Villain is unknown, I have less than 20 hands on him, so no stats. Standard river fold? Line-check?

Full Tilt Poker - No Limit Holdem Ring game - Blinds: $2/$4 - 6 players - Converter

Stack sizes:
UTG: $96.50
Hero: $962.80
CO: $752
Button: $382
SB: $400
BB: $386

Pre-flop: (6 players) Hero is UTG+1 with J J
UTG folds, Hero raises to $14, CO folds, Button calls, 2 folds.

Flop: 3 7 K ($34, 2 players)
Hero bets $28, Button calls.

Turn: 2 ($90, 2 players)
Hero bets $64, Button calls.

River: J ($218, 2 players)
Hero bets $130, Button raises all-in $276, Hero folds.