package corejava; import java.awt.Dimension; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JTextArea; import javax.swing.JTree; public class FlowLayoutDemo extends JFrame { public FlowLayoutDemo() { setTitle("FlowLayout Example"); JPanel panel = new JPanel(); JTextArea area = new JTextArea("text area"); area.setPreferredSize(new Dimension(100, 100)); JButton button = new JButton("button"); panel.add(button); JTree tree = new JTree(); panel.add(tree); panel.add(area); add(panel); pack(); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setLocationRelativeTo(null); setVisible(true); } public static void main(String[] args) { new FlowLayoutDemo(); } }