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

public class CalendarTest extends JPanel {
	public CalendarTest() {
		setPreferredSize(new Dimension(250, 100));
	}

	@Override
	public void paintComponent(Graphics g) {
		super.paintComponent(g);
		Calendar now = Calendar.getInstance();
		int day  = now.get(Calendar.DAY_OF_WEEK);
		int hour = now.get(Calendar.HOUR_OF_DAY);
		int min  = now.get(Calendar.MINUTE);
		if (day == Calendar.SUNDAY) {
			g.setColor(Color.RED);
			g.drawString("今日は日曜日です。", 30, 25);
		}
		if (hour < 12) {
			g.drawString("おはようございます。", 30, 75);
		} else if (hour < 18) {
			g.drawString("こんにちは。", 30, 75);
		} else {
			g.drawString("こんばんは。", 30, 75);
		}
		g.drawString("ただいま " + hour + "時 " + min + "分です。", 30, 50);
		// g.drawString(String.format("ただいま %d時 %d分です。", hour, min), 30, 50);
	}

	public static void main(String[] args) {
		SwingUtilities.invokeLater(() -> {
			JFrame frame = new JFrame("");
			frame.add(new CalendarTest());
			frame.pack();
			frame.setVisible(true);
			frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		});
	}
}