Getting Distance between players

[Technerder]

Hello, i am relatively new to forge modding (im used to developing server plugins) and i would like to know how to get, the distance between the player with my mod and the other person he is fighting on a server. How would i accomplish this? 

 

Aswell, could someone link me the official javadocs website?

[Abastro]

The hard part will be getting the enemy. How would you define the enemy? The target the player is attacking?

The other part is easy: Entity::getDistanceToEntity(Entity).

 

I don't know about official javadocs, but here's the official documentation for forge: http://mcforge.readthedocs.io/en/latest/