java时间动态显示 两种方法

时间动态显示
1.方法一 用TimerTask
利用java.util.Timer和java.util.TimerTask来做动态更新，毕竟每次更新可以看作是计时1秒发生一次。
代码如下：
import java.awt.Dimension;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
/**
 * This class is a simple JFrame implementation to explain how to
 * display time dynamically on the JSwing-based interface.
 * @author Edison
 *
 */
public class TimeFrame extends JFrame
{
 /*
  * Variables
  */
 private JPanel timePanel;
 private JLabel timeLabel;
 private JLabel displayArea;
 private String DEFAULT_TIME_FORMAT = "HH:mm:ss";
 private String time;
 private int ONE_SECOND = 1000;
 
 public TimeFrame()
 {
  timePanel = new JPanel();
  timeLabel = new JLabel("CurrentTime: ");
  displayArea = new JLabel();
  
  configTimeArea();
  
  timePanel.add(timeLabel);
  timePanel.add(displayArea);
  this.add(timePanel);
  this.setDefaultCloseOperation(EXIT_ON_CLOSE);
  this.setSize(new Dimension(200,70));
  this.setLocationRelativeTo(null);
 }
 
 /**
  * This method creates a timer task to update the time per second
  */
 private void configTimeArea() {
  Timer tmr = new Timer();
  tmr.scheduleAtFixedRate(new JLabelTimerTask(),new Date(), ONE_SECOND);
 }
 
 /**
  * Timer task to update the time display area
  *
  */
 protected class JLabelTimerTask extends TimerTask{
  SimpleDateFormat dateFormatter = new SimpleDateFormat(DEFAULT_TIME_FORMAT);
  @Override
  public void run() {
   time = da