在JFrame中使矩形居中

import javax.swing.JFrame;
import java.awt.Dimension;
import java.awt.Toolkit;

public class CenterRectangle {
    public static void main(String[] args) {
        // 创建JFrame对象
        JFrame frame = new JFrame("居中显示矩形");
        
        // 获取屏幕的宽度和高度
        Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
        int screenWidth = screenSize.width;
        int screenHeight = screenSize.height;
        
        // 创建矩形对象
        int rectangleWidth = 200;
        int rectangleHeight = 100;
        int x = (screenWidth - rectangleWidth) / 2;
        int y = (screenHeight - rectangleHeight) / 2;
        
        // 设置矩形的位置
        frame.setBounds(x, y, rectangleWidth, rectangleHeight);
        
        // 设置窗口关闭时的操作
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        
        // 显示窗口
        frame.setVisible(true);
    }
}