【Android架构Telephony篇】Subscription和SubscriptionManager
一台设备可以有多张SIM卡，最典型的例子就是眼下流行的“双卡双待”。每一张SIM卡都对应一个Subscription，找不到对应的中文术语，我们求助下翻译软件。
Subscription：谷歌翻译为“订阅”，依旧不明觉厉；继续翻译：
订阅（Subscription）：定义了请求者与业务或业务操作之间的关联关系。只有定义了订阅关系，才能通过业务策略，控制请求者对某个业务的访问行为。
我们用谁家的SIM卡就相当于订阅(Subscription)谁家的业务，对应的SIM卡的信息就是Subscription Information，比如运营商名称、MNC、MCC等，多张SIM卡就有多个Subscription Information。
在Android中，针对上述功能的实现、管理就是SubscriptionManager，表现到软件上就是：
各个类的实现比较简单自行参看源码。
SubscriptionManager作用有三个：
- 获取Subscription信息
- 更改Subscription某些信息
- 提供OnSubscriptionsChangedListener监听器，方便其他应用监听Subscription的状态改变
是时候看下Subscription了。
Subscription内容：
public class SubscriptionInfo implements Parcelable {
/**
* Subscription Identifier, this is a device unique number
* and not an index into an array
*/
private int mId;
/**
* The GID for a SIM that maybe associated with this subscription, empty if unknown
*/
private String mIccId;
/**
* The index of the slot that currently contains the subscription
* and not necessarily unique and maybe INVALID_SLOT_ID if unknown
*/
private int mSimSlotIndex;
/**
* The name displayed to the user that identifies this subscription
*/
private CharSequence mDisplayName;
/**
* String that identifies SPN/PLMN
* TODO : Add a new field that identifies only SPN for a sim
*/
private CharSequence mCarrierName;
/**
* The source of the name, NAME_SOURCE_UNDEFINED, NAME_SOURCE_DEFAULT_SOURCE,
* NAME_SOURCE_SIM_SOURCE or NAME_SOURCE_USER_INPUT.
*/
private int mNameSource;
/**
* A number presented to the user identify this subscription
*/
private String mNumber;
/**
* Data roaming state, DATA_RAOMING_ENABLE, DATA_RAOMING_DISABLE
*/
private int mDataRoaming;
/**
* Mobile Country Code
*/
private int mMcc;
/**
* Mobile Network Code
*/
private int mMnc;
/**
* ISO Country code for the subscription's provider
*/
private String mCountryIso;
}
SubscriptionController: [getSubInfoRecord] id:2 iccid:898600020XXXXXXXXXXX simSlotIndex:0 displayName:中国移动 carrierName:No service. nameSource:0 iconTint:-16746133 dataRoaming:0 mcc:460 mnc:2 countIso:cn看下对应的术语：
ICCID：Integrate circuit card identity 集成电路卡识别码（固化在手机SIM卡中）。ICCID为IC卡的唯一识别号码，共有20位数字组成：
PLMN：Public Land Mobile Network 公共陆地移动网，一般某个国家的一个运营商对应一个PLMN
SPN：Service Provider Name 运营商名称
MCC：Mobile Country Code，移动国家码，MCC的资源由国际电联（ITU）统一分配和管理，唯一识别移动用户所属的国家，共3位，中国为460
MNC：Mobile Network Code 移动网络号码，用于识别移动用户所归属的移动通信网，2~3位数字组成，如中国移动系统使用00、02、04、07，中国联通GSM系统使用01、06、09
ISO country code: 国际上不同国家的ISO编码，比如我们国家：
那么问题来了，这些信息从哪来？
对于SubscriptionController来说，它是从数据库telephony.db的siminfo表中读取：
/data/data/com.android.providers.telephony/databases
siminfo表的创建：
TelephonyProvider.java (g:\rk3288-android6.0f\packages\providers\telephonyprovider\src\com\android\providers\telephony) 105530 2017-04-24
private void createSimInfoTable(SQLiteDatabase db) {
db.execSQL("CREATE TABLE " + SIMINFO_TABLE + "("
+ SubscriptionManager.UNIQUE_KEY_SUBSCRIPTION_ID + " INTEGER PRIMARY KEY AUTOINCREMENT,"
+ SubscriptionManager.ICC_ID + " TEXT NOT NULL,"
+ SubscriptionManager.SIM_SLOT_INDEX + " INTEGER DEFAULT " + SubscriptionManager.SIM_NOT_INSERTED + ","
+ SubscriptionManager.DISPLAY_NAME + " TEXT,"
+ SubscriptionManager.CARRIER_NAME + " TEXT,"
+ SubscriptionManager.NAME_SOURCE + " INTEGER DEFAULT " + SubscriptionManager.NAME_SOURCE_DEFAULT_SOURCE + ","
+ SubscriptionManager.COLOR + " INTEGER DEFAULT " + SubscriptionManager.COLOR_DEFAULT + ","
+ SubscriptionManager.NUMBER + " TEXT,"
+ SubscriptionManager.DISPLAY_NUMBER_FORMAT + " INTEGER NOT NULL DEFAULT " + SubscriptionManager.DISPLAY_NUMBER_DEFAULT + ","
+ SubscriptionManager.DATA_ROAMING + " INTEGER DEFAULT " + SubscriptionManager.DATA_ROAMING_DEFAULT + ","
+ SubscriptionManager.MCC + " INTEGER DEFAULT 0,"
+ SubscriptionManager.MNC + " INTEGER DEFAULT 0,"
+ SubscriptionManager.CB_EXTREME_THREAT_ALERT + " INTEGER DEFAULT 1,"
+ SubscriptionManager.CB_SEVERE_THREAT_ALERT + " INTEGER DEFAULT 1,"
+ SubscriptionManager.CB_AMBER_ALERT + " INTEGER DEFAULT 1,"
+ SubscriptionManager.CB_EMERGENCY_ALERT + " INTEGER DEFAULT 1,"
+ SubscriptionManager.CB_ALERT_SOUND_DURATION + " INTEGER DEFAULT 4,"
+ SubscriptionManager.CB_ALERT_REMINDER_INTERVAL + " INTEGER DEFAULT 0,"
+ SubscriptionManager.CB_ALERT_VIBRATE + " INTEGER DEFAULT 1,"
+ SubscriptionManager.CB_ALERT_SPEECH + " INTEGER DEFAULT 1,"
+ SubscriptionManager.CB_ETWS_TEST_ALERT + " INTEGER DEFAULT 0,"
+ SubscriptionManager.CB_CHANNEL_50_ALERT + " INTEGER DEFAULT 1,"
+ SubscriptionManager.CB_CMAS_TEST_ALERT + " INTEGER DEFAULT 0,"
+ SubscriptionManager.CB_OPT_OUT_DIALOG + " INTEGER DEFAULT 1"
+ ");");
if (DBG) log("dbh.createSimInfoTable:-");
}那么又要问了，数据库的数据从哪来？自然从SIM中读取的了。
怎么读？通过AT指令读！
怎么通过AT指令读？说过了。