设计滚动字演示线程状态及改变方法

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class WelcomeJFrame  extends JFrame{
public WelcomeJFrame(String texts[])         //texts指定移动字符串，数组长度决定窗口中的面板数
{
super("滚动字");
this.setBounds(300,240,400,300);
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
if(texts==null||texts.length==0)
this.getContentPane().add(new RollbyJPanel("Welcome!"));  //至少有一行字符串;
else
{
this.getContentPane().setLayout(new GridLayout(texts.length,1));
for(int i=0;i this.getContentPane().add(new RollbyJPanel(texts[i]));
}
this.setVisible(true);
}
public WelcomeJFrame() {this(null);}

private class RollbyJPanel extends JPanel implements ActionListener,Runnable
{
JTextField text_word,text_sleep,text_state;
JButton button_start,button_interrupt;
Thread thread;
int sleeptime;

RollbyJPanel(String text){
this.setLayout(new GridLayout(2,1));
text_word=new JTextField(String.format("%115s", text));
this.add(text_word);
JPanel panel_sub=new JPanel();
this.add(panel_sub);
panel_sub.add(new JLabel("sleep"));
this.sleeptime=(int)(Math.random()*100);
text_sleep=new JTextField(""+sleeptime,5);
panel_sub.add(text_sleep);
text_sleep.addActionListener(this);


button_start=new JButton("启动");
panel_sub.add(button_start);
button_start.addActionListener(this);
button_interrupt=new JButton("中断");
panel_sub.add(button_interrupt);
button_interrupt.addActionListener(this);


thread=new Thread(this);
button_interrupt.setEnabled(false);
panel_sub.add(new JLabel("state"));
text_state=new JTextField(""+thread.getState(),10);
text_state.setEnabled(false);
panel_sub.add(text_state);
}
public void run() {
while(true)
try
{
String str=text_word.getText();
text_word.setText(str.substring(1)+str.substring(0,1));
Thread.sleep(sleeptime);
}
catch(InterruptedException ex) {break;}

}
public void actionPerformed(ActionEvent ev)
{
if(ev.getSource()==button_start)
{
thread=new Thread(this);
thread.start();
text_state.setText(""+thread.getState());
button_start.setEnabled(false);
button_interrupt.setEnabled(true);
}

if(ev.getSource()==button_interrupt)
{
thread.interrupt();
text_state.setText(""+thread.getState());
button_start.setEnabled(true);
button_interrupt.setEnabled(false);
}
if(ev.getSource()==text_sleep)
try {
sleeptime=Integer.parseInt(text_sleep.getText());
}
catch(NumberFormatException nfex)
{
JOptionPane.showMessageDialog(this,"\""+text_sleep.getText()+"\"不能转换成整数，请重新输入！");
}
}
}
public static void main(String arg[])
{
String texts[]= {"Welcome","Hello","Rollyby"};
new WelcomeJFrame(texts);
}


}