Hide your troops in sanctuary - in the castle

One thing you can do is to try to talk to the player that is attacking you. Call them to stop attacking you, Little Empire Mojo  because you're just like everyone else who wants to play the game and not get bullied.

Ask politely, without threatening. If you make empty threats, they may be recognized and probably result in further attacks.
If the attacker is a member of an honorable alliance, speak with the chancellor of that alliance. Buy Little Empire Mojo  Alliances are usually responsible for the conduct of their members. Again, be polite.

If they are from a dishonorable alliance or are persistently farming you and won't stop,  Cheap Little Empire Mojo then the are a few things to do to annoy them greatly and should stop them:

Hide your troops in sanctuary - in the castle
Keep resource levels below storehouse levels. A level 10 storehouse with level 10 shrinking powder keeps 2 million of each resource safe, excluding gold.

Keep building; don't leave the game - that's what they might want you to do.Pikemen are awesome defenders so build lots of them along with heavy cavalry and archers.

Walls will be knocked down but can be rebuilt, Cheap Little Empire Mojo  so if you build these the attackers will lose troops attacking you and it may stop them.

If nobody likes them by the time you have grown enough and got plenty of heavy cavalry, pikes and archers they will have been farmed to oblivion so portal by them with all your cities, farm them and don't stop.