Android programming method to realize phone recording

<uses-permission android:name=".READ_PHONE_STATE"/>
<!-- existSDCardCreate and delete files permissions -->
<uses-permission android:name=".MOUNT_UNMOUNT_FILESYSTEMS"/>
<!-- PastSDCardWrite data permissions -->
<uses-permission android:name=".WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name=".RECORD_AUDIO"/>
<!-- accessinternetPermissions -->
<uses-permission android:name=""/>
<uses-permission android:name=".RECEIVE_BOOT_COMPLETED"/>

public class PhoneListenerService extends Service {
@Override
public void onCreate() {
 TelephonyManager manager = 
   (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
 //The status of the monitored phone (new MyListener(), PhoneStateListener.LISTEN_CALL_STATE);
}
private final class MyListener extends PhoneStateListener {
 private String num;
 private MediaRecorder recorder;
 public void onCallStateChanged(int state, String incomingNumber) {
 switch (state) {
  case TelephonyManager.CALL_STATE_RINGING: /* When the phone comes in */
  num = incomingNumber;
  break;
  case TelephonyManager.CALL_STATE_OFFHOOK: /* When you answer the phone */
  try {
   File file = new File((), num + "_" + () + ".3gp");
   recorder = new MediaRecorder();
   ();//Sound collection source (microphone)   (OutputFormat.THREE_GPP);//Output format   (AudioEncoder.AMR_NB);//Audio encoding method   (());//Output direction   ();
   ();
  } catch (Exception e) {
   ();
  }
  break;
  case TelephonyManager.CALL_STATE_IDLE: /* When there is no state */
  if (recorder != null) {
   ();
   ();
  }
  break;
 }
 }
}
}