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gwtgoogle-cloud-datastoreapp-engine-ndb

The error creating app Engine's DataStore Entity within GWT app

I try to create the entity like this:

DatastoreService ds = DatastoreServiceFactory.getDatastoreService();
Entity stock = new Entity("Stock", 1);
stock.setProperty("Stock", "FCB");
ds.put(stock);

but keep getting the error:

No source code is available for type com.google.appengine.api.datastore.DatastoreService; did you forget to inherit a required module?

Solution

  • No source code is available

    GWT transliterate Java to Javascript, reading it's source code and there a limited language support.

    What you're trying to achieve is a Server only operation and you're adding this operation within the client code, which will run on a browser. Neither GAE allow this or GWT has the source of these classes nor capability to do so.

    Solution

    You need to create a request to your server that will access the DatastoreService , the return the output to the client code. Below a example of a properly architect GWT web application: GWT Diagram