SMS注册与接收短信

 Android4.2

 在Android4.0中，Phone应用的Application类PhoneApp的onCreate方法中调用了

PhoneFactory.makeDefaultPhones(this);

而在4.2中此方法被移到了PhoneGlobals中，PhoneGlobals类继承自ContextWrapper。

在PhoneFactory的makeDefaultPhone方法中初始化了RIL类的静态对象sCommandsInterface与Phone的静态对象sProxyPhone。

RIL构造时判断出手机网络良好就会启动一个线程，线程的Runnable对象是RILReceiver的对象。在run方法中构建Sockect并向下层发起连接

s = new LocalSocket();
l = new LocalSocketAddress(SOCKET_NAME_RIL,
LocalSocketAddress.Namespace.RESERVED);
s.connect(l);

如果连接不上每隔4秒重连一次。如果连接正常，则获取流，调用readRilMessage(is, buffer)方法返回除去开头4个字节外能从流中获取的字节数并把获取的字节存于8k大小限制的buffer中，如果读不到任何字节返回-1。如果返回值为-1，则跳出处理流程，重新进入for循环，否则把获取的字节存于Parcel对象中并调用processResponse(p)处理获取到的数据。

private void
processResponse (Parcel p) {
int type;

type = p.readInt();

if (type == RESPONSE_UNSOLICITED) {
processUnsolicited (p);
} else if (type == RESPONSE_SOLICITED) {
processSolicited (p);
}

releaseWakeLockIfDone();
}

接下来读取4个代表类型的字节。走if流程processUnsolicited (p)。

接下来再读取4个字节的int数据代表事件类型，接收短信走RIL_UNSOL_RESPONSE_NEW_SMS（1003）流程

case RIL_UNSOL_RESPONSE_NEW_SMS: ret =  responseString(p); break;

protected Object
responseString(Parcel p) {
String response;

response = p.readString();

return response;
}

获取数据中的String后继续处理

case RIL_UNSOL_RESPONSE_NEW_SMS: {
if (RILJ_LOGD) unsljLog(response);

// FIXME this should move up a layer
String a[] = new String[2];

a[1] = (String)ret;

SmsMessage sms;

sms = SmsMessage.newFromCMT(a);
if (mGsmSmsRegistrant != null) {
mGsmSmsRegistrant
.notifyRegistrant(new AsyncResult(null, sms, null));
}
break;

如上：mGsmSmsRegistrant定义在Ril的父类中通过下方法赋对象

public void setOnNewGsmSms(Handler h, int what, Object obj) {
mGsmSmsRegistrant = new Registrant (h, what, obj);
}

mGsmSmsRegistrant的notifyRegistrant方法把得到数据用handler传递出去了，接下来跟踪handler是哪个类传过来的。

在构造Phone对象时

sProxyPhone[i] = new YZPhoneProxy(new TDPhone(context,
sCommandsInterface[i], sPhoneNotifier[i]));

可以看出Ril对象赋给了TDPhone对象，TDPhone对象赋给了YZTPhoneProxy对象。查看TDPhone对象的构造发现其调用了其父类GSMPhone的构造，在GSMPhone构造方法中初始化了SMSDispatcher对象

mSMS = new GsmSMSDispatcher(this, mSmsStorageMonitor, mSmsUsageMonitor);

在GsmSMSDispatcher的构造方法中调用了setOnNewGsmSms方法把自己注册在Ril.java里了。

public GsmSMSDispatcher(PhoneBase phone, SmsStorageMonitor storageMonitor,
SmsUsageMonitor usageMonitor) {
super(phone, storageMonitor, usageMonitor);
mDataDownloadHandler = new UsimDataDownloadHandler(mCm);
mCm.setOnNewGsmSms(this, EVENT_NEW_SMS, null);
mCm.setOnSmsStatus(this, EVENT_NEW_SMS_STATUS_REPORT, null);
mCm.setOnNewGsmBroadcastSms(this, EVENT_NEW_BROADCAST_SMS, null);
}

也就是说Ril类里接收普通短信的数据最终传到了GsmSMSDispatcher类的handleMessage方法里，不过GsmSMSDispatcher的handleMessage没处理，而是在其父类SMSDispatcher的handleMessage方法中处理的。

case EVENT_NEW_SMS:
// A new SMS has been received by the device
if (false) {
Log.d(TAG, "New SMS Message Received");
}

SmsMessage sms;

ar = (AsyncResult) msg.obj;

if (ar.exception != null) {
Log.e(TAG, "Exception processing incoming SMS. Exception:" + ar.exception);
return;
}

sms = (SmsMessage) ar.result;
try {
int result = dispatchMessage(sms.mWrappedSmsMessage);
if (result != Activity.RESULT_OK) {
// RESULT_OK means that message was broadcast for app(s) to handle.
// Any other result, we should ack here.
boolean handled = (result == Intents.RESULT_SMS_HANDLED);
notifyAndAcknowledgeLastIncomingSms(handled, result, null);
}
} catch (RuntimeException ex) {
Log.e(TAG, "Exception dispatching message", ex);
notifyAndAcknowledgeLastIncomingSms(false, Intents.RESULT_SMS_GENERIC_ERROR, null);
}

break;

调用了GsmSMSDispatcher中的dispatchMessage(SmsMessageBase smsb)方法，在此方法中对USIM做了其他处理。判断了系统属性是否允许接收短信，对接收短信的限制可以在这个方法里做。最后调用了SMSDispatcher的dispatchNormalMessage(smsb)方法，在此方法又根据解析数据的来的信息判断流程，最后走到dispatchPdus(byte[][] pdus)方法，此方法发送广播

protected void dispatchPdus(byte[][] pdus) {
Intent intent = new Intent(Intents.SMS_RECEIVED_ACTION);
intent.putExtra("pdus", pdus);
intent.putExtra("format", getFormat());
dispatch(intent, RECEIVE_SMS_PERMISSION);
}

下面就是应用层接收广播与处理得到的数据过程了：
接收广播的是SmsReceiver的子类PrivilegedSmsReceiver，最后又把接收到的Intent传递到SmsReceiverService.class中去处理了

} else if (SMS_RECEIVED_ACTION.equals(action)) {
handleSmsReceived(intent, error);

private void handleSmsReceived(Intent intent, int error) {
SmsMessage[] msgs = Intents.getMessagesFromIntent(intent);
String format = intent.getStringExtra("format");
Uri messageUri = insertMessage(this, msgs, error, format);

if (Log.isLoggable(LogTag.TRANSACTION, Log.VERBOSE) || LogTag.DEBUG_SEND) {
SmsMessage sms = msgs[0];
Log.v(TAG, "handleSmsReceived" + (sms.isReplace() ? "(replace)" : "") +
" messageUri: " + messageUri +
", address: " + sms.getOriginatingAddress() +
", body: " + sms.getMessageBody());
}

if (messageUri != null) {
long threadId = MessagingNotification.getSmsThreadId(this, messageUri);
// Called off of the UI thread so ok to block.
Log.d(TAG, "handleSmsReceived messageUri: " + messageUri + " threadId: " + threadId);
MessagingNotification.blockingUpdateNewMessageIndicator(this, threadId, false);
}
}

handleSmsReceived方法把收到的数据存到数据库里并发收到信息的通知。