Bug fixed related to waste id was fixed

src/main/java/ntnu/idatt2016/v233/SmartMat/repository/group/WasteRepository.java

@@ -2,6 +2,7 @@ package ntnu.idatt2016.v233.SmartMat.repository.group;
 
 import java.util.List;
 import ntnu.idatt2016.v233.SmartMat.entity.Waste;
+import ntnu.idatt2016.v233.SmartMat.entity.group.Group;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.query.Param;
@@ -9,7 +10,7 @@ import org.springframework.data.repository.query.Param;
 import java.util.Optional;
 
 public interface WasteRepository extends JpaRepository<Waste, Long> {
-    Optional<List<Waste>> findByGroupId(long groupId);
+    Optional<List<Waste>> findByGroupId( Group groupId);
 
 
     /**

src/main/java/ntnu/idatt2016/v233/SmartMat/service/group/WasteService.java

@@ -47,7 +47,9 @@ public class WasteService {
      * @return an optional containing the waste if it exists
      */
     public Optional<List<Waste>> getWasteByGroupId(long groupId) {
-        return wasteRepository.findByGroupId(groupId);
+        Optional<Group> group = groupRepository.findByGroupId(groupId);
+        if(group.isPresent()) return wasteRepository.findByGroupId(group.get());
+        return Optional.empty();
     }
 
     /**