I have a Jframe that includes a Jspinner. When the JSpinner is increased a new JTextField is created in my panel headerPanel. The script creates the textboxes with an integer attached to their variable name (tFrame0, tFrame1, and so on).

        spinner = new JSpinner();
        spinner.addContainerListener(new ContainerAdapter() {
            @Override
            public void componentAdded(ContainerEvent arg0) {
                boxesChanged();
            }
        });
        spinner.addChangeListener(new ChangeListener() {
            public void stateChanged(ChangeEvent arg0) {
                int spinnerValue = (Integer) spinner.getValue();
                if (spinnerValue == headerPanel.getComponentCount()) {
                    System.out.println("Error, spinner shouldn't change to same value");
                }

                if (spinnerValue < headerPanel.getComponentCount()) {
                    headerPanel.removeAll();
                }

                while (spinnerValue > headerPanel.getComponentCount()) {
                    boxesChanged();

                    // frame.getContentPane().add(tField);
                    frame.revalidate(); // For JDK 1.7 or above.
                    // frame.getContentPane().revalidate(); // For JDK 1.6 or below.
                    frame.repaint();
                }
            }
        });

Now I'm trying to loop through my code based on the number of components in my headerPanel but I don't know how to append my for loop int i to a variable name.

Variables

    Public JTextField() tField;
    Public String nameTField = "tFrame";
    Public Object[] inputData;


Creating the text boxes

    public void boxesChanged() {
        tField = new JTextField();
        tField.setName(nameTField + (headerPanel.getComponentCount()));
        headerPanel.add(tField);
    }

Loop attempt (Located in a separate class with access to the GUI)

    int hp = headerPanel.getComponentCount();
    inputData = new Object[hp];
    for (int i = 0; i < hp; i++) {
        tField = new JTextField();
        tField.setName(nameTField + i);
        inputData[i] = tField.getText();
    }

EDIT

I was able to make some headway with this https://stackoverflow.com/questions/24642059/for-loop-output-in-jframe?fbclid=IwAR1piMmk8EjygobXdxkyxfM9idA5pCh4WJrpBx9QINbsMcmc5MvaUZ3gb0I. When creating the textboxes, I can assign a Document Listener to them and then they are able to pass me information. I'm still having some issues with how I can assign each input from these to my for loop however.

    public void boxesChanged() {
    tField = new JTextField();
    tField.setName(nameTField + (headerPanel.getComponentCount()));
    tField.getDocument().addDocumentListener(new DocumentListener(){
          public void changedUpdate(DocumentEvent e) {
            warn();
          }
          public void removeUpdate(DocumentEvent e) {
            warn();
          }
          public void insertUpdate(DocumentEvent e) {
            warn();
          }

          public void warn() {
             if(tField.getText()!=null) {
                 System.out.println(tField.getText());
             }
          }
    });

    headerPanel.add(tField);

    }

EDIT 2

I've managed to make a change that adds each textfields information to my inputData Object[], but only if I add data sequentially (tField0 must be filled out, then tField1, etc).

For some reason each time I add a new JTextField it changes the document listener to that field only, even though I create the document listener in each new JTextField.

        public void boxesChanged() {
        int hp = headerPanel.getComponentCount();

        tField = new JTextField();
        textFieldList.add(tField);
        tField.setName(nameTField + hp);

        tField.getDocument().addDocumentListener(new DocumentListener() {

            public void changedUpdate(DocumentEvent e) {
                warn();
            }

            public void removeUpdate(DocumentEvent e) {
                warn();
            }

            public void insertUpdate(DocumentEvent e) {
                warn();
            }

            public void warn() {
                int digits = 1;

                if (hp > 9) {
                    digits = 2;
                }

                String getFieldString;
                int getFieldNum;

                getFieldString = tField.getName().substring(tField.getName().length() - digits);

                getFieldNum = Integer.parseInt(getFieldString);

                if (tField.getText() != null) {
                    Object[] currentData = new Object[getFieldNum + 1];
                    currentData[getFieldNum] = tField.getText();

                    inputData[getFieldNum] = tField.getText();

                    for (int i = 0; i < inputData.length; i++) {
                        if (inputData[i] != null) {
                            System.out.println("for i = " + i + ": " + inputData[i]);
                        }

                    }
                }
            }
        });


With this setup if I set the default JTextField to "Box 1" my console output will look like this.

    for i = 0: B
    for i = 0: Bo
    for i = 0: Box
    for i = 0: Box
    for i = 0: Box 1

If I create the second JTextField and then type in "Box 2" in that field it will output like this

    //Same as above
    for i = 0: Box 1
    for i = 1: B
    for i = 0: Box 1
    for i = 1: Bo
    for i = 0: Box 1
    for i = 1: Box
    for i = 0: Box 1
    for i = 1: Box
    for i = 0: Box 1
    for i = 1: Box 2

However say I decide to change the boxes to "Box 0" and "Box 1" my console after making both of these changes will output this.

    //Same as above
    for i = 0: Box 1 //Deleted "1" from box 1
    for i = 1: Box 2 //Deleted "1" from box 1
    for i = 0: Box 1 //Added "0" to former box 1
    for i = 1: Box 2 //Added "0" to former box 1
    for i = 0: Box 1 //Deleted 2 from box 2
    for i = 1: Box //Deleted 2 from box 2
    for i = 0: Box 1 //Added 1 to former box 2
    for i = 1: Box 1 //Added 1 to former box 2

If I were to keep going and add a 3rd JTextField etc. only the last created JTextField will show a change in output on the console.

EDIT 3

I have managed to pass the code along a little further now. Now I can store all of my data properly within an ArrayList that will hold my data, but only if I enter my data sequentially.

Variables

    Public JTextField() tField; //textField element is public and created in boxesChanged()
    Public String nameTField = "tFrame"; //Name of TextField before appending variable in spinner
    Public Object[] headerData; //inputData changed to headerData in Edit 3.
    private ArrayList<JTextField> textFieldList = new ArrayList<JTextField>(); //ArrayList that holds JTextFields
    private JPanel headerPanel; //Panel that holds JTextFields


My Spinner

    spinner = new JSpinner(); //New spinner
        spinner.addContainerListener(new ContainerAdapter() {
            @Override
            public void componentAdded(ContainerEvent arg0) { //On creation Spinner value is 1, so runs boxesChanged() to set the first JTextFrame
                boxesChanged();
            }
        });
        spinner.addChangeListener(new ChangeListener() {
            public void stateChanged(ChangeEvent arg0) { //Each time the spinner changes
                int spinnerValue = (Integer) spinner.getValue();
                if (spinnerValue == headerPanel.getComponentCount()) {
                    System.out.println("Error, spinner shouldn't change to same value"); //Was reaching this during some debuging earlier, but not recently
                }

                if (spinnerValue < headerPanel.getComponentCount()) {
                    headerPanel.removeAll(); //removes all existing JTextFields
                }

                while (spinnerValue > headerPanel.getComponentCount()) { //Populates headerPanel with JTextFields until spinnerValue == headerPanel.getComponentCount
                    boxesChanged();

                    frame.revalidate();
                    frame.repaint();
                }
            }
        });

My boxesChanged() method

        public void boxesChanged() { //Runs whenever spinner value != number of JTextPanels in headerPanel
        int hp = headerPanel.getComponentCount();

        tField = new JTextField(); //Create JTextField
        textFieldList.add(tField); //adds the current JTextField to ArrayList<JTextField> textFieldList
        tField.setName(nameTField + hp); //sets name of current JTextField to String nameTField + current JTextPanelCount (tFrame0, tFrame1, ...)

        tField.getDocument().addDocumentListener(new DocumentListener() { //Adds a listener to each instance of JTextField

            //If any changes to JTextField, runs warn()
            public void changedUpdate(DocumentEvent e) {
                warn();
            }

            public void removeUpdate(DocumentEvent e) {
                warn();
            }

            public void insertUpdate(DocumentEvent e) {
                warn();
            }

            public void warn() {

                int digits = 1; //sets the number of digits to subtract from substring

                if (hp > 9) { //if >9 uses 2 didgits, Spinner max is 100, starting at 0, so 99 is max
                    digits = 2;
                }

                String getFieldString; //String used to hold substring
                int getFieldNum; //int for parseInt of getFieldString

                getFieldString = tField.getName().substring(tField.getName().length() - digits); //Gets the last digit(s) from tField.getName

                getFieldNum = Integer.parseInt(getFieldString); //Parses substring into int

                headerData = new Object[hp + 1]; //Create headerData with size of number of JTextField +1 (if 0, will instantiate a null array)

                if (tField.getText() != null) { //null check

                    headerData[getFieldNum] = tField.getText(); //sets the headerData value to current JTextField's text

                    for (int i = 0; i < textFieldList.size(); i++) { //Loop through to see if each text field list contains correct data
                        System.out.println("TFL i :" + i + " " + textFieldList.get(i).getText());
                    }
                }
            }
        });

        headerPanel.add(tField); //Accidentally left this part out of the previous edit, hope it wasn't what was causing my issue

    }

With this setup if I set the default JTextField to "Box 1" my console output will look like this.

    TFL i :0 B
    TFL i :0 Bo
    TFL i :0 Box
    TFL i :0 Box
    TFL i :0 Box 1
    TFL i :0 Box 1
    TFL i :1 B
    TFL i :0 Box 1
    TFL i :1 Bo
    TFL i :0 Box 1
    TFL i :1 Box
    TFL i :0 Box 1
    TFL i :1 Box
    TFL i :0 Box 1
    TFL i :1 Box 2

However, this is only if I add data sequentially (tField0 must be filled out before I increase the spinner, then tField1 must be filled out, increase the spinner, etc.).
Otherwise I get an ArrayIndexOutOfBoundsException at

    headerData[getFieldNum] = tField.getText();


Edit 5

Variables

    private static String nameTField = "tField";

    private Object[] headerData;

    public String name;

    public List<JTextField> findTextFields() {
        List<JTextField> fields = new LinkedList<>();

        Component[] children = headerPanel.getComponents();
        // this is your 'search-loop':
        for (Component child : children) {
            if (child instanceof JTextField) {
                JTextField childField = (JTextField) child;
                name = childField.getName();
                if (name.startsWith(nameTField)) {
                    fields.add(childField);
                }
            }
        }

        return fields;
    }

public static final Pattern POSTFIX_PATTERN = Pattern.compile(nameTField + "(\\d+)");

JSpinner

    spinner = new JSpinner();
    spinner.addContainerListener(new ContainerAdapter() {
        @Override
        public void componentAdded(ContainerEvent arg0) {
            boxesRemoved();
            boxesChanged();
            }
    });
    spinner.addChangeListener(new ChangeListener() {
        public void stateChanged(ChangeEvent arg0) {
            int spinnerValue = (Integer) spinner.getValue();
            if (spinnerValue == headerPanel.getComponentCount()) {
                System.out.println("Error, spinner shouldn't change to same value");
            }

            if (spinnerValue < headerPanel.getComponentCount()) {
                boxesRemoved();
                frame.revalidate();
                frame.repaint();
            }

            while (spinnerValue > headerPanel.getComponentCount()) {
                boxesChanged();

                // frame.getContentPane().add(tField);
                frame.revalidate(); // For JDK 1.7 or above.
                // frame.getContentPane().revalidate(); // For JDK 1.6 or below.
                frame.repaint();
            }
        }
    });

boxesRemoved() method

    public void boxesRemoved() {
        for (JTextField textField : findTextFields()) {
            String name = textField.getName();
            Matcher matcher = POSTFIX_PATTERN.matcher(name);
            if (matcher.matches()) {
                String strPostfix = matcher.group(1);
                int postFixNumeric = Integer.parseInt(strPostfix);

                System.out.println("for postFix = " + postFixNumeric + ": " + textField.getText());
                if (postFixNumeric < findTextFields().size()) {
                    System.out.println("PFN: " + postFixNumeric);
                    System.out.println("FTF: " + findTextFields().size());
                    findTextFields().remove(findTextFields().size() - 1);
                    headerPanel.remove(findTextFields().size() - 1);
                }
            }
        }
    }


boxesChanged() method

    public void boxesChanged() {
        int hp = headerPanel.getComponentCount();

        tField = new JTextField();
        tField.setName(nameTField + hp);
        textFieldList.add(tField);

        tField.getDocument().addDocumentListener(new DocumentListener() {

            public void changedUpdate(DocumentEvent e) {
                warn();
            }

            public void removeUpdate(DocumentEvent e) {
                warn();
            }

            public void insertUpdate(DocumentEvent e) {
                warn();
            }

            public void warn() {

                int digits = 1;

                if (hp > 9) {
                    digits = 2;
                }

                String getFieldString;
                int getFieldNum;

                getFieldString = tField.getName().substring(tField.getName().length() - digits);

                getFieldNum = Integer.parseInt(getFieldString);

                headerData = new Object[hp + 1];

                for (JTextField textField : findTextFields()) {
                    Matcher matcher = POSTFIX_PATTERN.matcher(name);
                    System.out.println(name);
                    if (matcher.matches()) {
                        String strPostfix = matcher.group(1);
                        int postfixNumeric = Integer.parseInt(strPostfix);

                        System.out.println("for postfix = " + postfixNumeric + ": " + textField.getText());
                    } else {
                        System.out.println("matcher error: " + matcher);
                    }
                }
            }
        });

        headerPanel.add(tField);

    }