[DS-3003] Ensure all service & DAO implementations have a protected constructor

dspace-api/src/main/java/org/dspace/content/SiteServiceImpl.java

@@ -40,6 +40,11 @@ public class SiteServiceImpl extends DSpaceObjectServiceImpl<Site> implements Si
     @Autowired(required = true)
     protected SiteDAO siteDAO;
 
+    protected SiteServiceImpl()
+    {
+        super();
+    }
+
     @Override
     public Site createSite(Context context) throws SQLException {
         Site site = findSite(context);

dspace-api/src/main/java/org/dspace/eperson/EPersonServiceImpl.java

@@ -54,6 +54,11 @@ public class EPersonServiceImpl extends DSpaceObjectServiceImpl<EPerson> impleme
     @Autowired(required = true)
     protected SubscribeService subscribeService;
 
+    protected EPersonServiceImpl()
+    {
+        super();
+    }
+
     @Override
     public EPerson find(Context context, UUID id) throws SQLException {
         return ePersonDAO.findByID(context, EPerson.class, id);

dspace-api/src/main/java/org/dspace/eperson/GroupServiceImpl.java

@@ -65,6 +65,10 @@ public class GroupServiceImpl extends DSpaceObjectServiceImpl<Group> implements
     @Autowired(required = true)
     protected AuthorizeService authorizeService;
 
+    protected GroupServiceImpl()
+    {
+        super();
+    }
 
     @Override
     public Group create(Context context) throws SQLException, AuthorizeException {