Java完成時光靜態顯示辦法匯總。本站提示廣大學習愛好者：（Java完成時光靜態顯示辦法匯總）文章只能為提供參考，不一定能成為您想要的結果。以下是Java完成時光靜態顯示辦法匯總正文
本文所述實例可以完成Java在界面上靜態的顯示時光。詳細完成辦法匯總以下：
1.辦法一 用TimerTask：
應用java.util.Timer和java.util.TimerTask來做靜態更新，究竟每次更新可以看做是計時1秒產生一次。
代碼以下：
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 = dateFormatter.format(Calendar.getInstance().getTime());
displayArea.setText(time);
}
}
public static void main(String arg[])
{
TimeFrame timeFrame=new TimeFrame();
timeFrame.setVisible(true);
}
}
繼續TimerTask來創立一個自界說的task，獲得以後時光，更新displayArea.
然後創立一個timer的實例，每1秒履行一次timertask。因為用schedule能夠會有時光誤差發生，所以直接挪用精度更高的scheduleAtFixedRate的。
2. 辦法二：應用線程：
這個就比擬簡略了。詳細代碼以下：
import java.awt.Dimension;
import java.text.SimpleDateFormat;
import java.util.Calendar;
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 DTimeFrame2 extends JFrame implements Runnable{
private JFrame frame;
private JPanel timePanel;
private JLabel timeLabel;
private JLabel displayArea;
private String DEFAULT_TIME_FORMAT = "HH:mm:ss";
private int ONE_SECOND = 1000;
public DTimeFrame2()
{
timePanel = new JPanel();
timeLabel = new JLabel("CurrentTime: ");
displayArea = new JLabel();
timePanel.add(timeLabel);
timePanel.add(displayArea);
this.add(timePanel);
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
this.setSize(new Dimension(200,70));
this.setLocationRelativeTo(null);
}
public void run()
{
while(true)
{
SimpleDateFormat dateFormatter = new SimpleDateFormat(DEFAULT_TIME_FORMAT);
displayArea.setText(dateFormatter.format(
Calendar.getInstance().getTime()));
try
{
Thread.sleep(ONE_SECOND);
}
catch(Exception e)
{
displayArea.setText("Error!!!");
}
}
}
public static void main(String arg[])
{
DTimeFrame2 df2=new DTimeFrame2();
df2.setVisible(true);
Thread thread1=new Thread(df2);
thread1.start();
}
}
比擬：
小我偏向於辦法一，由於Timer是可以被多個TimerTask共用，而發生一個線程，會增長多線程的保護龐雜度。
留意以下代碼：
jFrame.setDefaultCloseOperation(); // 給封閉按鈕增長特定行動 jFrame.setLocationRelativeTo(null); // 讓Frame一出來就在屏幕中央，而不是左上方。
將下面辦法一略微一修正，便可以顯示多國時光。代碼以下：
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;
import java.util.Timer;
import java.util.TimerTask;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
/**
* A simple world clock
* @author Edison
*
*/
public class WorldTimeFrame extends JFrame
{
/**
*
*/
private static final long serialVersionUID = 4782486524987801209L;
private String time;
private JPanel timePanel;
private TimeZone timeZone;
private JComboBox zoneBox;
private JLabel displayArea;
private int ONE_SECOND = 1000;
private String DEFAULT_FORMAT = "EEE d MMM, HH:mm:ss";
public WorldTimeFrame()
{
zoneBox = new JComboBox();
timePanel = new JPanel();
displayArea = new JLabel();
timeZone = TimeZone.getDefault();
zoneBox.setModel(new DefaultComboBoxModel(TimeZone.getAvailableIDs()));
zoneBox.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e) {
updateTimeZone(TimeZone.getTimeZone((String) zoneBox.getSelectedItem()));
}
});
configTimeArea();
timePanel.add(displayArea);
this.setLayout(new BorderLayout());
this.add(zoneBox, BorderLayout.NORTH);
this.add(timePanel, BorderLayout.CENTER);
this.setLocationRelativeTo(null);
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
this.setVisible(true);
pack();
}
/**
* 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
*
*/
public class JLabelTimerTask extends TimerTask{
SimpleDateFormat dateFormatter = new SimpleDateFormat(DEFAULT_FORMAT, Locale.ENGLISH);
@Override
public void run() {
dateFormatter.setTimeZone(timeZone);
time = dateFormatter.format(Calendar.getInstance().getTime());
displayArea.setText(time);
}
}
/**
* Update the timeZone
* @param newZone
*/
public void updateTimeZone(TimeZone newZone)
{
this.timeZone = newZone;
}
public static void main(String arg[])
{
new WorldTimeFrame();
}
}
原來須要在updateTimeZone(TimeZone newZone)中，更新displayArea的。然則斟酌到TimerTask履行的時光太短，才1秒鐘，以肉眼不雅察，根本上是和連忙更新沒差別。假如TimerTask履行時光長的話，這裡就要連忙從新居心的時光更新一下displayArea。
彌補：
①. pack() 用來主動盤算屏幕年夜小；
②. TimeZone.getAvailableIDs() 用來獲得一切的TimeZone。
