Java Code:
import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Shell;

public class FirstSWTClass {

  public static void main(String[] args) {
    Display display = new Display();
    Shell shell = new Shell(display);
    shell.setText("First SWT Application");
    shell.setSize(250, 250);
    Label label = new Label(shell, SWT.CENTER);
    label.setText("Greetings from SWT");
    label.setBounds(shell.getClientArea());
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch())
        display.sleep();
    }
    display.dispose();
  }
}