import javax.swing.*; class Main { { f.add(b); f.setSize(100,100); f.setVisible(true); } }
Standard input is empty
Standard output is empty
Exception in thread "main" java.awt.HeadlessException: No X11 DISPLAY variable was set, but this program performed an operation which requires it. at java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:207) at java.awt.Window.<init>(Window.java:535) at java.awt.Frame.<init>(Frame.java:420) at javax.swing.JFrame.<init>(JFrame.java:224) at Main.main(Main.java:6)