SI-731 correction with plz list mapping. Asserted by unit tests.
diff --git a/gfsBackendService/src/main/java/org/eclipse/openk/gridfailureinformation/mapper/DistributionGroupMemberMapper.java b/gfsBackendService/src/main/java/org/eclipse/openk/gridfailureinformation/mapper/DistributionGroupMemberMapper.java
index c773c97..9b772da 100644
--- a/gfsBackendService/src/main/java/org/eclipse/openk/gridfailureinformation/mapper/DistributionGroupMemberMapper.java
+++ b/gfsBackendService/src/main/java/org/eclipse/openk/gridfailureinformation/mapper/DistributionGroupMemberMapper.java
@@ -45,6 +45,7 @@
                     .split(","));
 
         targetDto.setPostcodeList(result.stream()
+                 .filter( x -> !x.isEmpty() )
                  .sorted( String::compareTo )
                         .collect(Collectors.toList())
         );
@@ -61,6 +62,7 @@
     default void mapPostcodesFromList(DistributionGroupMemberDto srcDto, @MappingTarget TblDistributionGroupMember targetTbl) {
         StringBuilder sb = new StringBuilder();
         Optional.ofNullable(srcDto.getPostcodeList()).orElse( new ArrayList<>()).stream()
+                .filter( x -> x!=null && !x.isEmpty() )
                 .sorted(String::compareTo)
                 .forEach(x -> sb.append("," + x));
         targetTbl.setPostcodes(
diff --git a/gfsBackendService/src/test/java/org/eclipse/openk/gridfailureinformation/service/DistributionGroupServiceMemberTest.java b/gfsBackendService/src/test/java/org/eclipse/openk/gridfailureinformation/service/DistributionGroupServiceMemberTest.java
index 21cff40..de3606b 100644
--- a/gfsBackendService/src/test/java/org/eclipse/openk/gridfailureinformation/service/DistributionGroupServiceMemberTest.java
+++ b/gfsBackendService/src/test/java/org/eclipse/openk/gridfailureinformation/service/DistributionGroupServiceMemberTest.java
@@ -18,6 +18,7 @@
 import org.eclipse.openk.gridfailureinformation.config.TestConfiguration;
 import org.eclipse.openk.gridfailureinformation.exceptions.NotFoundException;
 import org.eclipse.openk.gridfailureinformation.exceptions.OperationDeniedException;
+import org.eclipse.openk.gridfailureinformation.mapper.DistributionGroupMemberMapper;
 import org.eclipse.openk.gridfailureinformation.model.TblDistributionGroup;
 import org.eclipse.openk.gridfailureinformation.model.TblDistributionGroupMember;
 import org.eclipse.openk.gridfailureinformation.repository.DistributionGroupMemberRepository;
@@ -36,6 +37,7 @@
 import org.springframework.security.test.context.support.WithMockUser;
 import org.springframework.test.context.ContextConfiguration;
 
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Optional;
 import java.util.UUID;
@@ -54,11 +56,14 @@
 @DataJpaTest
 @ContextConfiguration(classes = {TestConfiguration.class})
 
-public class DistributionGroupServiceMemberTest {
+class DistributionGroupServiceMemberTest {
     @Qualifier("myDistributionGroupMemberService")
     @Autowired
     private DistributionGroupMemberService distributionGroupMemberService;
 
+    @Autowired
+    private DistributionGroupMemberMapper distributionGroupMemberMapper;
+
     @MockBean
     private DistributionGroupMemberRepository distributionGroupMemberRepository;
 
@@ -69,7 +74,7 @@
     private ContactApi contactApi;
 
     @Test
-    public void shouldGetAllDistributionGroupMembers() {
+    void shouldGetAllDistributionGroupMembers() {
         List<TblDistributionGroupMember> groupMembers = MockDataHelper.mockDistributionGroupMemberList();
         when(distributionGroupMemberRepository.findAll()).thenReturn(groupMembers);
         List<DistributionGroupMemberDto> groupMemberDtoList = distributionGroupMemberService.getDistributionGroupMembers();
@@ -81,7 +86,7 @@
 
     @Test
     @WithMockUser(username = "admin", authorities = { "ADMIN", "USER" })
-    public void shouldGetAllMembersOfASingleDistributionGroup() {
+    void shouldGetAllMembersOfASingleDistributionGroup() {
         List<TblDistributionGroupMember> groupMembers = MockDataHelper.mockDistributionGroupMemberList();
         when(distributionGroupMemberRepository.findByTblDistributionGroupUuid(any(UUID.class))).thenReturn(groupMembers);
         List<DistributionGroupMemberDto> groupMemberDtoList = distributionGroupMemberService.getMembersByGroupId(groupMembers.get(1).getTblDistributionGroup().getUuid());
@@ -92,8 +97,36 @@
     }
 
     @Test
+    void shouldMapEmptyPlzListCorrectly() {
+        TblDistributionGroupMember tbl1 = MockDataHelper.mockTblDistributionGroupMember();
+        tbl1.setPostcodes(null);
+        assertTrue(distributionGroupMemberMapper.toDistributionGroupMemberDto(tbl1).getPostcodeList().isEmpty());
+
+        TblDistributionGroupMember tbl2 = MockDataHelper.mockTblDistributionGroupMember();
+        tbl2.setPostcodes("");
+        assertTrue(distributionGroupMemberMapper.toDistributionGroupMemberDto(tbl2).getPostcodeList().isEmpty());
+
+        TblDistributionGroupMember tbl3 = MockDataHelper.mockTblDistributionGroupMember();
+        tbl3.setPostcodes("5,3,1");
+        DistributionGroupMemberDto dto3 = distributionGroupMemberMapper.toDistributionGroupMemberDto(tbl3);
+        assertEquals("1", dto3.getPostcodeList().get(0));
+        assertEquals("3", dto3.getPostcodeList().get(1));
+        assertEquals("5", dto3.getPostcodeList().get(2));
+
+        List<String> testList = new LinkedList<>();
+        testList.add(null);
+        testList.add("");
+        testList.add("32");
+        testList.add("23");
+
+        dto3.setPostcodeList(testList);
+        TblDistributionGroupMember tblResult = distributionGroupMemberMapper.toTblDistributionGroupMember(dto3);
+        assertEquals( "23,32", tblResult.getPostcodes());
+    }
+
+    @Test
     @WithMockUser(username = "admin", authorities = { "ADMIN", "USER" })
-    public void shouldFindASingleDistributionGroupMember() {
+    void shouldFindASingleDistributionGroupMember() {
         TblDistributionGroupMember groupMember = MockDataHelper.mockTblDistributionGroupMember();
         when(distributionGroupMemberRepository.findByUuid(any(UUID.class))).thenReturn(Optional.of(groupMember));
         DistributionGroupMemberDto dto = distributionGroupMemberService.getMemberByUuid(groupMember.getTblDistributionGroup().getUuid(), UUID.randomUUID());
@@ -106,7 +139,8 @@
     @Test
     void shouldHandleLoadFileWithNotFoundException() {
         when(distributionGroupRepository.findByUuid(any(UUID.class))).thenReturn(Optional.empty());
-        assertThrows( NotFoundException.class, () -> distributionGroupMemberService.handleLoadFile(UUID.randomUUID()));
+        UUID uuid = UUID.randomUUID();
+        assertThrows( NotFoundException.class, () -> distributionGroupMemberService.handleLoadFile(uuid));
     }
 
     @Test
@@ -126,15 +160,17 @@
     }
 
     @Test
-    public void shouldThrowExceptionWhenFailureNotFound() {
+    void shouldThrowExceptionWhenFailureNotFound() {
         TblDistributionGroupMember groupMember = MockDataHelper.mockTblDistributionGroupMember();
         when(distributionGroupMemberRepository.findByUuid(any(UUID.class))).thenReturn(Optional.empty());
+        UUID uuid = UUID.randomUUID();
+        UUID dgMemberUuid = groupMember.getTblDistributionGroup().getUuid();
         assertThrows(NotFoundException.class,
-                () -> distributionGroupMemberService.getMemberByUuid(groupMember.getTblDistributionGroup().getUuid(), UUID.randomUUID()));
+                () -> distributionGroupMemberService.getMemberByUuid(dgMemberUuid, uuid));
     }
 
     @Test
-    public void shouldInsertADistributionGroupMember() {
+    void shouldInsertADistributionGroupMember() {
         DistributionGroupMemberDto memberDto = MockDataHelper.mockDistributionGroupMemberDto();
         TblDistributionGroupMember tblDistributionGroupMember = MockDataHelper.mockTblDistributionGroupMember();
 
@@ -152,7 +188,7 @@
     }
 
     @Test
-    public void shouldNotInsertMember_Exception_Member_Exists() {
+    void shouldNotInsertMember_Exception_Member_Exists() {
         DistributionGroupMemberDto memberDto = MockDataHelper.mockDistributionGroupMemberDto();
         TblDistributionGroupMember tblDistributionGroupMember = MockDataHelper.mockTblDistributionGroupMember();
 
@@ -161,12 +197,12 @@
         when(distributionGroupRepository.findByUuid(any(UUID.class))).thenReturn(Optional.of(tblDistributionGroup));
         when(distributionGroupMemberRepository.countByDistributionGroupIdAndContactId(anyLong(),any(UUID.class))).thenReturn(4L);
         when(distributionGroupMemberRepository.save(any(TblDistributionGroupMember.class))).thenReturn(tblDistributionGroupMember);
-
-        assertThrows(OperationDeniedException.class, () -> distributionGroupMemberService.insertDistributionGroupMember(UUID.randomUUID(), memberDto));
+        UUID uuid = UUID.randomUUID();
+        assertThrows(OperationDeniedException.class, () -> distributionGroupMemberService.insertDistributionGroupMember(uuid, memberDto));
     }
 
     @Test
-    public void shouldDeleteDistributionGroupMember() {
+    void shouldDeleteDistributionGroupMember() {
         TblDistributionGroupMember tblDistributionGroupMember = MockDataHelper.mockTblDistributionGroupMember();
         TblDistributionGroup tblDistributionGroup = MockDataHelper.mockTblDistributionGroup();
 
@@ -181,7 +217,7 @@
 
 
     @Test
-    public void shouldUpdateDistributionGroupMember() {
+    void shouldUpdateDistributionGroupMember() {
         DistributionGroupMemberDto memberDto = MockDataHelper.mockDistributionGroupMemberDto();
         TblDistributionGroupMember tblDistributionGroupMember = MockDataHelper.mockTblDistributionGroupMember();
         TblDistributionGroup tblDistributionGroup = MockDataHelper.mockTblDistributionGroup();
@@ -195,7 +231,7 @@
     }
 
     @Test
-    public void shouldNotUpdateMember_Exception_GroupNotFound() {
+    void shouldNotUpdateMember_Exception_GroupNotFound() {
         DistributionGroupMemberDto memberDto = MockDataHelper.mockDistributionGroupMemberDto();
         TblDistributionGroupMember tblDistributionGroupMember = MockDataHelper.mockTblDistributionGroupMember();
         TblDistributionGroup tblDistributionGroup = MockDataHelper.mockTblDistributionGroup();
@@ -209,7 +245,8 @@
                     Object[] args = invocation.getArguments();
                     return (TblDistributionGroupMember) args[0];
                 });
-        assertThrows(NotFoundException.class, () -> distributionGroupMemberService.updateGroupMember(UUID.randomUUID(), memberDto));
+        UUID uuid = UUID.randomUUID();
+        assertThrows(NotFoundException.class, () -> distributionGroupMemberService.updateGroupMember(uuid, memberDto));
 
     }