=== modified file 'dhis-2/dhis-api/src/main/java/org/hisp/dhis/dataelement/DataElementService.java'
--- dhis-2/dhis-api/src/main/java/org/hisp/dhis/dataelement/DataElementService.java	2015-03-13 15:48:26 +0000
+++ dhis-2/dhis-api/src/main/java/org/hisp/dhis/dataelement/DataElementService.java	2015-06-11 11:38:56 +0000
@@ -116,7 +116,7 @@
      * @return List of DataElements with a given key, or all dataelements if no
      *         match.
      */
-    Collection<DataElement> searchDataElementsByName( String key );
+    List<DataElement> searchDataElementsByName( String key );
 
     /**
      * Returns a DataElement with a given short name.
@@ -129,26 +129,26 @@
     /**
      * Returns all DataElements.
      *
-     * @return a collection of all DataElements, or an empty collection if there
+     * @return a list of all DataElements, or an empty collection if there
      *         are no DataElements.
      */
-    Collection<DataElement> getAllDataElements();
+    List<DataElement> getAllDataElements();
 
     /**
      * Returns all DataElements with corresponding identifiers. Returns all
      * DataElements if the given argument is null.
      *
      * @param identifiers the collection of identifiers.
-     * @return a collection of DataElements.
+     * @return a list of DataElements.
      */
-    Collection<DataElement> getDataElements( Collection<Integer> identifiers );
+    List<DataElement> getDataElements( Collection<Integer> identifiers );
 
     /**
      * Returns all DataElements with corresponding identifiers. Returns all
      * DataElements if the given argument is null.
      *
      * @param uids the collection of uids.
-     * @return a collection of DataElements.
+     * @return a list of DataElements.
      */
     List<DataElement> getDataElementsByUid( Collection<String> uids );
 
@@ -158,34 +158,34 @@
      *
      * @return all DataElements with types that are possible to aggregate.
      */
-    Collection<DataElement> getAggregateableDataElements();
+    List<DataElement> getAggregateableDataElements();
 
     /**
      * Returns all DataElements with a given aggregation operator.
      *
      * @param aggregationOperator the aggregation operator of the DataElements
      *                            to return.
-     * @return a collection of all DataElements with the given aggregation
+     * @return a list of all DataElements with the given aggregation
      *         operator, or an empty collection if no DataElements have the
      *         aggregation operator.
      */
-    Collection<DataElement> getDataElementsByAggregationOperator( String aggregationOperator );
-
-    /**
-     * Returns all DataElements with the given domain type.
-     *
-     * @param domainType the DataElementDomainType.
-     * @return all DataElements with the given domainType.
-     */
-    Collection<DataElement> getDataElementsByDomainType( DataElementDomain domainType );
-
-    /**
-     * Returns all DataElements with the given domain type.
-     *
-     * @param domainType the DataElementDomainType.
-     * @return all DataElements with the given domainType.
-     */
-    Collection<DataElement> getDataElementsByDomainType( DataElementDomain domainType, int first, int max );
+    List<DataElement> getDataElementsByAggregationOperator( String aggregationOperator );
+
+    /**
+     * Returns all DataElements with the given domain type.
+     *
+     * @param domainType the DataElementDomainType.
+     * @return all DataElements with the given domainType.
+     */
+    List<DataElement> getDataElementsByDomainType( DataElementDomain domainType );
+
+    /**
+     * Returns all DataElements with the given domain type.
+     *
+     * @param domainType the DataElementDomainType.
+     * @return all DataElements with the given domainType.
+     */
+    List<DataElement> getDataElementsByDomainType( DataElementDomain domainType, int first, int max );
 
     /**
      * Returns all DataElements with the given type.
@@ -194,15 +194,15 @@
      * @return all DataElements with the given type.
      */
 
-    Collection<DataElement> getDataElementsByType( String type );
+    List<DataElement> getDataElementsByType( String type );
 
     /**
      * Returns the DataElements with the given PeriodType.
      *
      * @param periodType the PeriodType.
-     * @return a Collection of DataElements.
+     * @return a list of DataElements.
      */
-    Collection<DataElement> getDataElementsByPeriodType( PeriodType periodType );
+    List<DataElement> getDataElementsByPeriodType( PeriodType periodType );
 
     /**
      * Returns all DataElements with the given category combo.
@@ -210,7 +210,7 @@
      * @param categoryCombo the DataElementCategoryCombo.
      * @return all DataElements with the given category combo.
      */
-    Collection<DataElement> getDataElementByCategoryCombo( DataElementCategoryCombo categoryCombo );
+    List<DataElement> getDataElementByCategoryCombo( DataElementCategoryCombo categoryCombo );
 
     /**
      * Returns a Map with DataElementCategoryCombo as key and a Collection of
@@ -239,28 +239,28 @@
      * @return all DataElements which are associated with one or more
      *         DataElementGroupSets.
      */
-    Collection<DataElement> getDataElementsWithGroupSets();
+    List<DataElement> getDataElementsWithGroupSets();
 
     /**
      * Returns all DataElements which are not member of any DataElementGroups.
      *
      * @return all DataElements which are not member of any DataElementGroups.
      */
-    Collection<DataElement> getDataElementsWithoutGroups();
+    List<DataElement> getDataElementsWithoutGroups();
 
     /**
      * Returns all DataElements which are not assigned to any DataSets.
      *
      * @return all DataElements which are not assigned to any DataSets.
      */
-    Collection<DataElement> getDataElementsWithoutDataSets();
+    List<DataElement> getDataElementsWithoutDataSets();
 
     /**
      * Returns all DataElements which are assigned to at least one DataSet.
      *
      * @return all DataElements which are assigned to at least one DataSet.
      */
-    Collection<DataElement> getDataElementsWithDataSets();
+    List<DataElement> getDataElementsWithDataSets();
 
     /**
      * Returns all DataElements which are assigned to any of the given DataSets.
@@ -268,7 +268,7 @@
      * @param dataSets the collection of DataSets.
      * @return all DataElements which are assigned to any of the given DataSets.
      */
-    Collection<DataElement> getDataElementsByDataSets( Collection<DataSet> dataSets );
+    List<DataElement> getDataElementsByDataSets( Collection<DataSet> dataSets );
 
     /**
      * Returns all DataElements which have the given aggregation level assigned.
@@ -276,13 +276,13 @@
      * @param aggregationLevel the aggregation level.
      * @return all DataElements which have the given aggregation level assigned.
      */
-    Collection<DataElement> getDataElementsByAggregationLevel( int aggregationLevel );
-
-    Collection<DataElement> getDataElementsLikeName( String name );
-
-    Collection<DataElement> getDataElementsBetween( int first, int max );
-
-    Collection<DataElement> getDataElementsBetweenByName( String name, int first, int max );
+    List<DataElement> getDataElementsByAggregationLevel( int aggregationLevel );
+
+    List<DataElement> getDataElementsLikeName( String name );
+
+    List<DataElement> getDataElementsBetween( int first, int max );
+
+    List<DataElement> getDataElementsBetweenByName( String name, int first, int max );
 
     int getDataElementCount();
 
@@ -350,7 +350,7 @@
      * @param identifiers the id collection.
      * @return data elements with identifiers in the given collection.
      */
-    Collection<DataElementGroup> getDataElementGroups( Collection<Integer> identifiers );
+    List<DataElementGroup> getDataElementGroups( Collection<Integer> identifiers );
 
     /**
      * Returns the data element groups with the given uids.
@@ -382,7 +382,7 @@
      * @return a collection of all DataElementGroups, or an empty collection if
      *         no DataElementGroups exist.
      */
-    Collection<DataElementGroup> getAllDataElementGroups();
+    List<DataElementGroup> getAllDataElementGroups();
 
 
     /**
@@ -410,7 +410,7 @@
      * @return a collection of all DataElementGroups that contain the given
      *         DataElement.
      */
-    Collection<DataElementGroup> getGroupsContainingDataElement( DataElement dataElement );
+    List<DataElementGroup> getGroupsContainingDataElement( DataElement dataElement );
 
     /**
      * Returns data elements with identifier in the given id.
@@ -418,7 +418,7 @@
      * @param groupId is the id of data element group.
      * @return data elements with identifier in the given id.
      */
-    Collection<DataElement> getDataElementsByGroupId( int groupId );
+    Set<DataElement> getDataElementsByGroupId( int groupId );
 
     /**
      * Defines the given data elements as zero is significant. All other data
@@ -432,30 +432,30 @@
     /**
      * Returns all DataElement which zeroIsSignificant property is true or false
      *
-     * @param zeroIsSignificant is zeroIsSignificant property
+     * @param list is zeroIsSignificant property
      * @return a collection of all DataElement
      */
-    Collection<DataElement> getDataElementsByZeroIsSignificant( boolean zeroIsSignificant );
+    List<DataElement> getDataElementsByZeroIsSignificant( boolean zeroIsSignificant );
 
     /**
      * Returns all DataElement which zeroIsSignificant property is true or false
      *
      * @param zeroIsSignificant is zeroIsSignificant property
      * @param dataElementGroup  is group contain data elements
-     * @return a collection of all DataElement
+     * @return a set of data elements.
      */
-    Collection<DataElement> getDataElementsByZeroIsSignificantAndGroup( boolean zeroIsSignificant,
+    Set<DataElement> getDataElementsByZeroIsSignificantAndGroup( boolean zeroIsSignificant,
         DataElementGroup dataElementGroup );
 
-    Collection<DataElementGroup> getDataElementGroupsBetween( int first, int max );
+    List<DataElementGroup> getDataElementGroupsBetween( int first, int max );
 
-    Collection<DataElementGroup> getDataElementGroupsBetweenByName( String name, int first, int max );
+    List<DataElementGroup> getDataElementGroupsBetweenByName( String name, int first, int max );
 
     int getDataElementGroupCount();
 
     int getDataElementGroupCountByName( String name );
 
-    Collection<DataElement> getDataElements( DataSet dataSet, String key, Integer max );
+    List<DataElement> getDataElements( DataSet dataSet, String key, Integer max );
 
     // -------------------------------------------------------------------------
     // DataElementGroupSet
@@ -475,21 +475,21 @@
 
     DataElementGroupSet getDataElementGroupSetByName( String name );
 
-    Collection<DataElementGroupSet> getCompulsoryDataElementGroupSets();
-
-    Collection<DataElementGroupSet> getCompulsoryDataElementGroupSetsWithMembers();
-
-    Collection<DataElementGroupSet> getCompulsoryDataElementGroupSetsNotAssignedTo( DataElement dataElement );
-
-    Collection<DataElementGroupSet> getAllDataElementGroupSets();
-
-    Collection<DataElementGroupSet> getDataElementGroupSets( Collection<Integer> identifiers );
+    List<DataElementGroupSet> getCompulsoryDataElementGroupSets();
+
+    List<DataElementGroupSet> getCompulsoryDataElementGroupSetsWithMembers();
+
+    List<DataElementGroupSet> getCompulsoryDataElementGroupSetsNotAssignedTo( DataElement dataElement );
+
+    List<DataElementGroupSet> getAllDataElementGroupSets();
+
+    List<DataElementGroupSet> getDataElementGroupSets( Collection<Integer> identifiers );
 
     List<DataElementGroupSet> getDataElementGroupSetsByUid( Collection<String> uids );
 
-    Collection<DataElementGroupSet> getDataElementGroupSetsBetween( int first, int max );
+    List<DataElementGroupSet> getDataElementGroupSetsBetween( int first, int max );
 
-    Collection<DataElementGroupSet> getDataElementGroupSetsBetweenByName( String name, int first, int max );
+    List<DataElementGroupSet> getDataElementGroupSetsBetweenByName( String name, int first, int max );
 
     int getDataElementGroupSetCount();
 

=== modified file 'dhis-2/dhis-api/src/main/java/org/hisp/dhis/dataelement/DataElementStore.java'
--- dhis-2/dhis-api/src/main/java/org/hisp/dhis/dataelement/DataElementStore.java	2015-03-08 14:00:13 +0000
+++ dhis-2/dhis-api/src/main/java/org/hisp/dhis/dataelement/DataElementStore.java	2015-06-11 11:38:56 +0000
@@ -29,6 +29,7 @@
  */
 
 import java.util.Collection;
+import java.util.List;
 import java.util.Set;
 
 import org.hisp.dhis.common.GenericDimensionalObjectStore;
@@ -55,7 +56,7 @@
      * @param key the name of the DataElement to return.
      * @return List of DataElements with a given key, or all dataelements if no match.
      */
-    Collection<DataElement> searchDataElementsByName( String key );
+    List<DataElement> searchDataElementsByName( String key );
 
     /**
      * Returns all DataElements with types that are possible to aggregate. The
@@ -63,7 +64,7 @@
      * 
      * @return all DataElements with types that are possible to aggregate.
      */
-    Collection<DataElement> getAggregateableDataElements();
+    List<DataElement> getAggregateableDataElements();
 
     /**
      * Returns all DataElements with a given aggregation operator.
@@ -74,7 +75,7 @@
      *         operator, or an empty collection if no DataElements have the
      *         aggregation operator.
      */
-    Collection<DataElement> getDataElementsByAggregationOperator( String aggregationOperator );
+    List<DataElement> getDataElementsByAggregationOperator( String aggregationOperator );
 
     /**
      * Returns all DataElements with the given domain type.
@@ -82,7 +83,7 @@
      * @param domainType the domainType.
      * @return all DataElements with the given domainType.
      */
-    Collection<DataElement> getDataElementsByDomainType( DataElementDomain domainType );
+    List<DataElement> getDataElementsByDomainType( DataElementDomain domainType );
 
     /**
      * Returns all DataElements with the given domain type.
@@ -90,7 +91,7 @@
      * @param domainType the domainType.
      * @return all DataElements with the given domainType.
      */
-    Collection<DataElement> getDataElementsByDomainType( DataElementDomain domainType, int first, int max );
+    List<DataElement> getDataElementsByDomainType( DataElementDomain domainType, int first, int max );
 
     /**
      * Returns all DataElements with the given type.
@@ -99,7 +100,7 @@
      * @return all DataElements with the given type.
      */
 
-    Collection<DataElement> getDataElementsByType( String type );
+    List<DataElement> getDataElementsByType( String type );
 
     /**
      * Returns all DataElements with the given category combo.
@@ -107,7 +108,7 @@
      * @param categoryCombo the DataElementCategoryCombo.
      * @return all DataElements with the given category combo.
      */
-    Collection<DataElement> getDataElementByCategoryCombo( DataElementCategoryCombo categoryCombo );
+    List<DataElement> getDataElementByCategoryCombo( DataElementCategoryCombo categoryCombo );
 
     /**
      * Returns all DataElements which are associated with one or more
@@ -116,7 +117,7 @@
      * @return all DataElements which are associated with one or more
      *         DataElementGroupSets.
      */
-    Collection<DataElement> getDataElementsWithGroupSets();
+    List<DataElement> getDataElementsWithGroupSets();
 
     /**
      * Defines the given data elements as zero is significant. 
@@ -130,28 +131,28 @@
      * @param zeroIsSignificant is zeroIsSignificant property 
      * @return a collection of all DataElement
      */
-    Collection<DataElement> getDataElementsByZeroIsSignificant( boolean zeroIsSignificant );
+    List<DataElement> getDataElementsByZeroIsSignificant( boolean zeroIsSignificant );
     
     /**
      * Returns all DataElements which are not member of any DataElementGroups.
      * 
      * @return all DataElements which are not member of any DataElementGroups.
      */
-    Collection<DataElement> getDataElementsWithoutGroups();
+    List<DataElement> getDataElementsWithoutGroups();
     
     /**
      * Returns all DataElements which are not assigned to any DataSets.
      * 
      * @return all DataElements which are not assigned to any DataSets.
      */
-    Collection<DataElement> getDataElementsWithoutDataSets();
+    List<DataElement> getDataElementsWithoutDataSets();
     
     /**
      * Returns all DataElements which are assigned to at least one DataSet.
      * 
      * @return all DataElements which are assigned to at least one DataSet.
      */
-    Collection<DataElement> getDataElementsWithDataSets();
+    List<DataElement> getDataElementsWithDataSets();
     
     /**
      * Returns all DataElements which are assigned to any of the given DataSets.
@@ -159,7 +160,7 @@
      * @param dataSets the collection of DataSets.
      * @return all DataElements which are assigned to any of the given DataSets.
      */
-    Collection<DataElement> getDataElementsByDataSets( Collection<DataSet> dataSets );
+    List<DataElement> getDataElementsByDataSets( Collection<DataSet> dataSets );
     
     /**
      * Returns all DataElements which have the given aggregation level assigned.
@@ -167,7 +168,7 @@
      * @param aggregationLevel the aggregation level.
      * @return all DataElements which have the given aggregation level assigned.
      */
-    Collection<DataElement> getDataElementsByAggregationLevel( int aggregationLevel );
+    List<DataElement> getDataElementsByAggregationLevel( int aggregationLevel );
 
     /**
      * Returns a mapping of data element uid and associated category option combo
@@ -178,7 +179,7 @@
      */
     ListMap<String, String> getDataElementCategoryOptionComboMap( Set<String> dataElementUids );
     
-    Collection<DataElement> get( DataSet dataSet, String key, Integer max );
+    List<DataElement> get( DataSet dataSet, String key, Integer max );
 
     int getCountByDomainType( DataElementDomain domainType );
 }

=== modified file 'dhis-2/dhis-services/dhis-service-core/src/main/java/org/hisp/dhis/dataelement/DefaultDataElementService.java'
--- dhis-2/dhis-services/dhis-service-core/src/main/java/org/hisp/dhis/dataelement/DefaultDataElementService.java	2015-05-28 18:21:56 +0000
+++ dhis-2/dhis-services/dhis-service-core/src/main/java/org/hisp/dhis/dataelement/DefaultDataElementService.java	2015-06-11 11:38:56 +0000
@@ -131,15 +131,15 @@
     }
 
     @Override
-    public Collection<DataElement> getAllDataElements()
+    public List<DataElement> getAllDataElements()
     {
         return i18n( i18nService, dataElementStore.getAll() );
     }
 
     @Override
-    public Collection<DataElement> getDataElements( final Collection<Integer> identifiers )
+    public List<DataElement> getDataElements( final Collection<Integer> identifiers )
     {
-        Collection<DataElement> dataElements = getAllDataElements();
+        List<DataElement> dataElements = getAllDataElements();
 
         return identifiers == null ? dataElements : FilterUtils.filter( dataElements, new Filter<DataElement>()
         {
@@ -167,16 +167,16 @@
     }
 
     @Override
-    public Collection<DataElement> getDataElementsByZeroIsSignificant( boolean zeroIsSignificant )
+    public List<DataElement> getDataElementsByZeroIsSignificant( boolean zeroIsSignificant )
     {
         return dataElementStore.getDataElementsByZeroIsSignificant( zeroIsSignificant );
     }
 
     @Override
-    public Collection<DataElement> getDataElementsByZeroIsSignificantAndGroup( boolean zeroIsSignificant,
+    public Set<DataElement> getDataElementsByZeroIsSignificantAndGroup( boolean zeroIsSignificant,
         DataElementGroup dataElementGroup )
     {
-        Collection<DataElement> dataElements = new HashSet<>();
+        Set<DataElement> dataElements = new HashSet<>();
 
         for ( DataElement element : dataElementGroup.getMembers() )
         {
@@ -190,7 +190,7 @@
     }
 
     @Override
-    public Collection<DataElement> getAggregateableDataElements()
+    public List<DataElement> getAggregateableDataElements()
     {
         return i18n( i18nService, dataElementStore.getAggregateableDataElements() );
     }
@@ -209,7 +209,7 @@
     }
 
     @Override
-    public Collection<DataElement> searchDataElementsByName( String key )
+    public List<DataElement> searchDataElementsByName( String key )
     {
         return i18n( i18nService, dataElementStore.searchDataElementsByName( key ) );
     }
@@ -228,21 +228,21 @@
     }
 
     @Override
-    public Collection<DataElement> getDataElementsByAggregationOperator( String aggregationOperator )
+    public List<DataElement> getDataElementsByAggregationOperator( String aggregationOperator )
     {
         return i18n( i18nService, dataElementStore.getDataElementsByAggregationOperator( aggregationOperator ) );
     }
 
     @Override
-    public Collection<DataElement> getDataElementsByType( String type )
+    public List<DataElement> getDataElementsByType( String type )
     {
         return i18n( i18nService, dataElementStore.getDataElementsByType( type ) );
     }
 
     @Override
-    public Collection<DataElement> getDataElementsByPeriodType( final PeriodType periodType )
+    public List<DataElement> getDataElementsByPeriodType( final PeriodType periodType )
     {
-        Collection<DataElement> dataElements = getAllDataElements();
+        List<DataElement> dataElements = getAllDataElements();
 
         return FilterUtils.filter( dataElements, new Filter<DataElement>()
         {
@@ -255,19 +255,19 @@
     }
 
     @Override
-    public Collection<DataElement> getDataElementsByDomainType( DataElementDomain domainType )
+    public List<DataElement> getDataElementsByDomainType( DataElementDomain domainType )
     {
         return i18n( i18nService, dataElementStore.getDataElementsByDomainType( domainType ) );
     }
 
     @Override
-    public Collection<DataElement> getDataElementsByDomainType( DataElementDomain domainType, int first, int max )
+    public List<DataElement> getDataElementsByDomainType( DataElementDomain domainType, int first, int max )
     {
         return i18n( i18nService, dataElementStore.getDataElementsByDomainType( domainType, first, max ) );
     }
 
     @Override
-    public Collection<DataElement> getDataElementByCategoryCombo( DataElementCategoryCombo categoryCombo )
+    public List<DataElement> getDataElementByCategoryCombo( DataElementCategoryCombo categoryCombo )
     {
         return i18n( i18nService, dataElementStore.getDataElementByCategoryCombo( categoryCombo ) );
     }
@@ -314,31 +314,31 @@
     }
 
     @Override
-    public Collection<DataElement> getDataElementsWithGroupSets()
+    public List<DataElement> getDataElementsWithGroupSets()
     {
         return i18n( i18nService, dataElementStore.getDataElementsWithGroupSets() );
     }
 
     @Override
-    public Collection<DataElement> getDataElementsWithoutGroups()
+    public List<DataElement> getDataElementsWithoutGroups()
     {
         return i18n( i18nService, dataElementStore.getDataElementsWithoutGroups() );
     }
 
     @Override
-    public Collection<DataElement> getDataElementsWithoutDataSets()
+    public List<DataElement> getDataElementsWithoutDataSets()
     {
         return i18n( i18nService, dataElementStore.getDataElementsWithoutDataSets() );
     }
 
     @Override
-    public Collection<DataElement> getDataElementsWithDataSets()
+    public List<DataElement> getDataElementsWithDataSets()
     {
         return i18n( i18nService, dataElementStore.getDataElementsWithDataSets() );
     }
 
     @Override
-    public Collection<DataElement> getDataElementsLikeName( String name )
+    public List<DataElement> getDataElementsLikeName( String name )
     {
         return getObjectsByName( i18nService, dataElementStore, name );
     }
@@ -362,25 +362,25 @@
     }
 
     @Override
-    public Collection<DataElement> getDataElementsBetween( int first, int max )
+    public List<DataElement> getDataElementsBetween( int first, int max )
     {
         return getObjectsBetween( i18nService, dataElementStore, first, max );
     }
 
     @Override
-    public Collection<DataElement> getDataElementsBetweenByName( String name, int first, int max )
+    public List<DataElement> getDataElementsBetweenByName( String name, int first, int max )
     {
         return getObjectsBetweenByName( i18nService, dataElementStore, name, first, max );
     }
 
     @Override
-    public Collection<DataElement> getDataElementsByDataSets( Collection<DataSet> dataSets )
+    public List<DataElement> getDataElementsByDataSets( Collection<DataSet> dataSets )
     {
         return i18n( i18nService, dataElementStore.getDataElementsByDataSets( dataSets ) );
     }
 
     @Override
-    public Collection<DataElement> getDataElementsByAggregationLevel( int aggregationLevel )
+    public List<DataElement> getDataElementsByAggregationLevel( int aggregationLevel )
     {
         return i18n( i18nService, dataElementStore.getDataElementsByAggregationLevel( aggregationLevel ) );
     }
@@ -405,7 +405,7 @@
     }
 
     @Override
-    public Collection<DataElement> getDataElements( DataSet dataSet, String key, Integer max )
+    public List<DataElement> getDataElements( DataSet dataSet, String key, Integer max )
     {
         return i18n( i18nService, dataElementStore.get( dataSet, key, max ) );
     }
@@ -454,9 +454,9 @@
     }
 
     @Override
-    public Collection<DataElementGroup> getDataElementGroups( final Collection<Integer> identifiers )
+    public List<DataElementGroup> getDataElementGroups( final Collection<Integer> identifiers )
     {
-        Collection<DataElementGroup> groups = getAllDataElementGroups();
+        List<DataElementGroup> groups = getAllDataElementGroups();
 
         return identifiers == null ? groups : FilterUtils.filter( groups, new Filter<DataElementGroup>()
         {
@@ -481,7 +481,7 @@
     }
 
     @Override
-    public Collection<DataElementGroup> getAllDataElementGroups()
+    public List<DataElementGroup> getAllDataElementGroups()
     {
         return i18n( i18nService, dataElementGroupStore.getAll() );
     }
@@ -520,9 +520,9 @@
     }
 
     @Override
-    public Collection<DataElementGroup> getGroupsContainingDataElement( DataElement dataElement )
+    public List<DataElementGroup> getGroupsContainingDataElement( DataElement dataElement )
     {
-        Collection<DataElementGroup> groups = getAllDataElementGroups();
+        List<DataElementGroup> groups = getAllDataElementGroups();
 
         Iterator<DataElementGroup> iterator = groups.iterator();
 
@@ -538,7 +538,7 @@
     }
 
     @Override
-    public Collection<DataElement> getDataElementsByGroupId( int groupId )
+    public Set<DataElement> getDataElementsByGroupId( int groupId )
     {
         return i18n( i18nService, dataElementGroupStore.get( groupId ).getMembers() );
     }
@@ -556,13 +556,13 @@
     }
 
     @Override
-    public Collection<DataElementGroup> getDataElementGroupsBetween( int first, int max )
+    public List<DataElementGroup> getDataElementGroupsBetween( int first, int max )
     {
         return getObjectsBetween( i18nService, dataElementGroupStore, first, max );
     }
 
     @Override
-    public Collection<DataElementGroup> getDataElementGroupsBetweenByName( String name, int first, int max )
+    public List<DataElementGroup> getDataElementGroupsBetweenByName( String name, int first, int max )
     {
         return getObjectsBetweenByName( i18nService, dataElementGroupStore, name, first, max );
     }
@@ -629,9 +629,9 @@
     }
 
     @Override
-    public Collection<DataElementGroupSet> getCompulsoryDataElementGroupSets()
+    public List<DataElementGroupSet> getCompulsoryDataElementGroupSets()
     {
-        Collection<DataElementGroupSet> groupSets = new ArrayList<>();
+        List<DataElementGroupSet> groupSets = new ArrayList<>();
 
         for ( DataElementGroupSet groupSet : getAllDataElementGroupSets() )
         {
@@ -645,7 +645,7 @@
     }
 
     @Override
-    public Collection<DataElementGroupSet> getCompulsoryDataElementGroupSetsWithMembers()
+    public List<DataElementGroupSet> getCompulsoryDataElementGroupSetsWithMembers()
     {
         return FilterUtils.filter( getAllDataElementGroupSets(), new Filter<DataElementGroupSet>()
         {
@@ -658,9 +658,9 @@
     }
 
     @Override
-    public Collection<DataElementGroupSet> getCompulsoryDataElementGroupSetsNotAssignedTo( DataElement dataElement )
+    public List<DataElementGroupSet> getCompulsoryDataElementGroupSetsNotAssignedTo( DataElement dataElement )
     {
-        Collection<DataElementGroupSet> groupSets = new ArrayList<>();
+        List<DataElementGroupSet> groupSets = new ArrayList<>();
 
         for ( DataElementGroupSet groupSet : getCompulsoryDataElementGroupSets() )
         {
@@ -674,15 +674,15 @@
     }
 
     @Override
-    public Collection<DataElementGroupSet> getAllDataElementGroupSets()
+    public List<DataElementGroupSet> getAllDataElementGroupSets()
     {
         return i18n( i18nService, dataElementGroupSetStore.getAll() );
     }
 
     @Override
-    public Collection<DataElementGroupSet> getDataElementGroupSets( final Collection<Integer> identifiers )
+    public List<DataElementGroupSet> getDataElementGroupSets( final Collection<Integer> identifiers )
     {
-        Collection<DataElementGroupSet> groupSets = getAllDataElementGroupSets();
+        List<DataElementGroupSet> groupSets = getAllDataElementGroupSets();
 
         return identifiers == null ? groupSets : FilterUtils.filter( groupSets, new Filter<DataElementGroupSet>()
         {
@@ -713,13 +713,13 @@
     }
 
     @Override
-    public Collection<DataElementGroupSet> getDataElementGroupSetsBetween( int first, int max )
+    public List<DataElementGroupSet> getDataElementGroupSetsBetween( int first, int max )
     {
         return getObjectsBetween( i18nService, dataElementGroupSetStore, first, max );
     }
 
     @Override
-    public Collection<DataElementGroupSet> getDataElementGroupSetsBetweenByName( String name, int first, int max )
+    public List<DataElementGroupSet> getDataElementGroupSetsBetweenByName( String name, int first, int max )
     {
         return getObjectsBetweenByName( i18nService, dataElementGroupSetStore, name, first, max );
     }

=== modified file 'dhis-2/dhis-services/dhis-service-core/src/main/java/org/hisp/dhis/dataelement/hibernate/HibernateDataElementStore.java'
--- dhis-2/dhis-services/dhis-service-core/src/main/java/org/hisp/dhis/dataelement/hibernate/HibernateDataElementStore.java	2015-05-28 14:33:21 +0000
+++ dhis-2/dhis-services/dhis-service-core/src/main/java/org/hisp/dhis/dataelement/hibernate/HibernateDataElementStore.java	2015-06-11 11:38:56 +0000
@@ -34,6 +34,7 @@
 import java.sql.SQLException;
 import java.util.Collection;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Set;
 
 import org.apache.commons.logging.Log;
@@ -68,14 +69,14 @@
 
     @Override
     @SuppressWarnings("unchecked")
-    public Collection<DataElement> searchDataElementsByName( String key )
+    public List<DataElement> searchDataElementsByName( String key )
     {
         return getCriteria( Restrictions.ilike( "name", "%" + key + "%" ) ).list();
     }
 
     @Override
     @SuppressWarnings("unchecked")
-    public Collection<DataElement> getAggregateableDataElements()
+    public List<DataElement> getAggregateableDataElements()
     {
         Set<String> types = new HashSet<>();
 
@@ -87,28 +88,28 @@
 
     @Override
     @SuppressWarnings("unchecked")
-    public Collection<DataElement> getDataElementsByAggregationOperator( String aggregationOperator )
+    public List<DataElement> getDataElementsByAggregationOperator( String aggregationOperator )
     {
         return getCriteria( Restrictions.eq( "aggregationOperator", aggregationOperator ) ).list();
     }
 
     @Override
     @SuppressWarnings("unchecked")
-    public Collection<DataElement> getDataElementsByType( String type )
+    public List<DataElement> getDataElementsByType( String type )
     {
         return getCriteria( Restrictions.eq( "type", type ) ).list();
     }
 
     @Override
     @SuppressWarnings( "unchecked" )
-    public Collection<DataElement> getDataElementsByDomainType( DataElementDomain domainType )
+    public List<DataElement> getDataElementsByDomainType( DataElementDomain domainType )
     {
         return getCriteria( Restrictions.eq( "domainType", domainType ) ).list();
     }
 
     @Override
     @SuppressWarnings("unchecked")
-    public Collection<DataElement> getDataElementsByDomainType( DataElementDomain domainType, int first, int max )
+    public List<DataElement> getDataElementsByDomainType( DataElementDomain domainType, int first, int max )
     {
         Criteria criteria = getCriteria();
         criteria.add( Restrictions.eq( "domainType", domainType ) );
@@ -122,14 +123,14 @@
 
     @Override
     @SuppressWarnings("unchecked")
-    public Collection<DataElement> getDataElementByCategoryCombo( DataElementCategoryCombo categoryCombo )
+    public List<DataElement> getDataElementByCategoryCombo( DataElementCategoryCombo categoryCombo )
     {
         return getCriteria( Restrictions.eq( "categoryCombo", categoryCombo ) ).list();
     }
 
     @Override
     @SuppressWarnings("unchecked")
-    public Collection<DataElement> getDataElementsWithGroupSets()
+    public List<DataElement> getDataElementsWithGroupSets()
     {
         String hql = "from DataElement d where d.groupSets.size > 0";
 
@@ -160,7 +161,7 @@
 
     @Override
     @SuppressWarnings("unchecked")
-    public Collection<DataElement> getDataElementsByZeroIsSignificant( boolean zeroIsSignificant )
+    public List<DataElement> getDataElementsByZeroIsSignificant( boolean zeroIsSignificant )
     {
         Criteria criteria = getCriteria();
         criteria.add( Restrictions.eq( "zeroIsSignificant", zeroIsSignificant ) );
@@ -171,7 +172,7 @@
 
     @Override
     @SuppressWarnings("unchecked")
-    public Collection<DataElement> getDataElementsWithoutGroups()
+    public List<DataElement> getDataElementsWithoutGroups()
     {
         String hql = "from DataElement d where d.groups.size = 0";
 
@@ -180,7 +181,7 @@
 
     @Override
     @SuppressWarnings("unchecked")
-    public Collection<DataElement> getDataElementsWithoutDataSets()
+    public List<DataElement> getDataElementsWithoutDataSets()
     {
         String hql = "from DataElement d where d.dataSets.size = 0 and d.domainType =:domainType";
 
@@ -189,7 +190,7 @@
 
     @Override
     @SuppressWarnings("unchecked")
-    public Collection<DataElement> getDataElementsWithDataSets()
+    public List<DataElement> getDataElementsWithDataSets()
     {
         String hql = "from DataElement d where d.dataSets.size > 0";
 
@@ -198,7 +199,7 @@
 
     @Override
     @SuppressWarnings("unchecked")
-    public Collection<DataElement> getDataElementsByDataSets( Collection<DataSet> dataSets )
+    public List<DataElement> getDataElementsByDataSets( Collection<DataSet> dataSets )
     {
         String hql = "select distinct de from DataElement de join de.dataSets ds where ds.id in (:ids)";
 
@@ -207,7 +208,7 @@
 
     @Override
     @SuppressWarnings("unchecked")
-    public Collection<DataElement> getDataElementsByAggregationLevel( int aggregationLevel )
+    public List<DataElement> getDataElementsByAggregationLevel( int aggregationLevel )
     {
         String hql = "from DataElement de join de.aggregationLevels al where al = :aggregationLevel";
 
@@ -250,7 +251,7 @@
 
     @Override
     @SuppressWarnings("unchecked")
-    public Collection<DataElement> get( DataSet dataSet, String key, Integer max )
+    public List<DataElement> get( DataSet dataSet, String key, Integer max )
     {
         String hql = "select dataElement from DataSet dataSet inner join dataSet.dataElements as dataElement where dataSet.id = :dataSetId ";
 

=== modified file 'dhis-2/dhis-services/dhis-service-core/src/main/java/org/hisp/dhis/i18n/I18nUtils.java'
--- dhis-2/dhis-services/dhis-service-core/src/main/java/org/hisp/dhis/i18n/I18nUtils.java	2015-05-28 03:33:28 +0000
+++ dhis-2/dhis-services/dhis-service-core/src/main/java/org/hisp/dhis/i18n/I18nUtils.java	2015-06-11 11:38:56 +0000
@@ -28,7 +28,6 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-import java.util.Collection;
 import java.util.List;
 import java.util.Locale;
 
@@ -73,7 +72,7 @@
             Paging.getCountByName( i18n( i18nService, store.getAll() ), name );
     }
     
-    public static <T extends IdentifiableObject> Collection<T> getObjectsBetween( 
+    public static <T extends IdentifiableObject> List<T> getObjectsBetween( 
         I18nService i18nService, GenericIdentifiableObjectStore<T> store, int first, int max )
     {
         return i18nService.currentLocaleIsBase() ?
@@ -81,7 +80,7 @@
             Paging.getObjectsBetween( i18n( i18nService, store.getAll() ), first, max );
     }
     
-    public static <T extends IdentifiableObject> Collection<T> getObjectsBetweenByName(
+    public static <T extends IdentifiableObject> List<T> getObjectsBetweenByName(
         I18nService i18nService, GenericIdentifiableObjectStore<T> store, String name, int first, int max )
     {
         return i18nService.currentLocaleIsBase() ?
@@ -89,7 +88,7 @@
             Paging.getObjectsBetweenByName( i18n( i18nService, store.getAll() ), name, first, max );
     }
     
-    public static <T extends IdentifiableObject> Collection<T> getObjectsByName(
+    public static <T extends IdentifiableObject> List<T> getObjectsByName(
         I18nService i18nService, GenericIdentifiableObjectStore<T> store, String name )
     {
         return i18nService.currentLocaleIsBase() ?

=== modified file 'dhis-2/dhis-support/dhis-support-commons/src/main/java/org/hisp/dhis/util/FilterUtils.java'
--- dhis-2/dhis-support/dhis-support-commons/src/main/java/org/hisp/dhis/util/FilterUtils.java	2015-05-28 18:21:56 +0000
+++ dhis-2/dhis-support/dhis-support-commons/src/main/java/org/hisp/dhis/util/FilterUtils.java	2015-06-11 11:38:56 +0000
@@ -43,17 +43,17 @@
      *
      * @param collection the Collection.
      * @param filter the Filter.
-     * @param <T> the type of the Collection members.
+     * @param <V> the type of the Collection members.
      * @return the filtered Collection.
      */
-    public static <T> Collection<T> filter( Collection<T> collection, Filter<T> filter )
+    public static <T extends Collection<V>, V> T filter( T collection, Filter<V> filter )
     {
         if ( collection == null || filter == null )
         {
             return collection;
         }
         
-        final Iterator<T> iterator = collection.iterator();
+        final Iterator<V> iterator = collection.iterator();
         
         while ( iterator.hasNext() )
         {

=== modified file 'dhis-2/dhis-support/dhis-support-system/src/main/java/org/hisp/dhis/system/paging/Paging.java'
--- dhis-2/dhis-support/dhis-support-system/src/main/java/org/hisp/dhis/system/paging/Paging.java	2015-01-17 07:41:26 +0000
+++ dhis-2/dhis-support/dhis-support-system/src/main/java/org/hisp/dhis/system/paging/Paging.java	2015-06-11 11:38:56 +0000
@@ -224,7 +224,7 @@
         return list.subList( first, last );
     }
     
-    public static <T extends IdentifiableObject> Collection<T> getObjectsByName( Collection<T> objects, String name )
+    public static <T extends IdentifiableObject> List<T> getObjectsByName( Collection<T> objects, String name )
     {
         final List<T> list = new ArrayList<>();