Java Google Appengine datastore.get在现有实体上引发EntityNotFoundException

Question

Looking for ideas on How could it be that I am getting an EntityNotFoundException when trying to get an entity that I know exists by its key.

As you can see in the screenshot I have an entity of kind "Qualifier" that has an ID/Name of 99_999_9993#5678 but getting an exception saying "No entity was found matching the key: Qualifier("99_999_9993#5678")"

I don't think that it is relevant but just for completeness...: The entity is created inside a transaction and also has an ancestor (Entity Group). The get request is a simple non transnational get based on a manually created key.

Any idea on why do I get this EntityNotFoundException instead of getting the entity ?

Answer 1

It turns out that what I though was not relevant was actually very relevant. When I created the entity I created a key for its ancestor using the KeyFactory but when I was getting it I only used its own part of the key.

As soon as I changed it to use

Key groupKey=KeyFactory.createKey(Kinds.Group, group_id);
Key key=KeyFactory.createKey(groupKey,Kinds.Qualifier, qualifier_id );

instead of

Key key=KeyFactory.createKey(Kinds.Qualifier, qualifier_id );

It started returning my Entity as expected.

so basically its important to note that the Datastore Viewer ID/Name shows only the local part of the keyname, ignoring any indication of the fact that there is an ancestor (Entity Group)...