[android] Android: Get checked checkbox values

I need to get checked checkbox values when button clicked. Java Code:

dualcamera1 = (CheckBox)findViewById(R.id.Camera1_DualDisplay);
dualcamera2 = (CheckBox)findViewById(R.id.Camera2_DualDisplay);
dualcamera3 = (CheckBox)findViewById(R.id.Camera3_DualDisplay);
dualcamera4 = (CheckBox)findViewById(R.id.Camera4_DualDisplay);
dualdisplay = (Button)dialog.findViewById(R.id.DisplayDualVideo);