How to call the Loop in Jtextfield

Im having trouble on calling my Loop that i created to be placed on the JTextField. Im only a beginner on GUI so i don't understand what i am missing or lacking . Please Help me.
the program must print a box of period if the user enters 1 and box of asterisk if the user
enters 2. and if the user enters 2 or more an error message will show up.

I re-editted the code sir. this is what i came up, the problem is after i re-enter a number the Jtextarea just keeps stacking the print, it does not refresh i don't know why.Example is if i enter 1 the box of periods will shop then if i enter 2 the box of asterisk appears below the box of periods .and it just keeps on stacking

    import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Box extends JFrame{

    private JLabel numL,resultL;
    private JTextField numTF;
    private JTextArea resultTF;
    private JButton printB,exitB;
    private PrintButtonHandler pbHandler;
    private ExitButtonHandler exitHandler;




    public Box(){

        numL=new JLabel("Enter 1 or 2", SwingConstants.CENTER);
        resultL=new JLabel("Result",SwingConstants.CENTER);
        numTF=new JTextField(20);
        //resultTF=new JTextField(20);
        resultTF = new JTextArea(5,5);

        printB=new JButton("Print");
        pbHandler=new PrintButtonHandler();
        printB.addActionListener(pbHandler);


        exitB=new JButton("Exit");
        exitHandler= new ExitButtonHandler();
        exitB.addActionListener(exitHandler);


        setTitle("BOX");

        Container p=getContentPane();
        p.setLayout(new GridLayout(5,1));

        p.add(numL);
        p.add(numTF);
        p.add(resultL);
        p.add(resultTF);
        p.add(printB);
        p.add(exitB);

        setSize(600,600);
        setVisible(true);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
    }


        private class PrintButtonHandler implements ActionListener{
            public void actionPerformed(ActionEvent e){
               //Box1 p=new Box1();
                int num,height=5,width=5,numLL;
                  numLL=Integer.parseInt(numTF.getText());

                Font f = resultTF.getFont();
                resultTF.setFont(new Font(Font.MONOSPACED, f.getStyle(), f.getSize()));





            if(numLL==1){
                for(int i = 0; i < 5; i++) {
                 for(int j = 0; j < 5; j++) {
                resultTF.append(".");
                }
                resultTF.append("\n");
                }

            }else if(numLL==2){
                for(int i = 0; i < 5; i++) {
                 for(int j = 0; j < 5; j++) {
                resultTF.append("*");
                }
                resultTF.append("\n");
                }
            }else if(numLL>2){
                resultTF.append("NOT 1 OR 2:");

            }
            }
        }

        private class ExitButtonHandler implements ActionListener{
            public void actionPerformed(ActionEvent e){

                System.exit(0);

            }
        }

        public static void main(String[]args){
            Box p=new Box();
        }
}

Solution

Right now you are directing your boxes to System.out. So you need to direct them to your text component.

Also, you can't use JTextField for this because it is not multiline. Instead, you should use something like a JTextArea inside a JScrollPane.

resultTF = new JTextArea();
Font f = resultTF.getFont();
resultTF.setFont(new Font(Font.MONOSPACED, f.getStyle(), f.getSize()));

add(new JScrollPane(resultTF));

.
.
.

for(int i = 0; i < height; i++) {
    for(int j = 0; j < width; j++) {
        resultTF.append(".");
    }
    resultTF.append("\n");
}

If you don't want a scroll pane, you could also, for example, create the text area with specific rows and columns (new JTextArea(5, 5)), use a StringBuilder to create your box and use setText instead of append.

As a side note, you should be creating your GUI on the Swing event thread. In other words, your main should be wrapped in a call to invokeLater:

public static void main(String[] args) {
    SwingUtilities.invokeLater(new Runnable() {
        @Override
        public void run() {
            Box p = new Box();
        }
    });
}