Better exceptio handling

ccm-core/src/main/java/org/libreccm/core/CcmObjectIdResolver.java

@@ -23,8 +23,11 @@ import com.fasterxml.jackson.annotation.ObjectIdResolver;
 import org.libreccm.cdi.utils.CdiUtil;
 
 import javax.enterprise.context.RequestScoped;
+
 import java.io.Serializable;
 
+import javax.persistence.NonUniqueResultException;
+
 /**
  * Used to resolve {@link CcmObject}s based on their UUIDs when importing and
  * exporting them.
@@ -49,6 +52,7 @@ public class CcmObjectIdResolver implements Serializable, ObjectIdResolver {
 
     @Override
     public Object resolveId(final ObjectIdGenerator.IdKey id) {
+        try {
         return CdiUtil
             .createCdiUtil()
             .findBean(CcmObjectRepository.class)
@@ -61,6 +65,15 @@ public class CcmObjectIdResolver implements Serializable, ObjectIdResolver {
                     )
                 )
             );
+        } catch(NonUniqueResultException ex) {
+            throw new UnexpectedErrorException(
+                String.format(
+                    "Found more than one result for UUID %s.",
+                    id.key.toString()
+                ),
+                ex
+            );
+        }
     }
 
     @Override