Play Framework - Saving object state across multiple calls

Question

I have a Play! framework (2.3.7) application that has several routes:

/api/set_x
/api/set_y
/api/set_z
/api/launch

Each one of these calls sets a property in an instance of MyObject . When /api/launch is called, the instance of MyObject is validated and if everything is ok it will be persisted and 200 OK will be returned to the user.

How to I keep the state of the instance across multiple calls until /api/launch is called?

1. Using the session seems bad since in play the session is just a cookie, limited to 4KB.
2. Using the cache - if the cache is evicted I have no way of reconstructing the instance again, which means that the user can supply all the properties but before calling /api/launch the cache was evicted and a bad request instead of OK will be returned to the user.

Is there an elegant way to implement such a thing in Play?

Answer 1

There's no the best solution for your problem and it mostly depends on a specific use case. To keep data between requests you have three possible options:

• Play's session or cookies
• some cache layer
• a database

One of the main feature of Play framework is being stateless on a server side and that should be always in mind while designing an application. So if you are looking for an 'elegant' solution the answer is simple - there's no such. It's all up to a specific case.