如何在Swing Layout中管理组件？

Question

以下代码来自我的学校作业。做了一个mainFrame类的对象，它假设显示一些文本字段和按钮。 问题是我创建的所有内容都属于同一行，不幸的是，我无法使用java FX。如何让它们落在不同的行？谢谢

    public class TempConverter extends MainFrame {
            public TempConverter() {
            super("Simple Temperature Converter Application", 350,160);
              //  add(new ConverterPanel());
            }
            static public void main(String[] args) {
                TempConverter tcApp = new TempConverter();
                tcApp.display();
            }
   }

// == mainFrame

     /**
      * Created by Shirin on 2/4/17.
      */
    import javax.swing.*;
    import java.awt.*;

    public class MainFrame extends JFrame{

         JPanel panel = new JPanel();


        private JLabel lab;
        JButton toCelsius = new JButton("To Celsius");
        JButton toFahrenheit = new JButton("To Fahrenheit ");
        TextField fahrenheitText = new TextField(), celsiusText = new TextField();
        TextField toCelsiusText = new TextField(),toFahrenheitText = new TextField();


            public MainFrame(String title, int width, int height) {
                super(title);
                this.setFrame(width, height);
            }


            public void display() {

                setVisible(true);
            }

            private void setFrame(int width, int height) {
                setSize(width, height);
                setLocationRelativeTo(null);
                setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);


                this.addComponents();


            }
            public void addComponents(){
                fahrenheitText.setSize(42,42);
                fahrenheitText.setLocation(0,0);


                toCelsius.setSize(42,42);

                toCelsiusText.setLocation(2,2);
                toCelsiusText.isEnabled();

                celsiusText.setSize(200,100);
                celsiusText.isEnabled();
                celsiusText.setLocation(6,6);
                toFahrenheit.setSize(42,42);

                panel.add(fahrenheitText);
                panel.add(toCelsius);
                panel.add(toCelsiusText);
                panel.add(celsiusText);
                panel.add(toFahrenheit);

                this.add(panel);

            }

        }