }
+
+}

rest/taskana-rest-spring/src/test/java/pro/taskana/rest/ClassificationControllerIntTest.java

@@ -8,7 +8,6 @@ import static org.junit.jupiter.api.Assertions.assertThrows;
 import java.io.IOException;
 
 import org.junit.jupiter.api.Assertions;
-import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.core.ParameterizedTypeReference;
@@ -37,12 +36,7 @@ class ClassificationControllerIntTest {
 
     @Autowired RestHelper restHelper;
 
-    static RestTemplate template;
+    static RestTemplate template = RestHelper.getRestTemplate();
-
-    @BeforeAll
-    static void init() {
-        template = RestHelper.getRestTemplate();
-    }
 
     @Test
     void testGetAllClassifications() {

rest/taskana-rest-spring/src/test/java/pro/taskana/rest/TaskControllerIntTest.java

@@ -14,7 +14,6 @@ import java.io.InputStreamReader;
 import java.io.OutputStreamWriter;
 import java.net.HttpURLConnection;
 import java.net.URL;
-import java.sql.SQLException;
 import java.time.Instant;
 
 import javax.sql.DataSource;
@@ -41,7 +40,6 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 import pro.taskana.ObjectReference;
 import pro.taskana.RestHelper;
 import pro.taskana.TaskanaSpringBootTest;
-import pro.taskana.exceptions.SystemException;
 import pro.taskana.rest.resource.ClassificationSummaryResource;
 import pro.taskana.rest.resource.TaskResource;
 import pro.taskana.rest.resource.TaskSummaryListResource;
@@ -71,13 +69,8 @@ class TaskControllerIntTest {
     private DataSource dataSource;
 
     void resetDb() {
-        SampleDataGenerator sampleDataGenerator;
+        SampleDataGenerator sampleDataGenerator = new SampleDataGenerator(dataSource, schemaName);
-        try {
-            sampleDataGenerator = new SampleDataGenerator(dataSource, schemaName);
         sampleDataGenerator.generateSampleData();
-        } catch (SQLException e) {
-            throw new SystemException("tried to reset DB and caught Exception " + e, e);
-        }
     }
 
     @Test