I want to store user messages in a RecyclerView permanently without saving them to the storage. All messages are coming from a server, and I want to permanently save them to a RecyclerView. That is, I want to ensure that RecyclerView messages do not disappear even after the activity is relaunched.
Is there any way for this approach without saving the messages to the storage?
RecyclerViews don't save anything. They're a display element. You have to explicly write an Adapter for every RecyclerView that defines how many elements there are, how to get it's data, and how to display a single item in it. So your question is off from the beginning- RecyclerViews don't store data.
But in order to do what you want, you need some way of getting the data. That can be reading from storage, or a database, or reading from an external source like a website. But something somewhere needs to be storing it in order to keep the data persistent between runs.