=== modified file 'dhis-2/dhis-services/dhis-service-core/src/main/java/org/hisp/dhis/preheat/DefaultPreheatService.java'
--- dhis-2/dhis-services/dhis-service-core/src/main/java/org/hisp/dhis/preheat/DefaultPreheatService.java	2016-03-13 11:05:30 +0000
+++ dhis-2/dhis-services/dhis-service-core/src/main/java/org/hisp/dhis/preheat/DefaultPreheatService.java	2016-03-14 01:56:52 +0000
@@ -61,6 +61,7 @@
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -683,17 +684,25 @@
             return objectErrorReports;
         }
 
-        for ( int i = 0; i < objects.size(); i++ )
+        Iterator<IdentifiableObject> iterator = objects.iterator();
+        int idx = 0;
+
+        while ( iterator.hasNext() )
         {
-            IdentifiableObject object = objects.get( i );
+            IdentifiableObject object = iterator.next();
+
             List<ErrorReport> errorReports = checkUniqueness( object, preheat, identifier );
 
-            if ( errorReports.isEmpty() ) continue;
-
-            ObjectErrorReport objectErrorReport = new ObjectErrorReport( object.getClass(), i );
-            objectErrorReport.addErrorReports( errorReports );
-            objectErrorReports.add( objectErrorReport );
-
+            if ( !errorReports.isEmpty() )
+            {
+                ObjectErrorReport objectErrorReport = new ObjectErrorReport( object.getClass(), idx );
+                objectErrorReport.addErrorReports( errorReports );
+                objectErrorReports.add( objectErrorReport );
+
+                iterator.remove();
+            }
+
+            idx++;
         }
 
         return objectErrorReports;
@@ -706,10 +715,13 @@
 
         if ( object == null || Preheat.isDefault( object ) ) return errorReports;
 
+        if ( !preheat.getUniquenessMap().containsKey( object.getClass() ) )
+        {
+            preheat.getUniquenessMap().put( object.getClass(), new HashMap<>() );
+        }
+
         Map<String, Map<Object, String>> uniquenessMap = preheat.getUniquenessMap().get( object.getClass() );
 
-        if ( uniquenessMap == null ) return errorReports;
-
         Schema schema = schemaService.getDynamicSchema( object.getClass() );
         List<Property> uniqueProperties = schema.getProperties().stream()
             .filter( p -> p.isPersisted() && p.isOwner() && p.isUnique() )
@@ -733,6 +745,15 @@
                         }
                     }
                 }
+                else
+                {
+                    if ( !uniquenessMap.containsKey( property.getName() ) )
+                    {
+                        uniquenessMap.put( property.getName(), new HashMap<>() );
+                    }
+
+                    uniquenessMap.get( property.getName() ).put( value, object.getUid() );
+                }
             }
         } );
 

=== modified file 'dhis-2/dhis-services/dhis-service-dxf2/src/main/java/org/hisp/dhis/dxf2/metadata2/objectbundle/DefaultObjectBundleService.java'
--- dhis-2/dhis-services/dhis-service-dxf2/src/main/java/org/hisp/dhis/dxf2/metadata2/objectbundle/DefaultObjectBundleService.java	2016-03-13 11:05:30 +0000
+++ dhis-2/dhis-services/dhis-service-dxf2/src/main/java/org/hisp/dhis/dxf2/metadata2/objectbundle/DefaultObjectBundleService.java	2016-03-14 01:56:52 +0000
@@ -117,11 +117,14 @@
         {
             if ( bundle.getImportMode().isCreateAndUpdate() )
             {
-                objectBundleValidation.addObjectErrorReports( validateBySchemas( klass, bundle.getObjectMap().get( klass ), bundle ) );
+                objectBundleValidation.addObjectErrorReports( validateBySchemas( klass, bundle.getObjects( klass, false ), bundle ) );
+                objectBundleValidation.addObjectErrorReports( validateBySchemas( klass, bundle.getObjects( klass, true ), bundle ) );
+
+                objectBundleValidation.addObjectErrorReports( preheatService.checkUniqueness( bundle.getObjects( klass, false ), bundle.getPreheat(),
+                    bundle.getPreheatIdentifier() ) );
+
                 objectBundleValidation.addObjectErrorReports( preheatService.checkReferences( bundle.getObjectMap().get( klass ),
                     bundle.getPreheat(), bundle.getPreheatIdentifier() ) );
-                objectBundleValidation.addObjectErrorReports( preheatService.checkUniqueness( bundle.getObjectMap().get( klass ), bundle.getPreheat(),
-                    bundle.getPreheatIdentifier() ) );
             }
 
             if ( bundle.getImportMode().isCreate() )

=== modified file 'dhis-2/dhis-services/dhis-service-dxf2/src/test/java/org/hisp/dhis/dxf2/metadata2/objectbundle/ObjectBundleServiceTest.java'
--- dhis-2/dhis-services/dhis-service-dxf2/src/test/java/org/hisp/dhis/dxf2/metadata2/objectbundle/ObjectBundleServiceTest.java	2016-03-13 10:19:38 +0000
+++ dhis-2/dhis-services/dhis-service-dxf2/src/test/java/org/hisp/dhis/dxf2/metadata2/objectbundle/ObjectBundleServiceTest.java	2016-03-14 01:56:52 +0000
@@ -1389,6 +1389,30 @@
         assertEquals( 1, validate.getErrorReportsByCode( UserAuthorityGroup.class, ErrorCode.E5003 ).size() );
     }
 
+    @Test
+    public void testCreateMetadataWithDuplicateDataElementCode() throws IOException
+    {
+        createUserAndInjectSecurityContext( true );
+
+        Map<Class<? extends IdentifiableObject>, List<IdentifiableObject>> metadata = renderService.fromMetadata(
+            new ClassPathResource( "dxf2/de_duplicate_code.json" ).getInputStream(), RenderFormat.JSON );
+
+        ObjectBundleParams params = new ObjectBundleParams();
+        params.setObjectBundleMode( ObjectBundleMode.COMMIT );
+        params.setImportMode( ImportStrategy.CREATE_AND_UPDATE );
+        params.setObjects( metadata );
+
+        ObjectBundle bundle = objectBundleService.create( params );
+        objectBundleService.validate( bundle );
+        objectBundleService.commit( bundle );
+
+        assertEquals( 1, manager.getAll( DataElement.class ).size() );
+
+        DataElement dataElement = manager.getByCode( DataElement.class, "DataElementCodeA" );
+        assertEquals( "SG4HuKlNEFH", dataElement.getUid() );
+        assertEquals( "DataElementA", dataElement.getName() );
+    }
+
     private void defaultSetup()
     {
         DataElement de1 = createDataElement( 'A' );

=== added file 'dhis-2/dhis-services/dhis-service-dxf2/src/test/resources/dxf2/de_duplicate_code.json'
--- dhis-2/dhis-services/dhis-service-dxf2/src/test/resources/dxf2/de_duplicate_code.json	1970-01-01 00:00:00 +0000
+++ dhis-2/dhis-services/dhis-service-dxf2/src/test/resources/dxf2/de_duplicate_code.json	2016-03-14 01:56:52 +0000
@@ -0,0 +1,48 @@
+{
+  "dataElements": [
+    {
+      "attributeValues": [ ],
+      "userGroupAccesses": [ ],
+      "valueType": "TEXT",
+      "aggregationType": "SUM",
+      "created": "2016-02-17T06:15:06.079+0000",
+      "shortName": "DataElementShortA",
+      "categoryCombo": {
+        "id": "zU1OZFVxnw7"
+      },
+      "aggregationLevels": [ ],
+      "id": "SG4HuKlNEFH",
+      "domainType": "AGGREGATE",
+      "lastUpdated": "2016-02-17T06:15:59.378+0000",
+      "user": {
+        "id": "ueKaFVdR8Fz"
+      },
+      "zeroIsSignificant": false,
+      "publicAccess": "rw------",
+      "code": "DataElementCodeA",
+      "name": "DataElementA"
+    },
+    {
+      "code": "DataElementCodeA",
+      "publicAccess": "rw------",
+      "name": "DataElementB",
+      "attributeValues": [ ],
+      "userGroupAccesses": [ ],
+      "valueType": "TEXT",
+      "aggregationType": "SUM",
+      "shortName": "DataElementShortB",
+      "created": "2016-02-17T06:15:49.487+0000",
+      "categoryCombo": {
+        "id": "zU1OZFVxnw7"
+      },
+      "id": "CCwk5Yx440o",
+      "aggregationLevels": [ ],
+      "domainType": "AGGREGATE",
+      "user": {
+        "id": "ueKaFVdR8Fz"
+      },
+      "lastUpdated": "2016-02-17T06:16:08.180+0000",
+      "zeroIsSignificant": false
+    }
+  ]
+}
\ No newline at end of file