TSK-315 Store custom properties as JSON Map in DB

lib/taskana-core/pom.xml

@@ -128,7 +128,11 @@
 			<artifactId>slf4j-api</artifactId>
 			<version>1.7.25</version>
 		</dependency>
-
+        <dependency> 
+            <groupId>org.json</groupId> 
+            <artifactId>json</artifactId> 
+            <version>20180130</version>
+        </dependency>
 		<!-- test dependencies -->
 		<dependency>
 			<groupId>junit</groupId>

lib/taskana-core/src/main/java/pro/taskana/Attachment.java

@@ -103,7 +103,7 @@ public interface Attachment {
      *
      * @return customAttributes as {@link Map}
      */
-    Map<String, Object> getCustomAttributes();
+    Map<String, String> getCustomAttributes();
 
     /**
      * Sets the custom attribute Map of the attachment.
@@ -111,7 +111,8 @@ public interface Attachment {
      * @param customAttributes
      *            a {@link Map} that contains the custom attributes of the attachment as key, value pairs
      */
-    void setCustomAttributes(Map<String, Object> customAttributes);
+    void setCustomAttributes(Map<String, String> customAttributes);
+
     /**
      * Return a summary of the current Attachment.
      *

lib/taskana-core/src/main/java/pro/taskana/Task.java

@@ -220,7 +220,15 @@ public interface Task {
      *
      * @return customAttributes as {@link Map}
      */
-    Map<String, Object> getCustomAttributes();
+    Map<String, String> getCustomAttributes();
+
+    /**
+     * Sets a collection of customAttributes.
+     *
+     * @param customAttributes
+     *            a {@link Map} that contains the custom attributes
+     */
+    void setCustomAttributes(Map<String, String> customAttributes);
 
     /**
      * Return the value for the 1. customAttribute.

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

@@ -24,7 +24,7 @@ public class AttachmentImpl implements Attachment {
     private ObjectReference objectReference;
     private String channel;
     private Instant received;
-    private Map<String, Object> customAttributes = Collections.emptyMap();
+    private Map<String, String> customAttributes = Collections.emptyMap();
 
     AttachmentImpl() {
     }
@@ -116,12 +116,12 @@ public class AttachmentImpl implements Attachment {
     }
 
     @Override
-    public Map<String, Object> getCustomAttributes() {
+    public Map<String, String> getCustomAttributes() {
         return customAttributes;
     }
 
     @Override
-    public void setCustomAttributes(Map<String, Object> customAttributes) {
+    public void setCustomAttributes(Map<String, String> customAttributes) {
         this.customAttributes = customAttributes;
     }
 

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

@@ -41,7 +41,7 @@ public class TaskImpl implements Task {
     private boolean isRead;
     private boolean isTransferred;
     // All objects have to be serializable
-    private Map<String, Object> customAttributes = Collections.emptyMap();
+    private Map<String, String> customAttributes = Collections.emptyMap();
     private List<Attachment> attachments = new ArrayList<>();
     private String custom1;
     private String custom2;
@@ -294,11 +294,12 @@ public class TaskImpl implements Task {
     }
 
     @Override
-    public Map<String, Object> getCustomAttributes() {
+    public Map<String, String> getCustomAttributes() {
         return customAttributes;
     }
 
-    public void setCustomAttributes(Map<String, Object> customAttributes) {
+    @Override
+    public void setCustomAttributes(Map<String, String> customAttributes) {
         this.customAttributes = customAttributes;
     }
 

lib/taskana-core/src/main/java/pro/taskana/impl/persistence/MapTypeHandler.java

@@ -1,12 +1,7 @@
 package pro.taskana.impl.persistence;
 
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.io.ObjectInputStream;
-import java.io.ObjectOutputStream;
-import java.sql.Blob;
 import java.sql.CallableStatement;
+import java.sql.Clob;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
@@ -15,6 +10,7 @@ import java.util.Map;
 
 import org.apache.ibatis.type.BaseTypeHandler;
 import org.apache.ibatis.type.JdbcType;
+import org.json.JSONObject;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -32,15 +28,11 @@ public class MapTypeHandler extends BaseTypeHandler<Map> {
     public void setNonNullParameter(PreparedStatement ps, int i, Map parameter, JdbcType jdbcType) throws SQLException {
         if (parameter != null && parameter.size() > 0) {
             LOGGER.debug("Input-Map before serializing: ", parameter);
-            // Convert Map to byte array
+            // Convert Map to JSON string
-            try (ByteArrayOutputStream byteOut = new ByteArrayOutputStream()) {
+            JSONObject jsonObj = new JSONObject(parameter);
-                ObjectOutputStream out = new ObjectOutputStream(byteOut);
+            Clob content = ps.getConnection().createClob();
-                out.writeObject(parameter);
+            content.setString(1, jsonObj.toString());
-                ps.setBlob(i, new ByteArrayInputStream(byteOut.toByteArray()));
+            ps.setClob(i, content);
-                out.close();
-            } catch (IOException e) {
-                LOGGER.error("During serialization of 'customAttributes' an error occured: ", e);
-            }
         } else {
             ps.setNull(i, Types.BLOB);
         }
@@ -48,49 +40,36 @@ public class MapTypeHandler extends BaseTypeHandler<Map> {
 
     @Override
     public Map getNullableResult(ResultSet rs, String columnName) throws SQLException {
-        Blob fieldValue = rs.getBlob(columnName);
+        Clob fieldValue = rs.getClob(columnName);
         if (fieldValue != null) {
-            // Parse byte array to Map
+            return convertClobToMap(fieldValue);
-            Map result = null;
-            try (ObjectInputStream in = new ObjectInputStream(fieldValue.getBinaryStream())) {
-                result = (Map) in.readObject();
-            } catch (ClassNotFoundException | IOException e) {
-                LOGGER.error("During deserialization of 'customAttributes' an error occured: ", e);
-            }
-            return result;
         }
         return null;
     }
 
     @Override
     public Map getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
-        Blob fieldValue = rs.getBlob(columnIndex);
+        Clob fieldValue = rs.getClob(columnIndex);
         if (fieldValue != null) {
-            // Parse byte array to Map
+            return convertClobToMap(fieldValue);
-            Map result = null;
-            try (ObjectInputStream in = new ObjectInputStream(fieldValue.getBinaryStream())) {
-                result = (Map) in.readObject();
-            } catch (ClassNotFoundException | IOException e) {
-                LOGGER.error("During deserialization of 'customAttributes' an error occured: ", e);
-            }
-            return result;
         }
         return null;
     }
 
     @Override
     public Map getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
-        Blob fieldValue = cs.getBlob(columnIndex);
+        Clob fieldValue = cs.getClob(columnIndex);
         if (fieldValue != null) {
-            // Parse byte array to Map
+            return convertClobToMap(fieldValue);
-            Map result = null;
-            try (ObjectInputStream in = new ObjectInputStream(fieldValue.getBinaryStream())) {
-                result = (Map) in.readObject();
-            } catch (ClassNotFoundException | IOException e) {
-                LOGGER.error("During deserialization of 'customAttributes' an error occured: ", e);
-            }
-            return result;
         }
         return null;
     }
+
+    private Map convertClobToMap(Clob fieldValue) throws SQLException {
+        String content = fieldValue.getSubString(1L, (int) fieldValue.length());
+        JSONObject jsonObj = new JSONObject(content);
+        Map result = jsonObj.toMap();
+        return result;
+    }
+
 }

lib/taskana-core/src/main/java/pro/taskana/mappings/AttachmentMapper.java

@@ -10,6 +10,7 @@ import org.apache.ibatis.annotations.Result;
 import org.apache.ibatis.annotations.Results;
 import org.apache.ibatis.annotations.Select;
 import org.apache.ibatis.annotations.Update;
+import org.apache.ibatis.type.ClobTypeHandler;
 import org.apache.ibatis.type.JdbcType;
 
 import pro.taskana.impl.AttachmentImpl;
@@ -23,7 +24,7 @@ public interface AttachmentMapper {
 
     @Insert("INSERT INTO ATTACHMENT (ID, TASK_ID, CREATED, MODIFIED, CLASSIFICATION_KEY, CLASSIFICATION_ID, REF_COMPANY, REF_SYSTEM, REF_INSTANCE, REF_TYPE, REF_VALUE, CHANNEL, RECEIVED, CUSTOM_ATTRIBUTES) "
         + "VALUES (#{att.id}, #{att.taskId}, #{att.created}, #{att.modified}, #{att.classificationSummary.key}, #{att.classificationSummary.id}, #{att.objectReference.company}, #{att.objectReference.system}, #{att.objectReference.systemInstance}, "
-        + " #{att.objectReference.type}, #{att.objectReference.value}, #{att.channel}, #{att.received}, #{att.customAttributes,jdbcType=BLOB,javaType=java.util.Map,typeHandler=pro.taskana.impl.persistence.MapTypeHandler} )")
+        + " #{att.objectReference.type}, #{att.objectReference.value}, #{att.channel}, #{att.received}, #{att.customAttributes,jdbcType=CLOB,javaType=java.util.Map,typeHandler=pro.taskana.impl.persistence.MapTypeHandler} )")
     void insert(@Param("att") AttachmentImpl att);
 
     @Select("SELECT ID, TASK_ID, CREATED, MODIFIED, CLASSIFICATION_KEY, CLASSIFICATION_ID, REF_COMPANY, REF_SYSTEM, REF_INSTANCE, REF_TYPE, REF_VALUE, CHANNEL, RECEIVED, CUSTOM_ATTRIBUTES "
@@ -43,7 +44,7 @@ public interface AttachmentMapper {
         @Result(property = "objectReference.value", column = "REF_VALUE"),
         @Result(property = "channel", column = "CHANNEL"),
         @Result(property = "received", column = "RECEIVED"),
-        @Result(property = "customAttributes", column = "CUSTOM_ATTRIBUTES", jdbcType = JdbcType.BLOB,
+        @Result(property = "customAttributes", column = "CUSTOM_ATTRIBUTES", jdbcType = JdbcType.CLOB,
             javaType = Map.class, typeHandler = MapTypeHandler.class)
     })
     List<AttachmentImpl> findAttachmentsByTaskId(@Param("taskId") String taskId);
@@ -65,7 +66,7 @@ public interface AttachmentMapper {
         @Result(property = "objectReference.value", column = "REF_VALUE"),
         @Result(property = "channel", column = "CHANNEL"),
         @Result(property = "received", column = "RECEIVED"),
-        @Result(property = "customAttributes", column = "CUSTOM_ATTRIBUTES", jdbcType = JdbcType.BLOB,
+        @Result(property = "customAttributes", column = "CUSTOM_ATTRIBUTES", jdbcType = JdbcType.CLOB,
             javaType = Map.class, typeHandler = MapTypeHandler.class)
     })
     AttachmentImpl getAttachment(@Param("attachmentId") String attachmentId);
@@ -93,7 +94,14 @@ public interface AttachmentMapper {
     @Update("UPDATE ATTACHMENT SET TASK_ID = #{taskId}, CREATED = #{created}, MODIFIED = #{modified},"
         + " CLASSIFICATION_KEY = #{classificationSummary.key}, CLASSIFICATION_ID = #{classificationSummary.id}, REF_COMPANY = #{objectReference.company}, REF_SYSTEM = #{objectReference.system},"
         + " REF_INSTANCE = #{objectReference.systemInstance}, REF_TYPE = #{objectReference.type}, REF_VALUE = #{objectReference.value},"
-        + " CHANNEL = #{channel}, RECEIVED = #{received}, CUSTOM_ATTRIBUTES = #{customAttributes,jdbcType=BLOB,javaType=java.util.Map,typeHandler=pro.taskana.impl.persistence.MapTypeHandler}"
+        + " CHANNEL = #{channel}, RECEIVED = #{received}, CUSTOM_ATTRIBUTES = #{customAttributes,jdbcType=CLOB,javaType=java.util.Map,typeHandler=pro.taskana.impl.persistence.MapTypeHandler}"
         + " WHERE ID = #{id}")
     void update(AttachmentImpl attachment);
+
+    @Select("select CUSTOM_ATTRIBUTES from attachment where id = #{attachmentId}")
+    @Results(value = {
+        @Result(property = "customAttributes", column = "CUSTOM_ATTRIBUTES", jdbcType = JdbcType.CLOB,
+            javaType = String.class, typeHandler = ClobTypeHandler.class)
+    })
+    String getCustomAttributesAsString(@Param("attachmentId") String attachmentId);
 }

lib/taskana-core/src/main/java/pro/taskana/mappings/TaskMapper.java

@@ -12,6 +12,7 @@ import org.apache.ibatis.annotations.Result;
 import org.apache.ibatis.annotations.Results;
 import org.apache.ibatis.annotations.Select;
 import org.apache.ibatis.annotations.Update;
+import org.apache.ibatis.type.ClobTypeHandler;
 import org.apache.ibatis.type.JdbcType;
 
 import pro.taskana.impl.MinimalTaskSummary;
@@ -63,7 +64,7 @@ public interface TaskMapper {
         @Result(property = "primaryObjRef.value", column = "POR_VALUE"),
         @Result(property = "isRead", column = "IS_READ"),
         @Result(property = "isTransferred", column = "IS_TRANSFERRED"),
-        @Result(property = "customAttributes", column = "CUSTOM_ATTRIBUTES", jdbcType = JdbcType.BLOB,
+        @Result(property = "customAttributes", column = "CUSTOM_ATTRIBUTES", jdbcType = JdbcType.CLOB,
             javaType = Map.class, typeHandler = MapTypeHandler.class),
         @Result(property = "custom1", column = "CUSTOM_1"),
         @Result(property = "custom2", column = "CUSTOM_2"),
@@ -83,7 +84,7 @@ public interface TaskMapper {
         + "VALUES(#{id}, #{created}, #{claimed}, #{completed}, #{modified}, #{planned}, #{due}, #{name}, #{creator}, #{description}, #{note}, #{priority}, #{state}, #{classificationSummary.category}, "
         + "#{classificationSummary.key}, #{classificationSummary.id}, #{workbasketSummary.id}, #{workbasketSummary.key}, #{workbasketSummary.domain}, #{businessProcessId}, "
         + "#{parentBusinessProcessId}, #{owner}, #{primaryObjRef.company}, #{primaryObjRef.system}, #{primaryObjRef.systemInstance}, #{primaryObjRef.type}, #{primaryObjRef.value}, "
-        + "#{isRead}, #{isTransferred}, #{customAttributes,jdbcType=BLOB,javaType=java.util.Map,typeHandler=pro.taskana.impl.persistence.MapTypeHandler}, "
+        + "#{isRead}, #{isTransferred}, #{customAttributes,jdbcType=CLOB,javaType=java.util.Map,typeHandler=pro.taskana.impl.persistence.MapTypeHandler}, "
         + "#{custom1}, #{custom2}, #{custom3}, #{custom4}, #{custom5}, #{custom6}, #{custom7}, #{custom8}, #{custom9}, #{custom10})")
     @Options(keyProperty = "id", keyColumn = "ID")
     void insert(TaskImpl task);
@@ -93,7 +94,7 @@ public interface TaskMapper {
         + "WORKBASKET_ID = #{workbasketSummary.id}, WORKBASKET_KEY = #{workbasketSummary.key}, DOMAIN = #{workbasketSummary.domain}, "
         + "BUSINESS_PROCESS_ID = #{businessProcessId}, PARENT_BUSINESS_PROCESS_ID = #{parentBusinessProcessId}, OWNER = #{owner}, POR_COMPANY = #{primaryObjRef.company}, POR_SYSTEM = #{primaryObjRef.system}, "
         + "POR_INSTANCE = #{primaryObjRef.systemInstance}, POR_TYPE = #{primaryObjRef.type}, POR_VALUE = #{primaryObjRef.value}, IS_READ = #{isRead}, IS_TRANSFERRED = #{isTransferred}, "
-        + "CUSTOM_ATTRIBUTES = #{customAttributes,jdbcType=BLOB,javaType=java.util.Map,typeHandler=pro.taskana.impl.persistence.MapTypeHandler}, CUSTOM_1 = #{custom1}, CUSTOM_2 = #{custom2}, "
+        + "CUSTOM_ATTRIBUTES = #{customAttributes,jdbcType=CLOB,javaType=java.util.Map,typeHandler=pro.taskana.impl.persistence.MapTypeHandler}, CUSTOM_1 = #{custom1}, CUSTOM_2 = #{custom2}, "
         + "CUSTOM_3 = #{custom3}, CUSTOM_4 = #{custom4}, CUSTOM_5 = #{custom5}, CUSTOM_6 = #{custom6}, CUSTOM_7 = #{custom7}, CUSTOM_8 = #{custom8}, CUSTOM_9 = #{custom9}, CUSTOM_10 = #{custom10} "
         + "WHERE ID = #{id}")
     void update(TaskImpl task);
@@ -223,4 +224,12 @@ public interface TaskMapper {
         + "</script>")
     void updateClassificationCategoryOnChange(@Param("taskIds") List<String> taskIds,
         @Param("newCategory") String newCategory);
+
+    @Select("select CUSTOM_ATTRIBUTES from task where id = #{taskId}")
+    @Results(value = {
+        @Result(property = "customAttributes", column = "CUSTOM_ATTRIBUTES", jdbcType = JdbcType.CLOB,
+            javaType = String.class, typeHandler = ClobTypeHandler.class)
+    })
+    String getCustomAttributesAsString(@Param("taskId") String taskId);
+
 }

lib/taskana-core/src/main/resources/sql/taskana-schema.sql

@@ -83,7 +83,7 @@ CREATE TABLE TASK (
         POR_VALUE VARCHAR(128) NOT NULL,
         IS_READ BOOLEAN NOT NULL,
         IS_TRANSFERRED BOOLEAN NOT NULL,
-        CUSTOM_ATTRIBUTES BLOB NULL,
+        CUSTOM_ATTRIBUTES CLOB NULL,
         CUSTOM_1 VARCHAR(255) NULL,
         CUSTOM_2 VARCHAR(255) NULL,
         CUSTOM_3 VARCHAR(255) NULL,
@@ -152,7 +152,7 @@ CREATE TABLE ATTACHMENT(
     REF_VALUE VARCHAR(128) NOT NULL,
     CHANNEL VARCHAR(64) NULL,
     RECEIVED TIMESTAMP NULL,
-    CUSTOM_ATTRIBUTES BLOB NULL,
+    CUSTOM_ATTRIBUTES CLOB NULL,
     PRIMARY KEY (ID),
     CONSTRAINT ATT_CLASS FOREIGN KEY (CLASSIFICATION_ID) REFERENCES CLASSIFICATION ON DELETE NO ACTION
 );

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

@@ -68,8 +68,8 @@ public abstract class AbstractAccTest {
         return objectReference;
     }
 
-    protected Map<String, Object> createSimpleCustomProperties(int propertiesCount) {
+    protected Map<String, String> createSimpleCustomProperties(int propertiesCount) {
-        HashMap<String, Object> properties = new HashMap<>();
+        HashMap<String, String> properties = new HashMap<>();
         for (int i = 1; i <= propertiesCount; i++) {
             properties.put("Property_" + i, "Property Value of Property_" + i);
         }
@@ -77,7 +77,7 @@ public abstract class AbstractAccTest {
     }
 
     protected Attachment createAttachment(String classificationKey, ObjectReference objRef,
-        String channel, String receivedDate, Map<String, Object> customAttributes)
+        String channel, String receivedDate, Map<String, String> customAttributes)
         throws ClassificationNotFoundException, NotAuthorizedException {
         Attachment attachment = taskanaEngine.getTaskService().newAttachment();
 

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

@@ -4,10 +4,13 @@ import static org.hamcrest.CoreMatchers.equalTo;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 import java.sql.SQLException;
+import java.util.Map;
 
+import org.apache.ibatis.session.SqlSession;
 import org.h2.store.fs.FileUtils;
 import org.junit.AfterClass;
 import org.junit.Test;
@@ -28,6 +31,10 @@ import pro.taskana.exceptions.TaskNotFoundException;
 import pro.taskana.exceptions.WorkbasketNotFoundException;
 import pro.taskana.impl.TaskState;
 import pro.taskana.security.CurrentUserContext;
+import pro.taskana.impl.TaskanaEngineImpl;
+import pro.taskana.impl.TaskanaEngineProxyForTest;
+import pro.taskana.mappings.AttachmentMapper;
+import pro.taskana.mappings.TaskMapper;
 import pro.taskana.security.JAASRunner;
 import pro.taskana.security.WithAccessId;
 
@@ -73,6 +80,68 @@ public class CreateTaskAccTest extends AbstractAccTest {
         assertEquals(false, createdTask.isTransferred());
     }
 
+    @WithAccessId(
+        userName = "user_1_1",
+        groupNames = {"group_1"})
+    @Test
+    public void testCreateSimpleTaskWithCustomAttributes()
+        throws SQLException, NotAuthorizedException, InvalidArgumentException, ClassificationNotFoundException,
+        WorkbasketNotFoundException, TaskAlreadyExistException, InvalidWorkbasketException, TaskNotFoundException {
+
+        TaskService taskService = taskanaEngine.getTaskService();
+        Task newTask = taskService.newTask("USER_1_1", "DOMAIN_A");
+        newTask.setClassificationKey("T2100");
+        newTask.setPrimaryObjRef(createObjectReference("COMPANY_A", "SYSTEM_A", "INSTANCE_A", "VNR", "1234567"));
+        Map<String, String> customAttributesForCreate = createSimpleCustomProperties(13);
+        newTask.setCustomAttributes(customAttributesForCreate);
+        Task createdTask = taskService.createTask(newTask);
+
+        assertNotNull(createdTask);
+        assertEquals("T-Vertragstermin VERA", createdTask.getName());
+        assertEquals("1234567", createdTask.getPrimaryObjRef().getValue());
+        assertNotNull(createdTask.getCreated());
+        assertNotNull(createdTask.getModified());
+        assertNotNull(createdTask.getBusinessProcessId());
+        assertEquals(null, createdTask.getClaimed());
+        assertEquals(null, createdTask.getCompleted());
+        assertEquals(createdTask.getCreated(), createdTask.getModified());
+        assertEquals(createdTask.getCreated(), createdTask.getPlanned());
+        assertEquals(TaskState.READY, createdTask.getState());
+        assertEquals(null, createdTask.getParentBusinessProcessId());
+        assertEquals(2, createdTask.getPriority());
+        assertEquals(false, createdTask.isRead());
+        assertEquals(false, createdTask.isTransferred());
+        // verify that the database content is as expected
+        TaskanaEngineProxyForTest engineProxy = new TaskanaEngineProxyForTest((TaskanaEngineImpl) taskanaEngine);
+        try {
+            SqlSession session = engineProxy.getSqlSession();
+            TaskMapper mapper = session.getMapper(TaskMapper.class);
+            engineProxy.openConnection();
+            String customProperties = mapper.getCustomAttributesAsString(createdTask.getId());
+            assertTrue(customProperties.contains("\"Property_13\":\"Property Value of Property_13\""));
+            assertTrue(customProperties.contains("\"Property_12\":\"Property Value of Property_12\""));
+            assertTrue(customProperties.contains("\"Property_11\":\"Property Value of Property_11\""));
+            assertTrue(customProperties.contains("\"Property_10\":\"Property Value of Property_10\""));
+            assertTrue(customProperties.contains("\"Property_9\":\"Property Value of Property_9\""));
+            assertTrue(customProperties.contains("\"Property_8\":\"Property Value of Property_8\""));
+            assertTrue(customProperties.contains("\"Property_7\":\"Property Value of Property_7\""));
+            assertTrue(customProperties.contains("\"Property_6\":\"Property Value of Property_6\""));
+            assertTrue(customProperties.contains("\"Property_5\":\"Property Value of Property_5\""));
+            assertTrue(customProperties.contains("\"Property_4\":\"Property Value of Property_4\""));
+            assertTrue(customProperties.contains("\"Property_3\":\"Property Value of Property_3\""));
+            assertTrue(customProperties.contains("\"Property_2\":\"Property Value of Property_2\""));
+            assertTrue(customProperties.contains("\"Property_1\":\"Property Value of Property_1\""));
+        } finally {
+            engineProxy.returnConnection();
+        }
+        // verify that the map is correctly retrieved from the database
+        Task retrievedTask = taskService.getTask(createdTask.getId());
+        Map<String, String> customAttributesFromDb = retrievedTask.getCustomAttributes();
+        assertNotNull(customAttributesFromDb);
+        assertTrue(customAttributesFromDb.equals(customAttributesForCreate));
+
+    }
+
     @WithAccessId(
         userName = "user_1_1",
         groupNames = {"group_1"})
@@ -85,15 +154,36 @@ public class CreateTaskAccTest extends AbstractAccTest {
         TaskService taskService = taskanaEngine.getTaskService();
         Task newTask = taskService.newTask("USER_1_1", "DOMAIN_A");
         newTask.setClassificationKey("L12010");
+        Map<String, String> customAttributesForCreate = createSimpleCustomProperties(27);
         newTask.addAttachment(createAttachment("DOCTYPE_DEFAULT",
             createObjectReference("COMPANY_A", "SYSTEM_B", "INSTANCE_B", "ArchiveId",
                 "12345678901234567890123456789012345678901234567890"),
-            "E-MAIL", "2018-01-15", createSimpleCustomProperties(3)));
+            "E-MAIL", "2018-01-15", customAttributesForCreate));
         newTask.setPrimaryObjRef(createObjectReference("COMPANY_A", "SYSTEM_A", "INSTANCE_A", "VNR", "1234567"));
         Task createdTask = taskService.createTask(newTask);
         assertNotNull(createdTask.getId());
         assertThat(createdTask.getCreator(), equalTo(CurrentUserContext.getUserid()));
 
+        // verify that the database content is as expected
+        TaskanaEngineProxyForTest engineProxy = new TaskanaEngineProxyForTest((TaskanaEngineImpl) taskanaEngine);
+        try {
+            SqlSession session = engineProxy.getSqlSession();
+            AttachmentMapper mapper = session.getMapper(AttachmentMapper.class);
+            engineProxy.openConnection();
+            String customProperties = mapper.getCustomAttributesAsString(createdTask.getAttachments().get(0).getId());
+            assertTrue(customProperties.contains("\"Property_26\":\"Property Value of Property_26\""));
+            assertTrue(customProperties.contains("\"Property_25\":\"Property Value of Property_25\""));
+            assertTrue(customProperties.contains("\"Property_21\":\"Property Value of Property_21\""));
+            assertTrue(customProperties.contains("\"Property_19\":\"Property Value of Property_19\""));
+            assertTrue(customProperties.contains("\"Property_16\":\"Property Value of Property_16\""));
+            assertTrue(customProperties.contains("\"Property_12\":\"Property Value of Property_12\""));
+            assertTrue(customProperties.contains("\"Property_11\":\"Property Value of Property_11\""));
+            assertTrue(customProperties.contains("\"Property_7\":\"Property Value of Property_7\""));
+            assertTrue(customProperties.contains("\"Property_6\":\"Property Value of Property_6\""));
+        } finally {
+            engineProxy.returnConnection();
+        }
+
         Task readTask = taskService.getTask(createdTask.getId());
         assertNotNull(readTask);
         assertThat(readTask.getCreator(), equalTo(CurrentUserContext.getUserid()));
@@ -104,6 +194,10 @@ public class CreateTaskAccTest extends AbstractAccTest {
         assertEquals(readTask.getAttachments().get(0).getCreated(), readTask.getAttachments().get(0).getModified());
         assertNotNull(readTask.getAttachments().get(0).getClassificationSummary());
         assertNotNull(readTask.getAttachments().get(0).getObjectReference());
+        // verify that the map is correctly retrieved from the database
+        Map<String, String> customAttributesFromDb = readTask.getAttachments().get(0).getCustomAttributes();
+        assertNotNull(customAttributesFromDb);
+        assertTrue(customAttributesFromDb.equals(customAttributesForCreate));
     }
 
     @WithAccessId(