java怎么获取时间

① java中如何获取时区

//我实现一个时钟窗口程序给你了，好让你更容易理解，希望对你有帮助。x0dx0aimport java.awt.*;x0dx0aimport java.awt.event.*;x0dx0aimport java.util.*;x0dx0ax0dx0a//世数粗拦界时钟凳扰x0dx0apublic class TimerTest {x0dx0apublic static void main(String[] args) {x0dx0anew TimerTestFrame("世薯胡界时钟");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"); // 创建时钟x0dx0aClockCanvas clk2 = new ClockCanvas("巴黎", "GMT+2");x0dx0aClockCanvas clk3 = new ClockCanvas("华盛顿", "GMT-4");x0dx0aClockCanvas clk4 = new ClockCanvas("洛衫矶", "GMT-7");x0dx0aClockCanvas clk5 = new ClockCanvas("伦敦", "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); // 设置框架宽高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//也可以通过TimeZone.setTimeZone(String n)函数改变时区，n为时区参数名。x0dx0acalendar = new GregorianCalendar(TimeZone.getTimeZone(tz));x0dx0at = new Thread(this);x0dx0at.start();x0dx0asetSize(125, 125); // 设置画布大小x0dx0asetBackground(Color.black);x0dx0a}x0dx0ax0dx0a// 重写父类的方法绘制时钟图形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()()获得当前时间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、获取当前的时间

Date date=new Date();//此时date为当前的时间

2、设置时间的格式

Date date=new Date();//此时date为当前的时间

System.out.println(date);

SimpleDateFormat dateFormat=new SimpleDateFormat(“YYYY-MM-dd”);//设置当前时间的格式，为年-月-日

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

SimpleDateFormat dateFormat_min=new SimpleDateFormat(“YYYY-MM-dd HH:mm:ss”);//设置当前时间的格式，为年-月-日 时-分-秒

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

(2)java怎么获取时间扩展阅读

java 获取当前微秒时间：

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(); // 纳秒

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

}

}

③ java 获取本机当前时间并对小时任意加减

代码如下：

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);//日期减1年

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

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

Datedt1=rightNow.getTime();

StringreStr=sdf.format(dt1);

System.out.println(reStr);

}

}

注：尘山竖在Calendar对象派大的add方法中，第二个参数为正数表示“加”，负数表示“减”。