public class JscrollPaneDemo extends JFrame{
 private JPanel contentPane; 
 private JScrollPane scrollPane;
 private JTextArea textArea;
 public JscrollPaneDemo(){
 contentPane=new JPanel();
 contentPane.setBorder(new EmptyBorder(5,5,5,5));
 contentPane.setLayout(new BorderLayout(0,0));
 this.setContentPane(contentPane);
 scrollPane=new JScrollPane();
 contentPane.add(scrollPane,BorderLayout.CENTER);
 textArea=new JTextArea();
 //scrollPane.add(textArea); 
 scrollPane.setViewportView(textArea);
 this.setTitle("滚动面板使用");
 this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 this.setBounds(100, 100, 250, 200);
 this.setVisible(true);
 }
 public static void main(String []args){
 @SuppressWarnings("unused")
  JscrollPaneDemo example=new JscrollPaneDemo(); 
 }
}