import javax.swing.*;

public class TwoFrames {
    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> {
            JFrame f1 = new JFrame("1");
            f1.setBounds(100, 100, 300, 200);
            f1.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
            f1.setVisible(true);
            JFrame f2 = new JFrame("2");
            f2.setBounds(100, 400, 300, 200);
            f2.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
            f2.setVisible(true);
        });
    }
}