发送短信流程一

1.send

packages\apps\Mms\src\com\android\mms\data\WorkingMessage.java

public void send(final String recipientsInUI) {
        long origThreadId = mConversation.getThreadId();
        removeSubjectIfEmpty(true /* notify */);

        // Get ready to write to disk.
        prepareForSave(true /* notify */);

        // We need the recipient list for both SMS and MMS.
        final Conversation conv = mConversation;
        String msgTxt = mText.toString();

        if (requiresMms() || addressContainsEmailToMms(conv, msgTxt)) {
          //彩信
        } else {
            // Same rules apply as above.
            final String msgText = mText.toString();
            new Thread(new Runnable() {
                @Override
                public void run() {
                    preSendSmsWorker(conv, msgText, recipientsInUI);

                    updateSendStats(conv);
                }
            }, "WorkingMessage.send SMS").start();
        }

        // update the Recipient cache with the new to address, if it's different
        RecipientIdCache.updateNumbers(conv.getThreadId(), conv.getRecipients());

        // Mark the message as discarded because it is "off the market" after being sent.
        mDiscarded = true;
    }

2. preSendSmsWorker

packages\apps\Mms\src\com\android\mms\data\WorkingMessage.java

private void preSendSmsWorker(Conversation conv, String msgText, String recipientsInUI) {
        // If user tries to send the message, it's a signal the inputted text is what they wanted.
        UserHappinessSignals.userAcceptedImeText(mActivity);
        //把内容编辑框，联系人输入框，mWorkingMessage等恢复原样
        mStatusListener.onPreMessageSent();

        long origThreadId = conv.getThreadId();

        // Make sure we are still using the correct thread ID for our recipient set.
        long threadId = conv.ensureThreadId(); //最终通过Threads.getOrCreateThreadId创建/查询threadId

        String semiSepRecipients = conv.getRecipients().serialize();

        // recipientsInUI can be empty when the user types in a number and hits send
        if (LogTag.SEVERE_WARNING && ((origThreadId != 0 && origThreadId != threadId) ||
               (!semiSepRecipients.equals(recipientsInUI) && !TextUtils.isEmpty(recipientsInUI)))) {
        }else {
            // just do a regular send. We're already on a non-ui thread so no need to fire
            // off another thread to do this work.
            sendSmsWorker(msgText, semiSepRecipients, threadId);

            // Be paranoid and clean any draft SMS up.
            deleteDraftSmsMessage(threadId); //删除数据库的草稿
        }
    }

3.sendSmsWorker

private void sendSmsWorker(String msgText, String semiSepRecipients, long threadId) {
        String[] dests = TextUtils.split(semiSepRecipients, ";");
        if (LogTag.VERBOSE || Log.isLoggable(LogTag.TRANSACTION, Log.VERBOSE)) {
            Log.d(LogTag.TRANSACTION, "sendSmsWorker sending message: recipients=" +
                    semiSepRecipients + ", threadId=" + threadId);
        }
        MessageSender sender = new SmsMessageSender(mActivity, dests, msgText, threadId);
        try {
            sender.sendMessage(threadId);

             //如果一条会话的信息条数超过限制，会删除掉该会话的时间靠前的信息（数据库通过时间过滤）
            // Make sure this thread isn't over the limits in message count
            Recycler.getSmsRecycler().deleteOldMessagesByThreadId(mActivity, threadId);
        } catch (Exception e) {
            Log.e(TAG, "Failed to send SMS message, threadId=" + threadId, e);
        }
        
        //1.重新查询信息列表
        mStatusListener.onMessageSent();

        MmsWidgetProvider.notifyDatasetChanged(mActivity);
}

4.sendMessage

packages\apps\Mms\src\com\android\mms\transaction\SmsMessageSender.java

public boolean sendMessage(long token) throws MmsException {
        // In order to send the message one by one, instead of sending now, the message will split,
        // and be put into the queue along with each destinations
        return queueMessage(token);
}

5.queueMessage

packages\apps\Mms\src\com\android\mms\transaction\SmsMessageSender.java

private boolean queueMessage(long token) throws MmsException {
        if ((mMessageText == null) || (mNumberOfDests == 0)) {
            // Don't try to send an empty message.
            throw new MmsException("Null message body or dest.");
        }

        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(mContext);
        boolean requestDeliveryReport = prefs.getBoolean(
                MessagingPreferenceActivity.SMS_DELIVERY_REPORT_MODE,
                DEFAULT_DELIVERY_REPORT_MODE);
        //几个收件人，就会存入几条信息（MESSAGE_TYPE_QUEUED = 6）
        for (int i = 0; i < mNumberOfDests; i++) {
            try {
                if (LogTag.DEBUG_SEND) {
                    Log.v(TAG, "queueMessage mDests[i]: " + mDests[i] + " mThreadId: " + mThreadId);
                }
                Sms.addMessageToUri(mContext.getContentResolver(),
                        Uri.parse("content://sms/queued"), mDests[i],
                        mMessageText, null, mTimestamp,
                        true /* read */,
                        requestDeliveryReport,
                        mThreadId);
            } catch (SQLiteException e) {
                if (LogTag.DEBUG_SEND) {
                    Log.e(TAG, "queueMessage SQLiteException", e);
                }
                SqliteWrapper.checkSQLiteException(mContext, e);
            }
        }
        //发送广播
        // Notify the SmsReceiverService to send the message out
        mContext.sendBroadcast(new Intent(SmsReceiverService.ACTION_SEND_MESSAGE,
                null,
                mContext,
                SmsReceiver.class));
        return false;
}

6.onReceive

packages\apps\Mms\src\com\android\mms\transaction\SmsReceiver.java

public void onReceive(Context context, Intent intent) {
  onReceiveWithPrivilege(context, intent, false);
}

7.onReceiveWithPrivilege

packages\apps\Mms\src\com\android\mms\transaction\SmsReceiver.java

protected void onReceiveWithPrivilege(Context context, Intent intent, boolean privileged) {
        // If 'privileged' is false, it means that the intent was delivered to the base
        // no-permissions receiver class.  If we get an SMS_RECEIVED message that way, it
        // means someone has tried to spoof the message by delivering it outside the normal
        // permission-checked route, so we just ignore it.
        if (!privileged && intent.getAction().equals(Intents.SMS_DELIVER_ACTION)) {
            return;
        }

        intent.setClass(context, SmsReceiverService.class);
        intent.putExtra("result", getResultCode());
        beginStartingService(context, intent);
}

8.beginStartingService

packages\apps\Mms\src\com\android\mms\transaction\SmsReceiver.java

public static void beginStartingService(Context context, Intent intent) {
        synchronized (mStartingServiceSync) {
            if (mStartingService == null) {
                PowerManager pm =
                    (PowerManager)context.getSystemService(Context.POWER_SERVICE);
                //PARTIAL_WAKE_LOCK：保持CPU 运转，屏幕和键盘灯有可能是关闭的。
                mStartingService = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,
                        "StartingAlertService");
                mStartingService.setReferenceCounted(false);
            }
            mStartingService.acquire();
            context.startService(intent);
        }
}

9.handleSendMessage

packages\apps\Mms\src\com\android\mms\transaction\SmsReceiverService.java

private void handleSendMessage() {
  if (!mSending) {
    sendFirstQueuedMessage();
  }
}

10.sendFirstQueuedMessage

packages\apps\Mms\src\com\android\mms\transaction\SmsReceiverService.java

public synchronized void sendFirstQueuedMessage() {
        boolean success = true;
        // get all the queued messages from the database
        final Uri uri = Uri.parse("content://sms/queued");
        ContentResolver resolver = getContentResolver();
        //按照时间降序查询所有待发送的短信
        Cursor c = SqliteWrapper.query(this, resolver, uri,
                        SEND_PROJECTION, null, null, "date ASC");   // date ASC so we send out in
                                                                    // same order the user tried
                                                                    // to send messages.
        if (c != null) {
            try {
                if (c.moveToFirst()) {
                    String msgText = c.getString(SEND_COLUMN_BODY);
                    String address = c.getString(SEND_COLUMN_ADDRESS);
                    int threadId = c.getInt(SEND_COLUMN_THREAD_ID);
                    int status = c.getInt(SEND_COLUMN_STATUS);

                    int msgId = c.getInt(SEND_COLUMN_ID);
                    Uri msgUri = ContentUris.withAppendedId(Sms.CONTENT_URI, msgId);

                    SmsMessageSender sender = new SmsSingleRecipientSender(this,
                            address, msgText, threadId, status == Sms.STATUS_PENDING,
                            msgUri);

                    if (LogTag.DEBUG_SEND ||
                            LogTag.VERBOSE ||
                            Log.isLoggable(LogTag.TRANSACTION, Log.VERBOSE)) {
                        Log.v(TAG, "sendFirstQueuedMessage " + msgUri +
                                ", address: " + address +
                                ", threadId: " + threadId);
                    }

                    try {
                        sender.sendMessage(SendingProgressTokenManager.NO_TOKEN);;
                        mSending = true;
                    } catch (MmsException e) {
                        Log.e(TAG, "sendFirstQueuedMessage: failed to send message " + msgUri
                                + ", caught ", e);
                        mSending = false;
                        //发生异常：将短信type更新为MESSAGE_TYPE_FAILED（5），这里的error为1
                        messageFailedToSend(msgUri, SmsManager.RESULT_ERROR_GENERIC_FAILURE);
                        success = false;
                        // Sending current message fails. Try to send more pending messages
                        // if there is any.
                        //发送下一条需要发送的短信
                        sendBroadcast(new Intent(SmsReceiverService.ACTION_SEND_MESSAGE,
                                null,
                                this,
                                SmsReceiver.class));
                    }
                }
            } finally {
                c.close();
            }
        }
        if (success) {
            // We successfully sent all the messages in the queue. We don't need to
            // be notified of any service changes any longer.
            unRegisterForServiceStateChanges();
        }
}

11.sendMessage

packages\apps\Mms\src\com\android\mms\transaction\SmsSingleRecipientSender.java

public boolean sendMessage(long token) throws MmsException {
        if (LogTag.DEBUG_SEND) {
            Log.v(TAG, "sendMessage token: " + token);
        }
        if (mMessageText == null) {
            // Don't try to send an empty message, and destination should be just
            // one.
            throw new MmsException("Null message body or have multiple destinations.");
        }
        SmsManager smsManager = SmsManager.getDefault();
        ArrayList<String> messages = null;
        if ((MmsConfig.getEmailGateway() != null) &&
                (Mms.isEmailAddress(mDest) || MessageUtils.isAlias(mDest))) {
            String msgText;
            msgText = mDest + " " + mMessageText;
            mDest = MmsConfig.getEmailGateway();
            messages = smsManager.divideMessage(msgText);
        } else {
            messages = smsManager.divideMessage(mMessageText); //分割信息
            // remove spaces and dashes from destination number
            // (e.g. "801 555 1212" -> "8015551212")
            // (e.g. "+8211-123-4567" -> "+82111234567")
            mDest = PhoneNumberUtils.stripSeparators(mDest);
            mDest = Conversation.verifySingleRecipient(mContext, mThreadId, mDest);
        }
        int messageCount = messages.size();

        if (messageCount == 0) {
            // Don't try to send an empty message.
            throw new MmsException("SmsMessageSender.sendMessage: divideMessage returned " +
                    "empty messages. Original message is \"" + mMessageText + "\"");
        }
        //更新信息type为MESSAGE_TYPE_OUTBOX（4）
        boolean moved = Sms.moveMessageToFolder(mContext, mUri, Sms.MESSAGE_TYPE_OUTBOX, 0);
        if (!moved) {
            throw new MmsException("SmsMessageSender.sendMessage: couldn't move message " +
                    "to outbox: " + mUri);
        }
        if (LogTag.DEBUG_SEND) {
            Log.v(TAG, "sendMessage mDest: " + mDest + " mRequestDeliveryReport: " +
                    mRequestDeliveryReport);
        }

        ArrayList<PendingIntent> deliveryIntents =  new ArrayList<PendingIntent>(messageCount);
        ArrayList<PendingIntent> sentIntents = new ArrayList<PendingIntent>(messageCount);
        for (int i = 0; i < messageCount; i++) {
            if (mRequestDeliveryReport && (i == (messageCount - 1))) {
                // TODO: Fix: It should not be necessary to
                // specify the class in this intent.  Doing that
                // unnecessarily limits customizability.
                deliveryIntents.add(PendingIntent.getBroadcast(
                        mContext, 0,
                        new Intent(
                                MessageStatusReceiver.MESSAGE_STATUS_RECEIVED_ACTION,
                                mUri,
                                mContext,
                                MessageStatusReceiver.class),
                                0));
            } else {
                deliveryIntents.add(null);
            }
            Intent intent  = new Intent(SmsReceiverService.MESSAGE_SENT_ACTION,
                    mUri,
                    mContext,
                    SmsReceiver.class);

            int requestCode = 0;
            if (i == messageCount -1) {
                // Changing the requestCode so that a different pending intent
                // is created for the last fragment with
                // EXTRA_MESSAGE_SENT_SEND_NEXT set to true.
                requestCode = 1;
                intent.putExtra(SmsReceiverService.EXTRA_MESSAGE_SENT_SEND_NEXT, true);
            }
            if (LogTag.DEBUG_SEND) {
                Log.v(TAG, "sendMessage sendIntent: " + intent);
            }
            sentIntents.add(PendingIntent.getBroadcast(mContext, requestCode, intent, 0));
        }
        try {
            smsManager.sendMultipartTextMessage(mDest, mServiceCenter, messages, sentIntents, deliveryIntents);
        } catch (Exception ex) {
            Log.e(TAG, "SmsMessageSender.sendMessage: caught", ex);
            throw new MmsException("SmsMessageSender.sendMessage: caught " + ex +
                    " from SmsManager.sendTextMessage()");
        }
        if (Log.isLoggable(LogTag.TRANSACTION, Log.VERBOSE) || LogTag.DEBUG_SEND) {
            log("sendMessage: address=" + mDest + ", threadId=" + mThreadId +
                    ", uri=" + mUri + ", msgs.count=" + messageCount);
        }
        return false;
    }

12.sendMultipartTextMessage

frameworks\base\telephony\java\android\telephony\SmsManager.java

public void sendMultipartTextMessage(
            String destinationAddress, String scAddress, ArrayList<String> parts,
            ArrayList<PendingIntent> sentIntents, ArrayList<PendingIntent> deliveryIntents) {
        sendMultipartTextMessageInternal(destinationAddress, scAddress, parts, sentIntents,
                deliveryIntents, true /* persistMessage*/);
}

13.sendMultipartTextMessageInternal

frameworks\base\telephony\java\android\telephony\SmsManager.java

private void sendMultipartTextMessageInternal(
            String destinationAddress, String scAddress, List<String> parts,
            List<PendingIntent> sentIntents, List<PendingIntent> deliveryIntents,
            boolean persistMessage) {
        if (TextUtils.isEmpty(destinationAddress)) {
            throw new IllegalArgumentException("Invalid destinationAddress");
        }
        if (parts == null || parts.size() < 1) {
            throw new IllegalArgumentException("Invalid message body");
        }

        if (parts.size() > 1) {//长信息
            try {
                ISms iccISms = getISmsServiceOrThrow();
                iccISms.sendMultipartTextForSubscriber(getSubscriptionId(),
                        ActivityThread.currentPackageName(),
                        destinationAddress, scAddress, parts,
                        sentIntents, deliveryIntents, persistMessage);
            } catch (RemoteException ex) {
                // ignore it
            }
        } else { //短信息
            PendingIntent sentIntent = null;
            PendingIntent deliveryIntent = null;
            if (sentIntents != null && sentIntents.size() > 0) {
                sentIntent = sentIntents.get(0);
            }
            if (deliveryIntents != null && deliveryIntents.size() > 0) {
                deliveryIntent = deliveryIntents.get(0);
            }
            sendTextMessage(destinationAddress, scAddress, parts.get(0),
                    sentIntent, deliveryIntent);
        }
}