java - First three characters missing from string when send from android via bluetooth

Question

When I send "M" String to the Device I call time function from where I make my String.

Code:

` mManButton.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {

            man = 1;

            clearScreen();

            mManButton.setBackgroundResource(R.color.button_pressed);
            mStartButton.setBackgroundResource(R.color.button_default);
            mCalButton.setBackgroundResource(R.color.button_default);
            mTestButton.setBackgroundResource(R.color.button_default);
            mLinearButtton.setBackgroundResource(R.color.button_default);
            mAutoButton.setBackgroundResource(R.color.button_default);
            // Send a message using content of the edit text widget

            sendMessage("M");
            time();
        }

    });`

Then the time() function is called. Here if my day is Monday then the variable day is set to 1. That means in this function I am creating a String which has Date Format values in it. This string starts from "A" and ends with "B".

Code :

 private void time()
{
    int day = 0;
    Date now = new Date();
    String sdf = new SimpleDateFormat("EEEE", Locale.ENGLISH).format(now);

    switch(sdf){
        case ("Monday"):
            day = 1;
            break;
        case("Tuesday"):
            day = 2;
            break;
        case ("Wednesday"):
            day = 3;
            break;
        case ("Thursday"):
            day = 4;
            break;
        case("Friday"):
            day = 5;
            break;
        case ("Saturday"):
            day = 6;
            break;
        case("Sunday"):
            day = 7;
            break;
    }

    int mm = Calendar.getInstance().get(Calendar.MINUTE);
    int HH = Calendar.getInstance().get(Calendar.HOUR_OF_DAY);
    int dd = Calendar.getInstance().get(Calendar.DAY_OF_MONTH);
    int MM = Calendar.getInstance().get(Calendar.MONTH)+1;
    int yy = Calendar.getInstance().get(Calendar.YEAR)%100;

    if(mm<10) {
        String time1 = "A" + "0" + mm + HH + "0" + day + dd + MM + yy + "B"; //suppose time1 = A041303211216B
        tv7.setText("Please Wait..");
        int p = 0;
        while (p < time1.length())
        {
            char zx = time1.charAt(p);
            String xz = String.valueOf(zx);
            sendMessage(xz);
            p++;
        }
    }
    else if(mm>=10) {
        String time2 = "A" + mm + HH + "0" + day + dd + MM + yy + "B"; **//suppose time2 = A151303211216B**
        tv7.setText("Please Wait..");
        int k = 0;
        while (k < time2.length())
        {
            char zx = time2.charAt(k);
            String xz = String.valueOf(zx);
            sendMessage(xz);
            k++;
        }
    }
}

When the string is created I send each characters of the string to sendMessage().

Code :

private void sendMessage(String message) {
    // Check that we're actually connected before trying anything
    if (mChatService.getState() !=
            com.example.hasani.bluetoothterminal.BluetoothChatService.STATE_CONNECTED) {
        Toast.makeText(getActivity(), R.string.not_connected, Toast.LENGTH_SHORT).show();
        mStartButton.setBackgroundResource(R.color.button_default);
        mCalButton.setBackgroundResource(R.color.button_default);
        mTestButton.setBackgroundResource(R.color.button_default);
        mManButton.setBackgroundResource(R.color.button_default);
        mAutoButton.setBackgroundResource(R.color.button_default);
        return;
    }

    // Check that there's actually something to send
    if (message.length() > 0) {
        // Get the message bytes and tell the BluetoothChatService to write
        byte[] send = message.getBytes();
        mChatService.write(send);

        // Reset out string buffer to zero and clear the edit text field
        mOutStringBuffer.setLength(0);
    }
}

The write function.

Code :

public void write(byte[] out) {
    // Create temporary object
    ConnectedThread r;
    // Synchronize a copy of the ConnectedThread
    synchronized (this) {
        if (mState != STATE_CONNECTED) return;
        r = mConnectedThread;
    }
    // Perform the write unsynchronized
    r.write(out);
}

The wite in ConnectedThread Code :

public void write(byte[] buffer) {
        try {
            mmOutStream.write(buffer);

            // Share the sent message back to the UI Activity
            mHandler.obtainMessage(com.example.hasani.bluetoothterminal.Constants.MESSAGE_WRITE, -1, -1, buffer)
                    .sendToTarget();
        } catch (IOException e) {
            Log.e(TAG, "Exception during write", e);
        }
    }

As there is a role of Handler in it. The issue is when debugging step by step, each character is sent to the other Device and that device receives each and every string from "A" to "B", thus there is no problem.

But when i run My android app, after sending "M", the time() function is called and the String is sent but the first three characters of the string i.e; "Amm" is not received by the device. I still don't understand what is causing the problem. Please Help!. Will be appreciated. Thank You!

Answer 1

Ohkay wait!!! I got the solution. In case if someone go through the same kind of situation. In my onClickListener I call my time() function after a 5 second delay using a second handler.

My onClickListener code is :

mManButton.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {

            man = 1;
            linear = 0;
            auto = 0;
            cal = 0;
            test = 0;
            linear = 0;
            clearScreen();

            mManButton.setBackgroundResource(R.color.button_pressed);
            mStartButton.setBackgroundResource(R.color.button_default);
            mCalButton.setBackgroundResource(R.color.button_default);
            mTestButton.setBackgroundResource(R.color.button_default);
            mLinearButtton.setBackgroundResource(R.color.button_default);
            mAutoButton.setBackgroundResource(R.color.button_default);
            // Send a message using content of the edit text widget

            sendMessage("M");
            tv7.setText("Please wait....");
            Handler handler = new Handler();
            handler.postDelayed(new Runnable() {
                @Override
                public void run() {
                    time();
                }
            },5000);
        }

    });

My time() function is :

private void time() {
    int day = 0;
    Date now = new Date();
    String sdf = new SimpleDateFormat("EEEE", Locale.ENGLISH).format(now);

    switch (sdf) {

        case ("Monday"):
            day = 1;
            break;
        case ("Tuesday"):
            day = 2;
            break;
        case ("Wednesday"):
            day = 3;
            break;
        case ("Thursday"):
            day = 4;
            break;
        case ("Friday"):
            day = 5;
            break;
        case ("Saturday"):
            day = 6;
            break;
        case ("Sunday"):
            day = 7;
            break;
    }

    int mm = Calendar.getInstance().get(Calendar.MINUTE);
    int HH = Calendar.getInstance().get(Calendar.HOUR_OF_DAY);
    int dd = Calendar.getInstance().get(Calendar.DAY_OF_MONTH);
    int MM = Calendar.getInstance().get(Calendar.MONTH)+1;
    int yy = Calendar.getInstance().get(Calendar.YEAR)%100;


    String A = "A";
    String min = String.format("%02d",mm);
    String hour = String.format("%02d",HH);
    String d = String.format("%02d",day);
    String date = String.format("%02d",dd);
    String month = String.format("%02d",MM);
    String year = String.format("%02d",yy);
    String B = "B";

    String time2 = A+min+hour+d+date+month+year+B;
    sendMessage(time2);
}

Now i can receive correct data as I required. My application works like a charm.