TelephonyManager telMgr = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
int simState = telMgr.getSimState();
switch (simState) {
case TelephonyManager.SIM_STATE_ABSENT:
// do something
break;
case TelephonyManager.SIM_STATE_NETWORK_LOCKED:
// do something
break;
case TelephonyManager.SIM_STATE_PIN_REQUIRED:
// do something
break;
case TelephonyManager.SIM_STATE_PUK_REQUIRED:
// do something
break;
case TelephonyManager.SIM_STATE_READY:
// do something
break;
case TelephonyManager.SIM_STATE_UNKNOWN:
// do something
break;
}