Adding DataAccessLayerException to wrap SQLException in dashboard analytics feature

components/device-mgt/org.wso2.carbon.device.mgt.analytics.dashboard/src/main/java/org/wso2/carbon/device/mgt/analytics/dashboard/GadgetDataService.java

@@ -18,11 +18,13 @@
 
 package org.wso2.carbon.device.mgt.analytics.dashboard;
 
-import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.*;
+import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.DetailedDeviceEntry;
+import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.DeviceCountByGroupEntry;
+import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.FilterSet;
+import org.wso2.carbon.device.mgt.analytics.dashboard.dao.exception.DataAccessLayerException;
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.exception.InvalidParameterValueException;
 import org.wso2.carbon.device.mgt.common.PaginationResult;
 
-import java.sql.SQLException;
 import java.util.List;
 
 /**
@@ -31,56 +33,57 @@ import java.util.List;
 public interface GadgetDataService {
 
     @SuppressWarnings("unused")
-    DeviceCountByGroupEntry getDeviceCount(FilterSet filterSet) throws InvalidParameterValueException, SQLException;
+    DeviceCountByGroupEntry getDeviceCount(FilterSet filterSet)
+                            throws InvalidParameterValueException, DataAccessLayerException;
 
     @SuppressWarnings("unused")
     DeviceCountByGroupEntry getFeatureNonCompliantDeviceCount(String nonCompliantFeatureCode,
-                                           FilterSet filterSet) throws InvalidParameterValueException, SQLException;
+                            FilterSet filterSet) throws InvalidParameterValueException, DataAccessLayerException;
 
     @SuppressWarnings("unused")
-    DeviceCountByGroupEntry getTotalDeviceCount() throws SQLException;
+    DeviceCountByGroupEntry getTotalDeviceCount() throws DataAccessLayerException;
 
     @SuppressWarnings("unused")
-    List<DeviceCountByGroupEntry> getDeviceCountsByConnectivityStatuses() throws SQLException;
+    List<DeviceCountByGroupEntry> getDeviceCountsByConnectivityStatuses() throws DataAccessLayerException;
 
     @SuppressWarnings("unused")
-    List<DeviceCountByGroupEntry> getDeviceCountsByPotentialVulnerabilities() throws SQLException;
+    List<DeviceCountByGroupEntry> getDeviceCountsByPotentialVulnerabilities() throws DataAccessLayerException;
 
     @SuppressWarnings("unused")
     PaginationResult getNonCompliantDeviceCountsByFeatures(int startIndex, int resultCount)
-                                                           throws InvalidParameterValueException, SQLException;
+                                                       throws InvalidParameterValueException, DataAccessLayerException;
 
     @SuppressWarnings("unused")
     List<DeviceCountByGroupEntry> getDeviceCountsByPlatforms(FilterSet filterSet)
-                                          throws InvalidParameterValueException, SQLException;
+                                                       throws InvalidParameterValueException, DataAccessLayerException;
 
     @SuppressWarnings("unused")
     List<DeviceCountByGroupEntry> getFeatureNonCompliantDeviceCountsByPlatforms(String nonCompliantFeatureCode,
-                                          FilterSet filterSet) throws InvalidParameterValueException, SQLException;
+                                  FilterSet filterSet) throws InvalidParameterValueException, DataAccessLayerException;
 
     @SuppressWarnings("unused")
     List<DeviceCountByGroupEntry> getDeviceCountsByOwnershipTypes(FilterSet filterSet)
-                                          throws InvalidParameterValueException, SQLException;
+                                                       throws InvalidParameterValueException, DataAccessLayerException;
 
     @SuppressWarnings("unused")
     List<DeviceCountByGroupEntry> getFeatureNonCompliantDeviceCountsByOwnershipTypes(String nonCompliantFeatureCode,
-                                          FilterSet filterSet) throws InvalidParameterValueException, SQLException;
+                                  FilterSet filterSet) throws InvalidParameterValueException, DataAccessLayerException;
 
     @SuppressWarnings("unused")
     PaginationResult getDevicesWithDetails(FilterSet filterSet, int startIndex, int resultCount)
-                                                   throws InvalidParameterValueException, SQLException;
+                                                       throws InvalidParameterValueException, DataAccessLayerException;
 
     @SuppressWarnings("unused")
     PaginationResult getFeatureNonCompliantDevicesWithDetails(String nonCompliantFeatureCode,
                                                    FilterSet filterSet, int startIndex, int resultCount)
-                                                               throws InvalidParameterValueException, SQLException;
+                                                       throws InvalidParameterValueException, DataAccessLayerException;
 
     @SuppressWarnings("unused")
     List<DetailedDeviceEntry> getDevicesWithDetails(FilterSet filterSet)
-                                                    throws InvalidParameterValueException, SQLException;
+                                                       throws InvalidParameterValueException, DataAccessLayerException;
 
     @SuppressWarnings("unused")
     List<DetailedDeviceEntry> getFeatureNonCompliantDevicesWithDetails(String nonCompliantFeatureCode,
-                                          FilterSet filterSet) throws InvalidParameterValueException, SQLException;
+                                  FilterSet filterSet) throws InvalidParameterValueException, DataAccessLayerException;
 
 }

components/device-mgt/org.wso2.carbon.device.mgt.analytics.dashboard/src/main/java/org/wso2/carbon/device/mgt/analytics/dashboard/dao/AbstractGadgetDataServiceDAO.java

@@ -22,6 +22,7 @@ import org.wso2.carbon.context.PrivilegedCarbonContext;
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.DetailedDeviceEntry;
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.DeviceCountByGroupEntry;
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.FilterSet;
+import org.wso2.carbon.device.mgt.analytics.dashboard.dao.exception.DataAccessLayerException;
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.exception.InvalidParameterValueException;
 import org.wso2.carbon.device.mgt.core.dao.util.DeviceManagementDAOUtil;
 
@@ -37,7 +38,7 @@ import java.util.Map;
 public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceDAO {
 
     @Override
-    public DeviceCountByGroupEntry getTotalDeviceCount() throws SQLException {
+    public DeviceCountByGroupEntry getTotalDeviceCount() throws DataAccessLayerException {
         int totalDeviceCount;
         try {
             totalDeviceCount = this.getFilteredDeviceCount(null);
@@ -55,7 +56,7 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
 
     @Override
     public DeviceCountByGroupEntry getDeviceCount(FilterSet filterSet)
-                                                  throws InvalidParameterValueException, SQLException {
+                                                  throws InvalidParameterValueException, DataAccessLayerException {
 
         int filteredDeviceCount = this.getFilteredDeviceCount(filterSet);
 
@@ -67,7 +68,8 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
         return deviceCountByGroupEntry;
     }
 
-    private int getFilteredDeviceCount(FilterSet filterSet) throws InvalidParameterValueException, SQLException {
+    private int getFilteredDeviceCount(FilterSet filterSet)
+            throws InvalidParameterValueException, DataAccessLayerException {
 
         Map<String, Object> filters = this.extractDatabaseFiltersFromBean(filterSet);
 
@@ -106,6 +108,9 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
             while (rs.next()) {
                 filteredDeviceCount = rs.getInt("DEVICE_COUNT");
             }
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in either getting database connection, " +
+                "running SQL query or fetching results.", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }
@@ -114,7 +119,7 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
 
     @Override
     public DeviceCountByGroupEntry getFeatureNonCompliantDeviceCount(String nonCompliantFeatureCode,
-                                             FilterSet filterSet) throws InvalidParameterValueException, SQLException {
+                                 FilterSet filterSet) throws InvalidParameterValueException, DataAccessLayerException {
 
         if (nonCompliantFeatureCode == null || nonCompliantFeatureCode.isEmpty()) {
             throw new InvalidParameterValueException("Non-compliant feature code should not be either null or empty.");
@@ -159,6 +164,9 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
             while (rs.next()) {
                 filteredDeviceCount = rs.getInt("DEVICE_COUNT");
             }
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in either getting database connection, " +
+                "running SQL query or fetching results.", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }
@@ -172,7 +180,7 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
     }
 
     @Override
-    public List<DeviceCountByGroupEntry> getDeviceCountsByConnectivityStatuses() throws SQLException {
+    public List<DeviceCountByGroupEntry> getDeviceCountsByConnectivityStatuses() throws DataAccessLayerException {
         Connection con;
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -196,6 +204,9 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
                 deviceCountByConnectivityStatus.setDeviceCount(rs.getInt("DEVICE_COUNT"));
                 deviceCountsByConnectivityStatuses.add(deviceCountByConnectivityStatus);
             }
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in either getting database connection, " +
+                "running SQL query or fetching results.", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }
@@ -203,7 +214,7 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
     }
 
     @Override
-    public List<DeviceCountByGroupEntry> getDeviceCountsByPotentialVulnerabilities() throws SQLException {
+    public List<DeviceCountByGroupEntry> getDeviceCountsByPotentialVulnerabilities() throws DataAccessLayerException {
         // getting non-compliant device count
         DeviceCountByGroupEntry nonCompliantDeviceCount = new DeviceCountByGroupEntry();
         nonCompliantDeviceCount.setGroup(GadgetDataServiceDAOConstants.PotentialVulnerability.NON_COMPLIANT);
@@ -223,7 +234,7 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
         return deviceCountsByPotentialVulnerabilities;
     }
 
-    private int getNonCompliantDeviceCount() throws SQLException {
+    private int getNonCompliantDeviceCount() throws DataAccessLayerException {
         FilterSet filterSet = new FilterSet();
         filterSet.setPotentialVulnerability(GadgetDataServiceDAOConstants.PotentialVulnerability.NON_COMPLIANT);
         try {
@@ -233,7 +244,7 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
         }
     }
 
-    private int getUnmonitoredDeviceCount() throws SQLException {
+    private int getUnmonitoredDeviceCount() throws DataAccessLayerException {
         FilterSet filterSet = new FilterSet();
         filterSet.setPotentialVulnerability(GadgetDataServiceDAOConstants.PotentialVulnerability.UNMONITORED);
         try {
@@ -245,7 +256,7 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
 
     @Override
     public List<DeviceCountByGroupEntry> getDeviceCountsByPlatforms(FilterSet filterSet)
-                                                           throws InvalidParameterValueException, SQLException {
+                                                     throws InvalidParameterValueException, DataAccessLayerException {
 
         Map<String, Object> filters = this.extractDatabaseFiltersFromBean(filterSet);
 
@@ -291,6 +302,9 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
                 filteredDeviceCountByPlatform.setDeviceCount(rs.getInt("DEVICE_COUNT"));
                 filteredDeviceCountsByPlatforms.add(filteredDeviceCountByPlatform);
             }
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in either getting database connection, " +
+                "running SQL query or fetching results.", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }
@@ -300,7 +314,7 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
     @Override
     public List<DeviceCountByGroupEntry>
                          getFeatureNonCompliantDeviceCountsByPlatforms(String nonCompliantFeatureCode,
-                                             FilterSet filterSet) throws InvalidParameterValueException, SQLException {
+                                 FilterSet filterSet) throws InvalidParameterValueException, DataAccessLayerException {
 
         if (nonCompliantFeatureCode == null || nonCompliantFeatureCode.isEmpty()) {
             throw new InvalidParameterValueException("Non-compliant feature code should not be either null or empty.");
@@ -351,6 +365,9 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
                 filteredDeviceCountByPlatform.setDeviceCount(rs.getInt("DEVICE_COUNT"));
                 filteredDeviceCountsByPlatforms.add(filteredDeviceCountByPlatform);
             }
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in either getting database connection, " +
+                "running SQL query or fetching results.", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }
@@ -359,7 +376,7 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
 
     @Override
     public List<DeviceCountByGroupEntry> getDeviceCountsByOwnershipTypes(FilterSet filterSet)
-                                                                throws InvalidParameterValueException, SQLException {
+                                                     throws InvalidParameterValueException, DataAccessLayerException {
 
         Map<String, Object> filters = this.extractDatabaseFiltersFromBean(filterSet);
 
@@ -405,6 +422,9 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
                 filteredDeviceCountByOwnershipType.setDeviceCount(rs.getInt("DEVICE_COUNT"));
                 filteredDeviceCountsByOwnershipTypes.add(filteredDeviceCountByOwnershipType);
             }
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in either getting database connection, " +
+                "running SQL query or fetching results.", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }
@@ -414,7 +434,7 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
     @Override
     public List<DeviceCountByGroupEntry>
                   getFeatureNonCompliantDeviceCountsByOwnershipTypes(String nonCompliantFeatureCode,
-                                             FilterSet filterSet) throws InvalidParameterValueException, SQLException {
+                                 FilterSet filterSet) throws InvalidParameterValueException, DataAccessLayerException {
 
         if (nonCompliantFeatureCode == null || nonCompliantFeatureCode.isEmpty()) {
             throw new InvalidParameterValueException("Non-compliant feature code should not be either null or empty.");
@@ -465,6 +485,9 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
                 filteredDeviceCountByOwnershipType.setDeviceCount(rs.getInt("DEVICE_COUNT"));
                 filteredDeviceCountsByOwnershipTypes.add(filteredDeviceCountByOwnershipType);
             }
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in either getting database connection, " +
+                "running SQL query or fetching results.", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }
@@ -473,7 +496,7 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
 
     @Override
     public List<DetailedDeviceEntry> getDevicesWithDetails(FilterSet filterSet)
-                                                           throws InvalidParameterValueException, SQLException {
+                                     throws InvalidParameterValueException, DataAccessLayerException {
 
         Map<String, Object> filters = this.extractDatabaseFiltersFromBean(filterSet);
 
@@ -521,6 +544,9 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
                 filteredDeviceWithDetails.setConnectivityStatus(rs.getString("CONNECTIVITY_STATUS"));
                 filteredDevicesWithDetails.add(filteredDeviceWithDetails);
             }
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in either getting database connection, " +
+                "running SQL query or fetching results.", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }
@@ -529,7 +555,7 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
 
     @Override
     public List<DetailedDeviceEntry> getFeatureNonCompliantDevicesWithDetails(String nonCompliantFeatureCode,
-                                             FilterSet filterSet) throws InvalidParameterValueException, SQLException {
+                                 FilterSet filterSet) throws InvalidParameterValueException, DataAccessLayerException {
 
         if (nonCompliantFeatureCode == null || nonCompliantFeatureCode.isEmpty()) {
             throw new InvalidParameterValueException("Non-compliant feature code should not be either null or empty.");
@@ -582,6 +608,9 @@ public abstract class AbstractGadgetDataServiceDAO implements GadgetDataServiceD
                 filteredDeviceWithDetails.setConnectivityStatus(rs.getString("CONNECTIVITY_STATUS"));
                 filteredDevicesWithDetails.add(filteredDeviceWithDetails);
             }
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in either getting database connection, " +
+                "running SQL query or fetching results.", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }

components/device-mgt/org.wso2.carbon.device.mgt.analytics.dashboard/src/main/java/org/wso2/carbon/device/mgt/analytics/dashboard/dao/GadgetDataServiceDAO.java

@@ -18,56 +18,67 @@
 
 package org.wso2.carbon.device.mgt.analytics.dashboard.dao;
 
-import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.*;
+import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.DetailedDeviceEntry;
+import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.DeviceCountByGroupEntry;
+import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.FilterSet;
+import org.wso2.carbon.device.mgt.analytics.dashboard.dao.exception.DataAccessLayerException;
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.exception.InvalidParameterValueException;
 import org.wso2.carbon.device.mgt.common.PaginationResult;
 
-import java.sql.SQLException;
 import java.util.List;
 
 public interface GadgetDataServiceDAO {
 
-    DeviceCountByGroupEntry getDeviceCount(FilterSet filterSet) throws InvalidParameterValueException, SQLException;
+    /**
+     * This method is used to get device count based on a defined filter set.
+     * @param filterSet An abstract representation of possible filtering options.
+     *                  if this value is simply "null" or no values are set for the defined filtering options,
+     *                  this method would return total device count in the system
+     *                  wrapped with in the defined return format.
+     * @return An object of type DeviceCountByGroupEntry.
+     * @throws InvalidParameterValueException This can occur if and only if potentialVulnerability value of filterSet
+     *                                        is set with some value other than "NON_COMPLIANT" or "UNMONITORED".
+     * @throws DataAccessLayerException This can occur due to errors connecting to database,
+     *                                  executing SQL query and retrieving data.
+     */
+    DeviceCountByGroupEntry getDeviceCount(FilterSet filterSet)
+                                           throws InvalidParameterValueException, DataAccessLayerException;
 
     DeviceCountByGroupEntry getFeatureNonCompliantDeviceCount(String nonCompliantFeatureCode,
-                                           FilterSet filterSet) throws InvalidParameterValueException, SQLException;
+                                  FilterSet filterSet) throws InvalidParameterValueException, DataAccessLayerException;
 
-    /**
+    DeviceCountByGroupEntry getTotalDeviceCount() throws DataAccessLayerException;
-     * Method to get total device count from a particular tenant.
-     *
-     * @return Total device count.
-     */
-    DeviceCountByGroupEntry getTotalDeviceCount() throws SQLException;
 
-    List<DeviceCountByGroupEntry> getDeviceCountsByConnectivityStatuses() throws SQLException;
+    List<DeviceCountByGroupEntry> getDeviceCountsByConnectivityStatuses() throws DataAccessLayerException;
 
-    List<DeviceCountByGroupEntry> getDeviceCountsByPotentialVulnerabilities() throws SQLException;
+    List<DeviceCountByGroupEntry> getDeviceCountsByPotentialVulnerabilities() throws DataAccessLayerException;
 
     PaginationResult getNonCompliantDeviceCountsByFeatures(int startIndex, int resultCount)
-                                          throws InvalidParameterValueException, SQLException;
+                                          throws InvalidParameterValueException, DataAccessLayerException;
 
     List<DeviceCountByGroupEntry> getDeviceCountsByPlatforms(FilterSet filterSet)
-                                          throws InvalidParameterValueException, SQLException;
+                                          throws InvalidParameterValueException, DataAccessLayerException;
 
     List<DeviceCountByGroupEntry> getFeatureNonCompliantDeviceCountsByPlatforms(String nonCompliantFeatureCode,
-                                          FilterSet filterSet) throws InvalidParameterValueException, SQLException;
+                                  FilterSet filterSet) throws InvalidParameterValueException, DataAccessLayerException;
 
     List<DeviceCountByGroupEntry> getDeviceCountsByOwnershipTypes(FilterSet filterSet)
-                                          throws InvalidParameterValueException, SQLException;
+                                          throws InvalidParameterValueException, DataAccessLayerException;
 
     List<DeviceCountByGroupEntry> getFeatureNonCompliantDeviceCountsByOwnershipTypes(String nonCompliantFeatureCode,
-                                          FilterSet filterSet) throws InvalidParameterValueException, SQLException;
+                                  FilterSet filterSet) throws InvalidParameterValueException, DataAccessLayerException;
 
     PaginationResult getDevicesWithDetails(FilterSet filterSet, int startIndex, int resultCount)
-                                          throws InvalidParameterValueException, SQLException;
+                                           throws InvalidParameterValueException, DataAccessLayerException;
 
     PaginationResult getFeatureNonCompliantDevicesWithDetails(String nonCompliantFeatureCode,
-         FilterSet filterSet, int startIndex, int resultCount) throws InvalidParameterValueException, SQLException;
+                                                 FilterSet filterSet, int startIndex, int resultCount)
+                                                       throws InvalidParameterValueException, DataAccessLayerException;
 
     List<DetailedDeviceEntry> getDevicesWithDetails(FilterSet filterSet)
-                                          throws InvalidParameterValueException, SQLException;
+                                           throws InvalidParameterValueException, DataAccessLayerException;
 
     List<DetailedDeviceEntry> getFeatureNonCompliantDevicesWithDetails(String nonCompliantFeatureCode,
-                                          FilterSet filterSet) throws InvalidParameterValueException, SQLException;
+                                  FilterSet filterSet) throws InvalidParameterValueException, DataAccessLayerException;
 
 }

components/device-mgt/org.wso2.carbon.device.mgt.analytics.dashboard/src/main/java/org/wso2/carbon/device/mgt/analytics/dashboard/dao/GadgetDataServiceDAOFactory.java

@@ -90,7 +90,11 @@ public class GadgetDataServiceDAOFactory {
                 "this particular thread. Therefore, calling 'beginTransaction/openConnection' while another " +
                     "transaction is already active is a sign of improper transaction handling.");
         }
+        try {
             conn = dataSource.getConnection();
+        } catch (SQLException e) {
+
+        }
         currentConnection.set(conn);
     }
 
@@ -130,7 +134,7 @@ public class GadgetDataServiceDAOFactory {
         DataSource dataSource = null;
         if (config == null) {
             throw new RuntimeException(
-                "Device Management Repository data source configuration " + "is null and " +
+                "Device Management Repository data source configuration is null and " +
                     "thus, is not initialized.");
         }
         JNDILookupDefinition jndiConfig = config.getJndiLookupDefinition();

components/device-mgt/org.wso2.carbon.device.mgt.analytics.dashboard/src/main/java/org/wso2/carbon/device/mgt/analytics/dashboard/dao/exception/DataAccessLayerException.java

@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2016, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
+ *
+ * WSO2 Inc. licenses this file to you under the Apache License,
+ * Version 2.0 (the "License"); you may not use this file except
+ * in compliance with the License.
+ * you may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.wso2.carbon.device.mgt.analytics.dashboard.dao.exception;
+
+/**
+ * Custom exception class for communicating data access layer issues
+ * relevant to Gadget Data Service DAO layer.
+ * (In this particular instance, SQL exceptions related to database access).
+ */
+public class DataAccessLayerException extends Exception {
+
+    private String errorMessage;
+    private static final long serialVersionUID = 2021891706072918864L;
+
+    /**
+     * Constructs a new exception with the specific error message and nested exception.
+     * @param errorMessage specific error message.
+     * @param nestedException Nested exception.
+     */
+    @SuppressWarnings("unused")
+    public DataAccessLayerException(String errorMessage, Exception nestedException) {
+        super(errorMessage, nestedException);
+        setErrorMessage(errorMessage);
+    }
+
+    /**
+     * Constructs a new exception with the specific error message and cause.
+     * @param errorMessage Specific error message.
+     * @param cause Cause of this exception.
+     */
+    @SuppressWarnings("unused")
+    public DataAccessLayerException(String errorMessage, Throwable cause) {
+        super(errorMessage, cause);
+        setErrorMessage(errorMessage);
+    }
+
+    /**
+     * Constructs a new exception with the specific error message.
+     * @param errorMessage Specific error message.
+     */
+    public DataAccessLayerException(String errorMessage) {
+        super(errorMessage);
+        setErrorMessage(errorMessage);
+    }
+
+    /**
+     * Constructs a new exception with the specific error message and cause.
+     * @param cause Cause of this exception.
+     */
+    @SuppressWarnings("unused")
+    public DataAccessLayerException(Throwable cause) {
+        super(cause);
+    }
+
+    @SuppressWarnings("unused")
+    public String getErrorMessage() {
+        return errorMessage;
+    }
+
+    public void setErrorMessage(String errorMessage) {
+        this.errorMessage = errorMessage;
+    }
+
+}

components/device-mgt/org.wso2.carbon.device.mgt.analytics.dashboard/src/main/java/org/wso2/carbon/device/mgt/analytics/dashboard/dao/exception/InvalidParameterValueException.java

@@ -29,7 +29,6 @@ public class InvalidParameterValueException extends Exception {
 
     /**
      * Constructs a new exception with the specific error message and nested exception.
-     *
      * @param errorMessage specific error message.
      * @param nestedException Nested exception.
      */
@@ -41,7 +40,6 @@ public class InvalidParameterValueException extends Exception {
 
     /**
      * Constructs a new exception with the specific error message and cause.
-     *
      * @param errorMessage Specific error message.
      * @param cause Cause of this exception.
      */
@@ -53,7 +51,6 @@ public class InvalidParameterValueException extends Exception {
 
     /**
      * Constructs a new exception with the specific error message.
-     *
      * @param errorMessage Specific error message.
      */
     public InvalidParameterValueException(String errorMessage) {
@@ -63,7 +60,6 @@ public class InvalidParameterValueException extends Exception {
 
     /**
      * Constructs a new exception with the specific error message and cause.
-     *
      * @param cause Cause of this exception.
      */
     @SuppressWarnings("unused")

components/device-mgt/org.wso2.carbon.device.mgt.analytics.dashboard/src/main/java/org/wso2/carbon/device/mgt/analytics/dashboard/dao/impl/GenericGadgetDataServiceDAOImpl.java

@@ -23,6 +23,7 @@ import org.wso2.carbon.device.mgt.analytics.dashboard.dao.AbstractGadgetDataServ
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.DetailedDeviceEntry;
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.DeviceCountByGroupEntry;
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.FilterSet;
+import org.wso2.carbon.device.mgt.analytics.dashboard.dao.exception.DataAccessLayerException;
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.exception.InvalidParameterValueException;
 import org.wso2.carbon.device.mgt.common.PaginationResult;
 import org.wso2.carbon.device.mgt.core.dao.util.DeviceManagementDAOUtil;
@@ -39,7 +40,7 @@ public class GenericGadgetDataServiceDAOImpl extends AbstractGadgetDataServiceDA
 
     @Override
     public PaginationResult getNonCompliantDeviceCountsByFeatures(int startIndex, int resultCount)
-                                                           throws InvalidParameterValueException, SQLException {
+                                                     throws InvalidParameterValueException, DataAccessLayerException {
 
         if (startIndex < 0) {
             throw new InvalidParameterValueException("Start index should be equal to 0 or greater than that.");
@@ -88,6 +89,9 @@ public class GenericGadgetDataServiceDAOImpl extends AbstractGadgetDataServiceDA
             while (rs.next()) {
                 totalRecordsCount = rs.getInt("NON_COMPLIANT_FEATURE_COUNT");
             }
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in either getting database connection, " +
+                "running SQL query or fetching results.", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }
@@ -99,7 +103,7 @@ public class GenericGadgetDataServiceDAOImpl extends AbstractGadgetDataServiceDA
 
     @Override
     public PaginationResult getDevicesWithDetails(FilterSet filterSet, int startIndex, int resultCount)
-                                                           throws InvalidParameterValueException, SQLException {
+                                                  throws InvalidParameterValueException, DataAccessLayerException {
 
         if (startIndex < 0) {
             throw new InvalidParameterValueException("Start index should be equal to 0 or greater than that.");
@@ -174,6 +178,9 @@ public class GenericGadgetDataServiceDAOImpl extends AbstractGadgetDataServiceDA
             while (rs.next()) {
                 totalRecordsCount = rs.getInt("DEVICE_COUNT");
             }
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in either getting database connection, " +
+                "running SQL query or fetching results.", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }
@@ -186,7 +193,7 @@ public class GenericGadgetDataServiceDAOImpl extends AbstractGadgetDataServiceDA
     @Override
     public PaginationResult getFeatureNonCompliantDevicesWithDetails(String nonCompliantFeatureCode,
                                                    FilterSet filterSet, int startIndex, int resultCount)
-                                                                  throws InvalidParameterValueException, SQLException {
+                                                      throws InvalidParameterValueException, DataAccessLayerException {
 
         if (nonCompliantFeatureCode == null || nonCompliantFeatureCode.isEmpty()) {
             throw new InvalidParameterValueException("Non-compliant feature code should not be either null or empty.");
@@ -269,6 +276,9 @@ public class GenericGadgetDataServiceDAOImpl extends AbstractGadgetDataServiceDA
             while (rs.next()) {
                 totalRecordsCount = rs.getInt("DEVICE_COUNT");
             }
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in either getting database connection, " +
+                "running SQL query or fetching results.", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }

components/device-mgt/org.wso2.carbon.device.mgt.analytics.dashboard/src/main/java/org/wso2/carbon/device/mgt/analytics/dashboard/dao/impl/MSSQLGadgetDataServiceDAOImpl.java

@@ -23,6 +23,7 @@ import org.wso2.carbon.device.mgt.analytics.dashboard.dao.AbstractGadgetDataServ
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.DetailedDeviceEntry;
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.DeviceCountByGroupEntry;
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.FilterSet;
+import org.wso2.carbon.device.mgt.analytics.dashboard.dao.exception.DataAccessLayerException;
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.exception.InvalidParameterValueException;
 import org.wso2.carbon.device.mgt.common.PaginationResult;
 import org.wso2.carbon.device.mgt.core.dao.util.DeviceManagementDAOUtil;
@@ -39,7 +40,7 @@ public class MSSQLGadgetDataServiceDAOImpl extends AbstractGadgetDataServiceDAO
 
     @Override
     public PaginationResult getNonCompliantDeviceCountsByFeatures(int startIndex, int resultCount)
-                                                           throws InvalidParameterValueException, SQLException {
+                                                     throws InvalidParameterValueException, DataAccessLayerException {
 
         if (startIndex < 0) {
             throw new InvalidParameterValueException("Start index should be equal to 0 or greater than that.");
@@ -89,6 +90,9 @@ public class MSSQLGadgetDataServiceDAOImpl extends AbstractGadgetDataServiceDAO
             while (rs.next()) {
                 totalRecordsCount = rs.getInt("NON_COMPLIANT_FEATURE_COUNT");
             }
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in either getting database connection, " +
+                "running SQL query or fetching results.", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }
@@ -100,7 +104,7 @@ public class MSSQLGadgetDataServiceDAOImpl extends AbstractGadgetDataServiceDAO
 
     @Override
     public PaginationResult getDevicesWithDetails(FilterSet filterSet, int startIndex, int resultCount)
-                                                           throws InvalidParameterValueException, SQLException {
+                                                  throws InvalidParameterValueException, DataAccessLayerException {
 
         if (startIndex < 0) {
             throw new InvalidParameterValueException("Start index should be equal to 0 or greater than that.");
@@ -176,6 +180,9 @@ public class MSSQLGadgetDataServiceDAOImpl extends AbstractGadgetDataServiceDAO
             while (rs.next()) {
                 totalRecordsCount = rs.getInt("DEVICE_COUNT");
             }
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in either getting database connection, " +
+                "running SQL query or fetching results.", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }
@@ -188,7 +195,7 @@ public class MSSQLGadgetDataServiceDAOImpl extends AbstractGadgetDataServiceDAO
     @Override
     public PaginationResult getFeatureNonCompliantDevicesWithDetails(String nonCompliantFeatureCode,
                                                       FilterSet filterSet, int startIndex, int resultCount)
-                                                                 throws InvalidParameterValueException, SQLException {
+                                                      throws InvalidParameterValueException, DataAccessLayerException {
 
         if (nonCompliantFeatureCode == null || nonCompliantFeatureCode.isEmpty()) {
             throw new InvalidParameterValueException("Non-compliant feature code should not be either null or empty.");
@@ -271,6 +278,9 @@ public class MSSQLGadgetDataServiceDAOImpl extends AbstractGadgetDataServiceDAO
             while (rs.next()) {
                 totalRecordsCount = rs.getInt("DEVICE_COUNT");
             }
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in either getting database connection, " +
+                "running SQL query or fetching results.", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }

components/device-mgt/org.wso2.carbon.device.mgt.analytics.dashboard/src/main/java/org/wso2/carbon/device/mgt/analytics/dashboard/dao/impl/OracleGadgetDataServiceDAOImpl.java

@@ -23,6 +23,7 @@ import org.wso2.carbon.device.mgt.analytics.dashboard.dao.AbstractGadgetDataServ
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.DetailedDeviceEntry;
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.DeviceCountByGroupEntry;
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.FilterSet;
+import org.wso2.carbon.device.mgt.analytics.dashboard.dao.exception.DataAccessLayerException;
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.exception.InvalidParameterValueException;
 import org.wso2.carbon.device.mgt.common.PaginationResult;
 import org.wso2.carbon.device.mgt.core.dao.util.DeviceManagementDAOUtil;
@@ -39,7 +40,7 @@ public class OracleGadgetDataServiceDAOImpl extends AbstractGadgetDataServiceDAO
 
     @Override
     public PaginationResult getNonCompliantDeviceCountsByFeatures(int startIndex, int resultCount)
-                                                           throws InvalidParameterValueException, SQLException {
+                                                     throws InvalidParameterValueException, DataAccessLayerException {
 
         if (startIndex < 0) {
             throw new InvalidParameterValueException("Start index should be equal to 0 or greater than that.");
@@ -89,6 +90,9 @@ public class OracleGadgetDataServiceDAOImpl extends AbstractGadgetDataServiceDAO
             while (rs.next()) {
                 totalRecordsCount = rs.getInt("NON_COMPLIANT_FEATURE_COUNT");
             }
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in either getting database connection, " +
+                "running SQL query or fetching results.", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }
@@ -100,7 +104,7 @@ public class OracleGadgetDataServiceDAOImpl extends AbstractGadgetDataServiceDAO
 
     @Override
     public PaginationResult getDevicesWithDetails(FilterSet filterSet, int startIndex, int resultCount)
-                                                           throws InvalidParameterValueException, SQLException {
+                                                  throws InvalidParameterValueException, DataAccessLayerException {
 
         if (startIndex < 0) {
             throw new InvalidParameterValueException("Start index should be equal to 0 or greater than that.");
@@ -176,6 +180,9 @@ public class OracleGadgetDataServiceDAOImpl extends AbstractGadgetDataServiceDAO
             while (rs.next()) {
                 totalRecordsCount = rs.getInt("DEVICE_COUNT");
             }
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in either getting database connection, " +
+                "running SQL query or fetching results.", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }
@@ -188,7 +195,7 @@ public class OracleGadgetDataServiceDAOImpl extends AbstractGadgetDataServiceDAO
     @Override
     public PaginationResult getFeatureNonCompliantDevicesWithDetails(String nonCompliantFeatureCode,
                                                       FilterSet filterSet, int startIndex, int resultCount)
-                                                                  throws InvalidParameterValueException, SQLException {
+                                                      throws InvalidParameterValueException, DataAccessLayerException {
 
         if (nonCompliantFeatureCode == null || nonCompliantFeatureCode.isEmpty()) {
             throw new InvalidParameterValueException("Non-compliant feature code should not be either null or empty.");
@@ -271,6 +278,9 @@ public class OracleGadgetDataServiceDAOImpl extends AbstractGadgetDataServiceDAO
             while (rs.next()) {
                 totalRecordsCount = rs.getInt("DEVICE_COUNT");
             }
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in either getting database connection, " +
+                "running SQL query or fetching results.", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }

components/device-mgt/org.wso2.carbon.device.mgt.analytics.dashboard/src/main/java/org/wso2/carbon/device/mgt/analytics/dashboard/dao/impl/PostgreSQLGadgetDataServiceDAOImpl.java

@@ -23,6 +23,7 @@ import org.wso2.carbon.device.mgt.analytics.dashboard.dao.AbstractGadgetDataServ
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.DetailedDeviceEntry;
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.DeviceCountByGroupEntry;
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.FilterSet;
+import org.wso2.carbon.device.mgt.analytics.dashboard.dao.exception.DataAccessLayerException;
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.exception.InvalidParameterValueException;
 import org.wso2.carbon.device.mgt.common.PaginationResult;
 import org.wso2.carbon.device.mgt.core.dao.util.DeviceManagementDAOUtil;
@@ -39,7 +40,7 @@ public class PostgreSQLGadgetDataServiceDAOImpl extends AbstractGadgetDataServic
 
     @Override
     public PaginationResult getNonCompliantDeviceCountsByFeatures(int startIndex, int resultCount)
-                                                           throws InvalidParameterValueException, SQLException {
+                                                      throws InvalidParameterValueException, DataAccessLayerException {
 
         if (startIndex < 0) {
             throw new InvalidParameterValueException("Start index should be equal to 0 or greater than that.");
@@ -88,6 +89,9 @@ public class PostgreSQLGadgetDataServiceDAOImpl extends AbstractGadgetDataServic
             while (rs.next()) {
                 totalRecordsCount = rs.getInt("NON_COMPLIANT_FEATURE_COUNT");
             }
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in either getting database connection, " +
+                "running SQL query or fetching results.", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }
@@ -99,7 +103,7 @@ public class PostgreSQLGadgetDataServiceDAOImpl extends AbstractGadgetDataServic
 
     @Override
     public PaginationResult getDevicesWithDetails(FilterSet filterSet, int startIndex, int resultCount)
-                                                           throws InvalidParameterValueException, SQLException {
+                                                  throws InvalidParameterValueException, DataAccessLayerException {
 
         if (startIndex < 0) {
             throw new InvalidParameterValueException("Start index should be equal to 0 or greater than that.");
@@ -174,6 +178,9 @@ public class PostgreSQLGadgetDataServiceDAOImpl extends AbstractGadgetDataServic
             while (rs.next()) {
                 totalRecordsCount = rs.getInt("DEVICE_COUNT");
             }
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in either getting database connection, " +
+                "running SQL query or fetching results.", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }
@@ -186,7 +193,7 @@ public class PostgreSQLGadgetDataServiceDAOImpl extends AbstractGadgetDataServic
     @Override
     public PaginationResult getFeatureNonCompliantDevicesWithDetails(String nonCompliantFeatureCode,
                                                       FilterSet filterSet, int startIndex, int resultCount)
-                                                                  throws InvalidParameterValueException, SQLException {
+                                                      throws InvalidParameterValueException, DataAccessLayerException {
 
         if (nonCompliantFeatureCode == null || nonCompliantFeatureCode.isEmpty()) {
             throw new InvalidParameterValueException("Non-compliant feature code should not be either null or empty.");
@@ -269,6 +276,9 @@ public class PostgreSQLGadgetDataServiceDAOImpl extends AbstractGadgetDataServic
             while (rs.next()) {
                 totalRecordsCount = rs.getInt("DEVICE_COUNT");
             }
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in either getting database connection, " +
+                "running SQL query or fetching results.", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }

components/device-mgt/org.wso2.carbon.device.mgt.analytics.dashboard/src/main/java/org/wso2/carbon/device/mgt/analytics/dashboard/impl/GadgetDataServiceImpl.java

@@ -20,7 +20,10 @@ package org.wso2.carbon.device.mgt.analytics.dashboard.impl;
 
 import org.wso2.carbon.device.mgt.analytics.dashboard.GadgetDataService;
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.GadgetDataServiceDAOFactory;
-import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.*;
+import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.DetailedDeviceEntry;
+import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.DeviceCountByGroupEntry;
+import org.wso2.carbon.device.mgt.analytics.dashboard.dao.bean.FilterSet;
+import org.wso2.carbon.device.mgt.analytics.dashboard.dao.exception.DataAccessLayerException;
 import org.wso2.carbon.device.mgt.analytics.dashboard.dao.exception.InvalidParameterValueException;
 import org.wso2.carbon.device.mgt.common.PaginationResult;
 
@@ -33,11 +36,14 @@ import java.util.List;
 public class GadgetDataServiceImpl implements GadgetDataService {
 
     @Override
-    public DeviceCountByGroupEntry getDeviceCount(FilterSet filterSet) throws InvalidParameterValueException, SQLException {
+    public DeviceCountByGroupEntry getDeviceCount(FilterSet filterSet)
+                                                  throws InvalidParameterValueException, DataAccessLayerException {
         DeviceCountByGroupEntry filteredDeviceCount;
         try {
             GadgetDataServiceDAOFactory.openConnection();
             filteredDeviceCount = GadgetDataServiceDAOFactory.getGadgetDataServiceDAO().getDeviceCount(filterSet);
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in opening database connection.", e);
         } finally {
             GadgetDataServiceDAOFactory.closeConnection();
         }
@@ -45,13 +51,15 @@ public class GadgetDataServiceImpl implements GadgetDataService {
     }
 
     @Override
-    public DeviceCountByGroupEntry getFeatureNonCompliantDeviceCount(String nonCompliantFeatureCode, FilterSet filterSet)
+    public DeviceCountByGroupEntry getFeatureNonCompliantDeviceCount(String nonCompliantFeatureCode,
-                                                                  throws InvalidParameterValueException, SQLException {
+                             FilterSet filterSet) throws InvalidParameterValueException, DataAccessLayerException {
         DeviceCountByGroupEntry featureNonCompliantDeviceCount;
         try {
             GadgetDataServiceDAOFactory.openConnection();
             featureNonCompliantDeviceCount = GadgetDataServiceDAOFactory.
                 getGadgetDataServiceDAO().getFeatureNonCompliantDeviceCount(nonCompliantFeatureCode, filterSet);
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in opening database connection.", e);
         } finally {
             GadgetDataServiceDAOFactory.closeConnection();
         }
@@ -59,11 +67,13 @@ public class GadgetDataServiceImpl implements GadgetDataService {
     }
 
     @Override
-    public DeviceCountByGroupEntry getTotalDeviceCount() throws SQLException {
+    public DeviceCountByGroupEntry getTotalDeviceCount() throws DataAccessLayerException {
         DeviceCountByGroupEntry totalDeviceCount;
         try {
             GadgetDataServiceDAOFactory.openConnection();
             totalDeviceCount = GadgetDataServiceDAOFactory.getGadgetDataServiceDAO().getTotalDeviceCount();
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in opening database connection.", e);
         } finally {
             GadgetDataServiceDAOFactory.closeConnection();
         }
@@ -71,12 +81,14 @@ public class GadgetDataServiceImpl implements GadgetDataService {
     }
 
     @Override
-    public List<DeviceCountByGroupEntry> getDeviceCountsByConnectivityStatuses() throws SQLException {
+    public List<DeviceCountByGroupEntry> getDeviceCountsByConnectivityStatuses() throws DataAccessLayerException {
         List<DeviceCountByGroupEntry> deviceCountsByConnectivityStatuses;
         try {
             GadgetDataServiceDAOFactory.openConnection();
             deviceCountsByConnectivityStatuses = GadgetDataServiceDAOFactory.
                 getGadgetDataServiceDAO().getDeviceCountsByConnectivityStatuses();
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in opening database connection.", e);
         } finally {
             GadgetDataServiceDAOFactory.closeConnection();
         }
@@ -84,12 +96,14 @@ public class GadgetDataServiceImpl implements GadgetDataService {
     }
 
     @Override
-    public List<DeviceCountByGroupEntry> getDeviceCountsByPotentialVulnerabilities() throws SQLException {
+    public List<DeviceCountByGroupEntry> getDeviceCountsByPotentialVulnerabilities() throws DataAccessLayerException {
         List<DeviceCountByGroupEntry> deviceCountsByPotentialVulnerabilities;
         try {
             GadgetDataServiceDAOFactory.openConnection();
             deviceCountsByPotentialVulnerabilities = GadgetDataServiceDAOFactory.getGadgetDataServiceDAO().
                 getDeviceCountsByPotentialVulnerabilities();
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in opening database connection.", e);
         } finally {
             GadgetDataServiceDAOFactory.closeConnection();
         }
@@ -98,12 +112,14 @@ public class GadgetDataServiceImpl implements GadgetDataService {
 
     @Override
     public PaginationResult getNonCompliantDeviceCountsByFeatures(int startIndex, int resultCount)
-                                                                  throws SQLException, InvalidParameterValueException {
+                                                     throws InvalidParameterValueException, DataAccessLayerException {
         PaginationResult paginationResult;
         try {
             GadgetDataServiceDAOFactory.openConnection();
             paginationResult = GadgetDataServiceDAOFactory.getGadgetDataServiceDAO().
                 getNonCompliantDeviceCountsByFeatures(startIndex, resultCount);
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in opening database connection.", e);
         } finally {
             GadgetDataServiceDAOFactory.closeConnection();
         }
@@ -112,12 +128,14 @@ public class GadgetDataServiceImpl implements GadgetDataService {
 
     @Override
     public List<DeviceCountByGroupEntry> getDeviceCountsByPlatforms(FilterSet filterSet)
-                                                                  throws InvalidParameterValueException, SQLException {
+                                                     throws InvalidParameterValueException, DataAccessLayerException {
         List<DeviceCountByGroupEntry> deviceCountsByPlatforms;
         try {
             GadgetDataServiceDAOFactory.openConnection();
             deviceCountsByPlatforms = GadgetDataServiceDAOFactory.getGadgetDataServiceDAO().
                 getDeviceCountsByPlatforms(filterSet);
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in opening database connection.", e);
         } finally {
             GadgetDataServiceDAOFactory.closeConnection();
         }
@@ -126,12 +144,14 @@ public class GadgetDataServiceImpl implements GadgetDataService {
 
     @Override
     public List<DeviceCountByGroupEntry> getFeatureNonCompliantDeviceCountsByPlatforms(String nonCompliantFeatureCode,
-                                             FilterSet filterSet) throws InvalidParameterValueException, SQLException {
+                                 FilterSet filterSet) throws InvalidParameterValueException, DataAccessLayerException {
         List<DeviceCountByGroupEntry> featureNonCompliantDeviceCountsByPlatforms;
         try {
             GadgetDataServiceDAOFactory.openConnection();
             featureNonCompliantDeviceCountsByPlatforms = GadgetDataServiceDAOFactory.getGadgetDataServiceDAO().
                 getFeatureNonCompliantDeviceCountsByPlatforms(nonCompliantFeatureCode, filterSet);
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in opening database connection.", e);
         } finally {
             GadgetDataServiceDAOFactory.closeConnection();
         }
@@ -140,12 +160,14 @@ public class GadgetDataServiceImpl implements GadgetDataService {
 
     @Override
     public List<DeviceCountByGroupEntry> getDeviceCountsByOwnershipTypes(FilterSet filterSet)
-                                                                 throws InvalidParameterValueException, SQLException {
+                                                      throws InvalidParameterValueException, DataAccessLayerException {
         List<DeviceCountByGroupEntry> deviceCountsByOwnershipTypes;
         try {
             GadgetDataServiceDAOFactory.openConnection();
             deviceCountsByOwnershipTypes = GadgetDataServiceDAOFactory.getGadgetDataServiceDAO().
                 getDeviceCountsByOwnershipTypes(filterSet);
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in opening database connection.", e);
         } finally {
             GadgetDataServiceDAOFactory.closeConnection();
         }
@@ -155,12 +177,14 @@ public class GadgetDataServiceImpl implements GadgetDataService {
     @Override
     public List<DeviceCountByGroupEntry>
         getFeatureNonCompliantDeviceCountsByOwnershipTypes(String nonCompliantFeatureCode,
-                                            FilterSet filterSet) throws SQLException, InvalidParameterValueException {
+                                 FilterSet filterSet) throws InvalidParameterValueException, DataAccessLayerException {
         List<DeviceCountByGroupEntry> featureNonCompliantDeviceCountsByOwnershipTypes;
         try {
             GadgetDataServiceDAOFactory.openConnection();
             featureNonCompliantDeviceCountsByOwnershipTypes = GadgetDataServiceDAOFactory.getGadgetDataServiceDAO().
                 getFeatureNonCompliantDeviceCountsByOwnershipTypes(nonCompliantFeatureCode, filterSet);
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in opening database connection.", e);
         } finally {
             GadgetDataServiceDAOFactory.closeConnection();
         }
@@ -169,12 +193,14 @@ public class GadgetDataServiceImpl implements GadgetDataService {
 
     @Override
     public PaginationResult getDevicesWithDetails(FilterSet filterSet,
-                                int startIndex, int resultCount) throws InvalidParameterValueException, SQLException {
+                     int startIndex, int resultCount) throws InvalidParameterValueException, DataAccessLayerException {
         PaginationResult paginationResult;
         try {
             GadgetDataServiceDAOFactory.openConnection();
             paginationResult = GadgetDataServiceDAOFactory.getGadgetDataServiceDAO().
                 getDevicesWithDetails(filterSet, startIndex, resultCount);
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in opening database connection.", e);
         } finally {
             GadgetDataServiceDAOFactory.closeConnection();
         }
@@ -184,12 +210,14 @@ public class GadgetDataServiceImpl implements GadgetDataService {
     @Override
     public PaginationResult getFeatureNonCompliantDevicesWithDetails(String nonCompliantFeatureCode,
                                                       FilterSet filterSet, int startIndex, int resultCount)
-                                                                 throws InvalidParameterValueException, SQLException {
+                                                      throws InvalidParameterValueException, DataAccessLayerException {
         PaginationResult paginationResult;
         try {
             GadgetDataServiceDAOFactory.openConnection();
             paginationResult = GadgetDataServiceDAOFactory.getGadgetDataServiceDAO().
                 getFeatureNonCompliantDevicesWithDetails(nonCompliantFeatureCode, filterSet, startIndex, resultCount);
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in opening database connection.", e);
         } finally {
             GadgetDataServiceDAOFactory.closeConnection();
         }
@@ -198,12 +226,14 @@ public class GadgetDataServiceImpl implements GadgetDataService {
 
     @Override
     public List<DetailedDeviceEntry> getDevicesWithDetails(FilterSet filterSet)
-                                                           throws InvalidParameterValueException, SQLException {
+                                                      throws InvalidParameterValueException, DataAccessLayerException {
         List<DetailedDeviceEntry> devicesWithDetails;
         try {
             GadgetDataServiceDAOFactory.openConnection();
             devicesWithDetails = GadgetDataServiceDAOFactory.
                 getGadgetDataServiceDAO().getDevicesWithDetails(filterSet);
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in opening database connection.", e);
         } finally {
             GadgetDataServiceDAOFactory.closeConnection();
         }
@@ -212,12 +242,14 @@ public class GadgetDataServiceImpl implements GadgetDataService {
 
     @Override
     public List<DetailedDeviceEntry> getFeatureNonCompliantDevicesWithDetails(String nonCompliantFeatureCode,
-                                            FilterSet filterSet) throws InvalidParameterValueException, SQLException {
+                                 FilterSet filterSet) throws InvalidParameterValueException, DataAccessLayerException {
         List<DetailedDeviceEntry> featureNonCompliantDevicesWithDetails;
         try {
             GadgetDataServiceDAOFactory.openConnection();
             featureNonCompliantDevicesWithDetails = GadgetDataServiceDAOFactory.getGadgetDataServiceDAO().
                 getFeatureNonCompliantDevicesWithDetails(nonCompliantFeatureCode, filterSet);
+        } catch (SQLException e) {
+            throw new DataAccessLayerException("Error in opening database connection.", e);
         } finally {
             GadgetDataServiceDAOFactory.closeConnection();
         }