首先，看看google对于SubscriptionController类的说明
/**
* SubscriptionController to provide an inter-process communication to
* access Sms in Icc.
*
* Any setters which take subId, slotId or phoneId as a parameter will throw an exception if the
* parameter equals the corresponding INVALID_XXX_ID or DEFAULT_XXX_ID.
*
* All getters will lookup the corresponding default if the parameter is DEFAULT_XXX_ID. Ie calling
* getPhoneId(DEFAULT_SUB_ID) will return the same as getPhoneId(getDefaultSubId()).
*
* Finally, any getters which perform the mapping between subscriptions, slots and phones will
* return the corresponding INVALID_XXX_ID if the parameter is INVALID_XXX_ID. All other getters
* will fail and return the appropriate error value. Ie calling getSlotId(INVALID_SUBSCRIPTION_ID)
* will return INVALID_SLOT_ID and calling getSubInfoForSubscriber(INVALID_SUBSCRIPTION_ID)
* will return null.
*
*/
public class SubscriptionController extends ISub.Stub {
......
}/*
