一个基本的Java Swing程序

package cn.com.joycode.nimble.demo;


import javax.swing.*;
import java.awt.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.Set;

public class SwingBasicDemo {

    public static void setDefaultSize(int size) {

        Set<Object> keySet = UIManager.getLookAndFeelDefaults().keySet();
        Object[] keys = keySet.toArray(new Object[0]);

        for (Object key : keys) {

            if (key != null && key.toString().toLowerCase().contains("font")) {

                System.out.println(key);
                Font font = UIManager.getDefaults().getFont(key);
                if (font != null) {
                    font = font.deriveFont((float) size);
                    UIManager.put(key, font);
                }

            }

        }

    }

    public static void main(String[] args) {
        // 在事件派发线程中运行
        SwingUtilities.invokeLater(() -> {
            setDefaultSize(12);
            JFrame jfrm = new JFrame("编程小战");
            jfrm.setSize(800, 600);
            jfrm.setVisible(true);
            JLabel label = new JLabel("我去淄博吃烧烤!", SwingConstants.CENTER);
            label.setBorder(BorderFactory.createMatteBorder(10, 10, 10, 10, Color.BLUE));
            label.addMouseListener(new MouseAdapter() {
                @Override
                public void mouseClicked(MouseEvent e) {
                    JOptionPane.showMessageDialog(jfrm, "别闹！");

                }
            });
            jfrm.getContentPane().add(label);
            jfrm.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
            jfrm.addWindowListener(new WindowAdapter() {
                @Override
                public void windowClosing(WindowEvent e) {
                    System.exit(0);
                }
            });
        });
    }
}

运行后是这个样子：