◎위챗 : speedseoul
http://programcreek.com/java-api-examples/index.php?api=android.bluetooth.BluetoothHeadset
http://www.tekritisoftware.com/android-call-automation-android-apps
https://code.google.com/p/auto-answer/source/browse/trunk/src/com/everysoft/autoanswer/
http://stackoverflow.com/questions/5320046/how-can-i-answer-a-phone-call-and-hang-it-up
http://stackoverflow.com/questions/9532233/can-not-connect-to-bluetooth-headset-in-android
http://www.yogeshblogspot.com/android-incoming-call-auto-answer/ <<<==good
http://www.javatpoint.com/android-call-state-broadcastreceiver-example <<==good