java怎麼獲取時間

① java中如何獲取時區

//我實現一個時鍾窗口程序給你了，好讓你更容易理解，希望對你有幫助。x0dx0aimport java.awt.*;x0dx0aimport java.awt.event.*;x0dx0aimport java.util.*;x0dx0ax0dx0a//世數粗攔界時鍾凳擾x0dx0apublic class TimerTest {x0dx0apublic static void main(String[] args) {x0dx0anew TimerTestFrame("世薯胡界時鍾");x0dx0a}x0dx0a}x0dx0ax0dx0aclass TimerTestFrame extends Frame {x0dx0a/**x0dx0a* x0dx0a*/x0dx0aprivate static final long serialVersionUID = 1L;x0dx0ax0dx0apublic TimerTestFrame(String s) {x0dx0asuper(s);x0dx0aaddWindowListener(new WindowAdapter() {x0dx0apublic void windowClosing(WindowEvent e) {x0dx0adispose();x0dx0aSystem.exit(0);x0dx0a}x0dx0a});x0dx0asetLayout(new GridLayout(2, 6));x0dx0ax0dx0aClockCanvas clk1 = new ClockCanvas("北京", "GMT+8"); // 創建時鍾x0dx0aClockCanvas clk2 = new ClockCanvas("巴黎", "GMT+2");x0dx0aClockCanvas clk3 = new ClockCanvas("華盛頓", "GMT-4");x0dx0aClockCanvas clk4 = new ClockCanvas("洛衫磯", "GMT-7");x0dx0aClockCanvas clk5 = new ClockCanvas("倫敦", "GMT+1");x0dx0aClockCanvas clk6 = new ClockCanvas("芝加哥", "GMT-5");x0dx0aadd(clk1);x0dx0aadd(clk2);x0dx0aadd(clk3);x0dx0aadd(clk4);x0dx0aadd(clk5);x0dx0aadd(clk6);x0dx0asetSize(500, 350); // 設置框架寬高x0dx0asetVisible(true);x0dx0a}x0dx0a}x0dx0ax0dx0aclass ClockCanvas extends Canvas implements Runnable {x0dx0a/**x0dx0a* x0dx0a*/x0dx0aprivate static final long serialVersionUID = 1L;x0dx0ax0dx0aprivate int seconds = 0;x0dx0ax0dx0aprivate String city;x0dx0ax0dx0aprivate GregorianCalendar calendar;x0dx0ax0dx0aThread t;x0dx0ax0dx0apublic ClockCanvas(String c, String tz) {x0dx0acity = c;x0dx0a//也可以通過TimeZone.setTimeZone(String n)函數改變時區，n為時區參數名。x0dx0acalendar = new GregorianCalendar(TimeZone.getTimeZone(tz));x0dx0at = new Thread(this);x0dx0at.start();x0dx0asetSize(125, 125); // 設置畫布大小x0dx0asetBackground(Color.black);x0dx0a}x0dx0ax0dx0a// 重寫父類的方法繪制時鍾圖形x0dx0apublic void paint(Graphics g) {x0dx0aGraphics2Dg2d = (Graphics2D) g;x0dx0aBasicStroke bstroke = new BasicStroke(2.0f);x0dx0ag2d.setStroke(bstroke);x0dx0ag2d.setColor(Color.green);x0dx0ag2d.drawOval(0, 0, 100, 100);x0dx0abstroke = new BasicStroke(5.0f);x0dx0ag2d.setStroke(bstroke);x0dx0ag2d.drawLine(50, 0, 50, 5);x0dx0ag2d.drawLine(0, 50, 5, 50);x0dx0ag2d.drawLine(50, 95, 50, 98);x0dx0ag2d.drawLine(95, 50, 98, 50);x0dx0adouble hourAngle = 2 * Math.PI * (seconds - 3 * 60 * 60)x0dx0a/ (12 * 60 * 60);x0dx0adouble minuteAngle = 2 * Math.PI * (seconds - 15 * 60) / (60 * 60);x0dx0adouble secondAngle = 2 * Math.PI * (seconds - 15) / (60);x0dx0abstroke = new BasicStroke(5.0f);x0dx0ag2d.setStroke(bstroke);x0dx0ag2d.drawLine(50, 50, 50 + (int) (30 * Math.cos(hourAngle)),x0dx0a50 + (int) (30 * Math.sin(hourAngle)));x0dx0abstroke = new BasicStroke(3.0f);x0dx0ag2d.setStroke(bstroke);x0dx0ag2d.drawLine(50, 50, 50 + (int) (40 * Math.cos(minuteAngle)),x0dx0a50 + (int) (40 * Math.sin(minuteAngle)));x0dx0abstroke = new BasicStroke(1.0f);x0dx0ag2d.setStroke(bstroke);x0dx0ag2d.drawLine(50, 50, 50 + (int) (45 * Math.cos(secondAngle)),x0dx0a50 + (int) (45 * Math.sin(secondAngle)));x0dx0ag2d.setColor(Color.red);x0dx0ag2d.drawString(city, 35, 115);x0dx0a}x0dx0ax0dx0apublic void timeElapsed() {x0dx0a//new Date()()獲得當前時間x0dx0aSystem.out.println(new Date()());x0dx0acalendar.setTime(new Date()());x0dx0aseconds = calendar.get(Calendar.HOUR) * 60 * 60x0dx0a+ calendar.get(Calendar.MINUTE) * 60x0dx0a+ calendar.get(Calendar.SECOND);x0dx0a}x0dx0ax0dx0apublic void run() {x0dx0atry {x0dx0awhile (true) {x0dx0aThread.sleep(300);x0dx0atimeElapsed();x0dx0arepaint();x0dx0a}x0dx0a} catch (InterruptedException e) {x0dx0a}x0dx0a}x0dx0a}

② java如何得到年月日。

1、獲取當前的時間

Date date=new Date();//此時date為當前的時間

2、設置時間的格式

Date date=new Date();//此時date為當前的時間

System.out.println(date);

SimpleDateFormat dateFormat=new SimpleDateFormat(「YYYY-MM-dd」);//設置當前時間的格式，為年-月-日

System.out.println(dateFormat.format(date));

SimpleDateFormat dateFormat_min=new SimpleDateFormat(「YYYY-MM-dd HH:mm:ss」);//設置當前時間的格式，為年-月-日 時-分-秒

System.out.println(dateFormat_min.format(date));

(2)java怎麼獲取時間擴展閱讀

java 獲取當前微秒時間：

package com.ffcs.itm;

public class DataSecUtils {

public static void main(String[] args) {

System.out.println(System.currentTimeMillis()); // 毫秒

System.out.println(getmicTime());

System.out.println(System.currentTimeMillis()); // 毫秒

System.out.println(getmicTime());

}

/**

* @return返回微秒

*/

public static Long getmicTime() {

Long cutime = System.currentTimeMillis() * 1000; // 微秒

Long nanoTime = System.nanoTime(); // 納秒

return cutime + (nanoTime - nanoTime / 1000000 * 1000000) / 1000;

}

}

③ java 獲取本機當前時間並對小時任意加減

代碼如下：

importjava.text.SimpleDateFormat;

importjava.util.Calendar;

importjava.util.Date;

publicclassDateTestUtil{

publicstaticvoidmain(String[]args)throwsException{

SimpleDateFormatsdf=newSimpleDateFormat("yyyyMMdd");

Stringstr="20110823";

Datedt=sdf.parse(str);

CalendarrightNow=Calendar.getInstance();

rightNow.setTime(dt);

rightNow.add(Calendar.YEAR,-1);//日期減1年

rightNow.add(Calendar.MONTH,3);//日期加3個月

rightNow.add(Calendar.DAY_OF_YEAR,10);//日期加10天

Datedt1=rightNow.getTime();

StringreStr=sdf.format(dt1);

System.out.println(reStr);

}

}

註：塵山豎在Calendar對象派大的add方法中，第二個參數為正數表示「加」，負數表示「減」。