GridLayout.setColumns(int cols) has the following syntax.
public void setColumns(int cols)
In the following code shows how to use GridLayout.setColumns(int cols) method.
//www.ja v a 2 s . c o m import java.awt.GridLayout; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; public class Main extends JPanel { public Main(){ JButton button = new JButton("w w w.j a v a 2 s . c o m"); add(button); add(new JButton("w w w.j a v a 2 s . com" )); add(new JButton("w w w.java2s.com" )); add(new JButton("www.j ava 2 s . c o m" )); GridLayout gridLayout = new GridLayout(); gridLayout.setColumns(2); gridLayout.setRows(2); setLayout(gridLayout); } public static void main(String[] args) { JFrame frame = new JFrame(); frame.getContentPane().add(new Main()); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setSize(200,200); frame.setVisible(true); } }