Why output is not appear when I run simulation? I need help thanks in advance.

[XmanOfStee]

package tempconv;

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;


public class TempConv extends JFrame
{

private JLabel CelL, FahrL;
private JTextField CelTF, FahrTF;
private CelsiusHandler cHandler;
private FahrenheitHandler fHandler;
        
private static final double FTOC = 5.0 / 9.0;
private static final double CTOF = 9.0 / 5.0;
private static final int OFFSET = 32;

private static final int WIDTH = 400;
private static final int HEIGHT = 100;

public void TempConv() //constructor
{
    //set labels
    CelL = new JLabel("Temp in Celsius: ", SwingConstants.RIGHT);
    FahrL = new JLabel("Temp in Fahrenheit: ", SwingConstants.RIGHT);
    
    //set text field
    cHandler = new CelsiusHandler();
    CelTF = new JTextField(10);
            
    //declare action listener object of its class 
    fHandler = new FahrenheitHandler();
    FahrTF = new JTextField(10);
                      
    
    //set title for window    
    setTitle("Temperature Conversion");
    
    //get the container
    Container pane = getContentPane();
    
    //set layout 
    pane.setLayout(new GridLayout(1, 4));        
    
    //Add info to window's content pane
    pane.add(CelL);
    pane.add(CelTF);
    pane.add(FahrL);    
    pane.add(FahrTF);                                       
    
    //register action listener
    CelTF.addActionListener(cHandler); 
    FahrTF.addActionListener(fHandler);   
    
    //set dimension
    setSize(WIDTH, HEIGHT);
    setVisible(true);                      
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    
}

private class CelsiusHandler implements ActionListener
{
    public void actionPerformed(ActionEvent e)
    {
        double celsius, fahrenheit;
        
        celsius = Double.parseDouble(CelTF.getText());
        
        fahrenheit = CTOF * celsius + OFFSET;
        
        FahrTF.setText(String.format("%.2f" + celsius));
    }
}

private class FahrenheitHandler implements ActionListener
{
    public void actionPerformed(ActionEvent e)
    {
        double celsius, fahrenheit;
        
        fahrenheit = Double.parseDouble(FahrTF.getText());
        
        celsius = FTOC * (fahrenheit -32);
        
        CelTF.setText(String.format("%.2f", +celsius));
    }
}

    public static void main(String[] args) 
    {
       TempConv outputTable = new TempConv();
    }
    
}

[r035198x]

You wrote public void TempConv() //constructor which is not correct. A constructor should have no return type at all. Instead you have void which makes it just a normal method. Change it to just

public TempConv()