What is the best smart home mini PC to use?

Question

Java

The requirements are as follows:
1) Have usrt on board. (Preferably not even one :)
2) Support Java.
3) Ability to work with remote access.
The statement is as follows:
There are several modules in the house, each module is responsible for its field of activity, for example, the module responsible for leakage and shutting off taps.
All modules will have their own Wi-Fi module on board, which will receive and transmit commands from time to time.
Mini PC via RS 232 protocol, will connect via uart to its own Wi-Fi module, mini PC will act as a server for the whole house, must receive and process data coming from other modules using a program specially written for this.
The operator must be able to use this program through remote access.

Answer 1

Raspberry Pi 3

Answer 2

Raspberry Pi 2 is also suitable))