Example

public static void main( String[] args ) {
JFrame frame = new JFrame();
JTextField textField = new JTextField();
textField.setBounds( 122, 26, 277, 27 );
frame.getContentPane().add( textField );
frame.setVisible( true );
}

Solução
Utilize o gerenciador de layout do Java porque ele ajustará o GUI automaticamente.

public static void main( String[] args ) {
JFrame frame = new JFrame();
JTextField textField = new JTextField();
frame.getContentPane().setLayout( new GridLayout() );
frame.getContentPane().add( textField );
frame.setVisible( true );
}