General :: How To Select Preferred Network Operators Automatically From Device

I want to select preferred network operators automatically from device. After I search for it, I found following:

Code:
final int EVENT_AUTO_SELECT_DONE = 300;
Message msg = mHandler.obtainMessage(EVENT_AUTO_SELECT_DONE);
phone.setNetworkSelectionModeAutomatic(msg);

So I need an instance of class "Phone". I tried this:

Code:
String phoneFactoryName = "com.android.internal.telephony.PhoneFactory";
String phoneName = "com.android.internal.telephony.Phone";
Class phoneFactoryClass = Class.forName(phoneFactoryName);
Class phoneClass = Class.forName(phoneName);
Method getDefaultPhone = phoneFactoryClass.getMethod("getDefaultPhone");
Object phoneObject = getDefaultPhone.invoke(null);

But the method "getDefaultPhone" can only called by looper.

Next I tried this:

Code:
String phoneAppName = "com.android.phone.PhoneApp";
Class phoneAppClass = Class.forName(phoneAppName);
Method getInstanceMethod = phoneAppClass.getMethod("getInstance");
Object phoneObject = getInstanceMethod.invoke(null);

But I get a ClassNotFoundException.