Choosing Java vs Python on Google App Engine

Question

Currently Google App Engine supports both Python & Java. Java support is less mature. However, Java seems to have a longer list of libraries and especially support for J

Answer 1

An important question to consider in deciding between Python and Java is how you will use the datastore in each language (and most other angles to the original question have already been covered quite well in this topic).

For Java, the standard method is to use JDO or JPA. These are great for portability but are not very well suited to the datastore.

A low-level API is available but this is too low level for day-to-day use - it is more suitable for building 3rd party libraries.

For Python there is an API designed specifically to provide applications with easy but powerful access to the datastore. It is great except that it is not portable so it locks you into GAE.

Fortunately, there are solutions being developed for the weaknesses listed for both languages.

For Java, the low-level API is being used to develop persistence libraries that are much better suited to the datastore then JDO/JPA (IMO). Examples include the Siena project, and Objectify.

I've recently started using Objectify and am finding it to be very easy to use and well suited to the datastore, and its growing popularity has translated into good support. For example, Objectify is officially supported by Google's new Cloud Endpoints service. On the other hand, Objectify only works with the datastore, while Siena is 'inspired' by the datastore but is designed to work with a variety of both SQL databases and NoSQL datastores.

For Python, there are efforts being made to allow the use of the Python GAE datastore API off of the GAE. One example is the SQLite backend that Google released for use with the SDK, but I doubt they intend this to grow into something production ready. The TyphoonAE project probably has more potential, but I don't think it is production ready yet either (correct me if I am wrong).

If anyone has experience with any of these alternatives or knows of others, please add them in a comment. Personally, I really like the GAE datastore - I find it to be a considerable improvement over the AWS SimpleDB - so I wish for the success of these efforts to alleviate some of the issues in using it.