demo代码，直接运行：

package com.zhl.data;


import java.awt.*;  
import java.awt.event.*;  

import javax.swing.*; 
import javax.swing.JOptionPane;




public class window {
	public static void main(String[] args) throws IOException{
		window.JTextAreaDemo3();

		//Scanner sc = new Scanner(System.in);
		window.jta.append("请输入页码：\n");
		String inputs = (String) JOptionPane.showInputDialog(null,"请输入页码：\n","选择12306新闻的页面",JOptionPane.PLAIN_MESSAGE,null,null,"1"); 
                for(int i = 0; i <20; i++){
                         //输出内容
			window.jta.append("输出内容："+i+"\n");
                         //滚动条自动滚动到最下方
                        window.jta.setCaretPosition(window.jta.getText().length());
		}
		window.jta.append("\n\n\n\n\n------------------------------------------程序结束------------------------------------------\n\n\n\n\n");
		window.jta.setCaretPosition(window.jta.getText().length());
	}

	static JFrame jf;  
	static JPanel jpanel;  
	static JButton jb1, jb2, jb3;  
	static JTextArea jta = null;  
	static JScrollPane jscrollPane;  
  
    public static void JTextAreaDemo3() {  
  
        jf = new JFrame("12306新闻公告中的车次数据更新（只可在公司内网使用）");  
        Container contentPane = jf.getContentPane();  
        contentPane.setLayout(new BorderLayout());  
  
        jta = new JTextArea(10, 15);  
        jta.setTabSize(4);  
        jta.setFont(new Font("微软雅黑", Font.BOLD, 16));  
        jta.setLineWrap(true);// 激活自动换行功能  
        jta.setWrapStyleWord(true);// 激活断行不断字功能  
        jta.setBackground(Color.pink);  
  
        jscrollPane = new JScrollPane(jta);  
        jpanel = new JPanel();  
        jpanel.setLayout(new GridLayout(1, 3));  
  

  
        contentPane.add(jscrollPane, BorderLayout.CENTER);  
        contentPane.add(jpanel, BorderLayout.SOUTH);  
  
        jf.setSize(800, 800);  
        jf.setLocation(400, 200);  
        jf.setVisible(true);  
  
        jf.addWindowListener(new WindowAdapter() {  
            public void windowClosing(WindowEvent e) {  
                System.exit(0);  
            }  
        });  
    }  
  
    // 覆盖接口ActionListener的方法actionPerformed  
    public void actionPerformed(ActionEvent e) {  
        if (e.getSource() == jb1) {  
            jta.copy();  
        } else if (e.getSource() == jb2) {  
            jta.paste();  
        } else if (e.getSource() == jb3) {  
            jta.cut();  
        }  
    }  
      
 
}