Automatycznie dodawanie się kilku pracowników do listy

Używam do skanowania kodu Google Qr Google Vison, ale mam mały problem. Podczas skanowania kodu QR automatycznie zapisuje mi się kilka obiektów. Jak zrobic zeby podczas skanowania QR kodu zapisało się jedne dane

public class Employee {

    private String firstName;
    private String lastName;
    private String age;

    public Employee(String firstName, String lastName, String age) {
        super();
        this.firstName = firstName;
        this.lastName = lastName;
        this.age = age;
    }


    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        this.age = age;
    }

I use to scan Qr Code Google Vison but I have a little problem. When scan QR Code It automatically saves me several objects the same. How do if you scan QR Code read one data.

For example:

my class Employee

model object Employee

public class Employee {

private String firstName;
private String lastName;
private String age;

public Employee(String firstName, String lastName, String age) {
    super();
    this.firstName = firstName;
    this.lastName = lastName;
    this.age = age;
}


public String getFirstName() {
    return firstName;
}

public void setFirstName(String firstName) {
    this.firstName = firstName;
}

public String getLastName() {
    return lastName;
}

public void setLastName(String lastName) {
    this.lastName = lastName;
}

public String getAge() {
    return age;
}

public void setAge(String age) {
    this.age = age;
}

}

ScanQrCode.class

metoda która skanuje OR Kod

private ArrayList<Employee> employeeList = new ArrayList<Employee>();

...
//this method with read vale with QR Code

 @Override
            public void receiveDetections(Detector.Detections<Barcode> detections) {
                final SparseArray<Barcode> barcodes = detections.getDetectedItems();
                if (barcodes.size() != 0) text.post(new Runnable() {
                    @Override
                    public void run() {

                        Vibrator vibrator = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
                        vibrator.vibrate(400);

String name,lastname,age;
String[] dataEmployee = new String[3];
barcodeString = barcodes.valueAt(0).displayValue;

 Pattern p = Pattern.compile("<z[0-9]>(.+?)</z[0-9]>");

      if (p.matcher(barcodeString).matches()) {
          Matcher m = p.matcher(barcodeString);
                 while (m.find()) {
                      dataEmployee[index] = m.group(1);
                      index++;
                  }
name = dataEmployee[0];
lastname = dataEmployee[1];
age = dataEmployee[2];


Employee empmoo = new Employee(name,lastname,age);

employeeList.add(empmoo);
}

Rozumiem, że zapisuje się kilka obiektów z tym samym pracownikiem. Na androidzie się nie znam, ale czy czasami ta metoda nie jest wywoływana kilka razy ? może zamień array list na hash set