Question

I am using a terminal emulator library to create a terminal and then I use it to send the data entered over serial to a serial device. Not that I have that working I want to create some other graphical interface, maybe just a textBox, on screen which shows a briefer version of the results for the user alongside the full version in the terminal. They can just glance at this for a quicker view of results. I’m wondering how to parse it best. When I send a command a byte array is sent back to me containing data like this as an example of one set of results:

Interface           IP-Address       Status                Protocol        
vlan1               192.168.1.1      up                    up  
Fa0/1i              unassigned       administratively down down
Fa0/1o              unassigned       down                  down
Fa1/0               unassigned       down                  down
Fa1/1               unassigned       down                  down
Fa1/2               unassigned       down                  down
Fa1/3               unassigned       down                  down
Fa1/4               unassigned       down                  down
Fa1/5               unassigned       down                  down
Fa1/6               unassigned       down                  down
Fa1/7               unassigned       down                  down
Fa1/8               unassigned       up                    up  
Fa1/9               unassigned       down                  down
Fa1/10              unassigned       up                    up  
Fa1/11              unassigned       down                  down
Gi0                 unassigned       up                    up  
switch# 

How would I parse this? I would like something like “The interface vlan1 is up with an IP of 192.1.1.168” or “the interface Fa1/8 is up with an unassigned IP address.” to appear for the user, just listing the most pertinent data. Would I just say something like:

    if (dataReceived.charAt(i) == 'v'
    && dataReceived.charAt(i + 1) == 'l'
    && dataReceived.charAt(i + 2) == 'a'
    && dataReceived.charAt(i + 3) == 'n')
    && dataReceived.charAt(i + 4) == '1')
    && etc //check i is in bounds, check is the next non-whitespace character a number or a u somehow and so on 
        {
         //do things here
         //print out "The interface vlan1 is up with an IP of 192.1.1.168"
        }

This way seems quite tedious, checking every byte, seeing what the next bytes are and so on. Is this the best/a correct way however?

EDIT: here is a sample I have at the moment, where I am receiving data, and where I am testing it for certain data:

public void onDataReceived(int id, byte[] data) {


            dataReceived = new String(data);


        try {
            dataReceivedByte = dataReceived.getBytes("ASCII");
        } catch (UnsupportedEncodingException e) {
            Log.d(TAG, "exception");
            e.printStackTrace();
        }
        statusBool = true;
        Log.d(TAG, "in data received " + dataReceived);
        ((MyBAIsWrapper) bis).renew(data);


        runOnUiThread(new Runnable(){

            @Override
            public void run() {


            }});
        viewHandler.post(updateView);
    }


Handler viewHandler = new Handler();
    Runnable updateView = new Runnable() {
        @Override

        public void run() {

            mEmulatorView.invalidate();

            if (statusBool == true) {
                for (int i = 1; i < dataReceived.length() - 1; i++) {

                    if (dataReceived.charAt(i) == '>') {

                        Log.d(TAG, "found >");
                        deviceStatus = 0;
                    }
                    if (dataReceived.charAt(i) == '#'
                            && dataReceived.charAt(i - 1) != ')') {

                        Log.d(TAG, "found #");
                        deviceStatus = 1;
                    }
                    if ((i + 1) <= (dataReceived.length())
                            && dataReceived.charAt(i) == ')'
                            && dataReceived.charAt(i + 1) == '#') {

                        Log.d(TAG, "found config )#");
                        deviceStatus = 2;
                    }

                }
                statusBool = false;
                viewHandler.postDelayed(updateView, 1000);

            }
        }
    };

Answer 1

As you are using charAt(), I suppose that dataReceived is a String. If not, it might be convenient to convert the data into a string, as you can then make use of the convenient String methods. You can covnert a byte array to a string using the String(byte[]) constructor.

So, you could also use the contains() method to check if the string contains a particular substring:

if(dataReceived.contains("vlan1")) {
  // do things here
}

Or if you are interested in the location of the substring you can use indexOf().