Hello i have object that is created when player joins world/server and i want to use it to create and sync variables per-player how i can make it save and how to sync it with server and with other clients?

Generally speaking: Packets.

 

The real question is: Why are you creating an object to store player variables?  Use Capabilities.

for me using whole object is easier

 

Ok but how to do this?

Whole logic behind it:

 

* EntityPlayer has Capability assigned.

* Data is (on server) created fresh (1st join) or loaded from player's NBT (later joins).

* Data is parsed into your "Object".

* Use PlayerLoggedInEvent to send packet to player that will contain your serialized Object.

* Client handles packet and deserializes it into "Object" on client and puts it in client's Capability of player.

 

Points of interest:

 

* Caps: http://mcforge.readthedocs.org/en/latest/datastorage/capabilities/

* Setting up Caps: https://github.com/MinecraftForge/MinecraftForge/tree/1.9/src/test/java/net/minecraftforge/test

Note: One of them is NoBedTest.

 

* Packets: http://www.minecraftforge.net/forum/index.php/topic,20135.0.html

* In 1.8+: http://greyminecraftcoder.blogspot.com.au/2015/01/thread-safety-with-network-messages.html

 

* Forge Events: @SubscribeEvent and registering (google).

* PlayerLoggedInEvent

* AttachCapabilityEvent.Entity (or similar name, lookL links before).

 

* NBT de-/serialization (Capability storage).

 

Other: This will take hours to write it well, and only if you know Java and had experience with some of it in past.