Java 获取窗口的宽、高

创建一个新窗口，通过getSize()获取这个窗口的宽、高。

 import javax.swing.JFrame;

 public class WindowInTheMiddle extends JFrame {

     public static void main(String[] args) {
         WindowInTheMiddle window = new WindowInTheMiddle();
         window.launchFrame();

         // Width & Height
         System.out.println(window.getSize().getWidth());
         System.out.println(window.getSize().getHeight());
     }

     public void launchFrame() {
         this.setTitle("Hello World! I'm coming!");
         this.setSize(500, 500);
         this.setLocation(300, 300);
         this.setVisible(true);
     }
 }