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

public class MainButton {

  public static void main(String[] args) {
    final Display display = new Display();
    Shell shell = new Shell(display);
    shell.setText("Radio Buttons");
    shell.pack();

    Button[] radios = new Button[3];

    radios[0] = new Button(shell, SWT.RADIO);
    radios[0].setSelection(true);
    radios[0].setText("Choice 1");
    radios[0].setBounds(10, 5, 75, 30);

    radios[1] = new Button(shell, SWT.RADIO);
    radios[1].setText("Choice 2");
    radios[1].setBounds(10, 30, 75, 30);

    radios[2] = new Button(shell, SWT.RADIO);
    radios[2].setText("Choice 3");
    radios[2].setBounds(10, 55, 75, 30);

    shell.open();
    shell.pack();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch())
        display.sleep();
    }
    display.dispose();
  }
}