Persisting Blobs using Objectify

Question

Although I know there is already a Blob service for Appengine, I want to experiment on storing big blobs within the datastore.

Basically I am trying to persist this object using Objectify:

BigBlob.java

BigBlobFragments.java

However, appengine is complaining that: "BigBlobFragment is not a supported property type"

For the BigBlob type I created a DAO class with CRUD operation and registed the type like this:

static {
    ObjectifyService.register(BigBlob.class);
    //ObjectifyService.register(BigBlobFragment.class);
}

protected BigblobDaoImpl() {
    super(BigBlob.class);
}

I actually also have tried registering BigBlobFragment.

Hopefully someone can share some ideas on how to actually persist Big blobs and fragments using Objectify.

koma koma · Accepted Answer · 2012-05-21T08:50:28

I have not used Blobs myself but I noticed you have @PersistenceCapable above your entities... that should be @Entity.

import com.googlecode.objectify.annotation.Entity;

Then you should be able to register your entity with Objectify.

ObjectifyService.register(BigBlob.class);

Persisting Blobs using Objectify

2 Answers