在线等待，马上给分！java中如何获取系统时间？

Question

Date now=new Date();
now.getHours();
now.getMinutes();
now.getSeconds();

Answer 1

这是一个计算时间差的程序，改动以下就可以了！！！ 好运~~~~
package ppmsys.pre.client;import java.util.*;
import java.text.*;
/**
SimpleDateFormat sdf=new SimpleDateFormat("yyyyMMdd");
String str="20011230";
Date dt=sdf.parse(str,new ParsePosition(0));
Calendar rightNow = Calendar.getInstance();
rightNow.setTime(dt);
rightNow.add(Calendar.DATE,2);//你要加减的日期
Date dt1=rightNow.getTime();
String reStr=sdf.format(dt1,"",new FieldPosition(0));
System.out.println(reStr);
 *
 */public class ThreeDaysAgo
{
public static void main(String args[])
{
GregorianCalendar calendar = new GregorianCalendar();
Date date = calendar.getTime ();
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); System.out.println ("Today: "+df.format (date)); calendar.set (Calendar.DATE,
calendar.get (Calendar.DATE)-3);
date = calendar.getTime ();
System.out.println ("Three days ago: "+df.format (date));                 String[] ids = TimeZone.getAvailableIDs(-8 * 60 * 60 * 1000);
 // if no ids were returned, something is wrong. get out.
 if (ids.length == 0)
     System.exit(0);  // begin output
 System.out.println("Current Time"); // create a Pacific Standard Time time zone
 SimpleTimeZone pdt = new SimpleTimeZone(-8 * 60 * 60 * 1000, ids[0]); // set up rules for daylight savings time
 pdt.setStartRule(Calendar.APRIL, 1, Calendar.SUNDAY, 2 * 60 * 60 * 1000);
 pdt.setEndRule(Calendar.OCTOBER, -1, Calendar.SUNDAY, 2 * 60 * 60 * 1000); // create a GregorianCalendar with the Pacific Daylight time zone
 // and the current date and time
 Calendar calendar1 = new GregorianCalendar(pdt);
 Date trialTime = new Date();
 calendar1.setTime(trialTime); // print out a bunch of interesting things
 System.out.println("ERA: " + calendar1.get(Calendar.ERA));
 System.out.println("YEAR: " + calendar1.get(Calendar.YEAR));
 System.out.println("MONTH: " + calendar1.get(Calendar.MONTH));
 System.out.println("WEEK_OF_YEAR: " + calendar1.get(Calendar.WEEK_OF_YEAR));
 System.out.println("WEEK_OF_MONTH: " + calendar1.get(Calendar.WEEK_OF_MONTH));
 System.out.println("DATE: " + calendar1.get(Calendar.DATE));
 System.out.println("DAY_OF_MONTH: " + calendar1.get(Calendar.DAY_OF_MONTH));
 System.out.println("DAY_OF_YEAR: " + calendar1.get(Calendar.DAY_OF_YEAR));
 System.out.println("DAY_OF_WEEK: " + calendar1.get(Calendar.DAY_OF_WEEK));
 System.out.println("DAY_OF_WEEK_IN_MONTH: "+ calendar1.get(Calendar.DAY_OF_WEEK_IN_MONTH));
 System.out.println("AM_PM: " + calendar1.get(Calendar.AM_PM));
 System.out.println("HOUR: " + calendar1.get(Calendar.HOUR));
 System.out.println("HOUR_OF_DAY: " + calendar1.get(Calendar.HOUR_OF_DAY));
 System.out.println("MINUTE: " + calendar1.get(Calendar.MINUTE));
 System.out.println("SECOND: " + calendar1.get(Calendar.SECOND));
 System.out.println("MILLISECOND: " + calendar1.get(Calendar.MILLISECOND));
 System.out.println("ZONE_OFFSET: "
                    + (calendar1.get(Calendar.ZONE_OFFSET)/(60*60*1000)));
 System.out.println("DST_OFFSET: "
                    + (calendar1.get(Calendar.DST_OFFSET)/(60*60*1000))); System.out.println("Current Time, with hour reset to 3");
 calendar1.clear(Calendar.HOUR_OF_DAY); // so doesn't override
 calendar1.set(Calendar.HOUR, 3);
 System.out.println("ERA: " + calendar1.get(Calendar.ERA));
 System.out.println("YEAR: " + calendar1.get(Calendar.YEAR));
 System.out.println("MONTH: " + calendar1.get(Calendar.MONTH));
 System.out.println("WEEK_OF_YEAR: " + calendar1.get(Calendar.WEEK_OF_YEAR));
 System.out.println("WEEK_OF_MONTH: " + calendar1.get(Calendar.WEEK_OF_MONTH));
 System.out.println("DATE: " + calendar1.get(Calendar.DATE));
 System.out.println("DAY_OF_MONTH: " + calendar1.get(Calendar.DAY_OF_MONTH));
 System.out.println("DAY_OF_YEAR: " + calendar1.get(Calendar.DAY_OF_YEAR));
 System.out.println("DAY_OF_WEEK: " + calendar1.get(Calendar.DAY_OF_WEEK));
 System.out.println("DAY_OF_WEEK_IN_MONTH: "
                    + calendar1.get(Calendar.DAY_OF_WEEK_IN_MONTH));
 System.out.println("AM_PM: " + calendar1.get(Calendar.AM_PM));
 System.out.println("HOUR: " + calendar1.get(Calendar.HOUR));
 System.out.println("HOUR_OF_DAY: " + calendar1.get(Calendar.HOUR_OF_DAY));
 System.out.println("MINUTE: " + calendar1.get(Calendar.MINUTE));
 System.out.println("SECOND: " + calendar1.get(Calendar.SECOND));
 System.out.println("MILLISECOND: " + calendar1.get(Calendar.MILLISECOND));
 System.out.println("ZONE_OFFSET: "
        + (calendar1.get(Calendar.ZONE_OFFSET)/(60*60*1000))); // in hours
 System.out.println("DST_OFFSET: "
        + (calendar1.get(Calendar.DST_OFFSET)/(60*60*1000))); // in hours
}
}

Answer 2

给你一个现成的类
package com.hoten.util;
import java.util.*;public class getDate {  public getDate() {
  }  public static String get1yyyymmddhhmmssDate(){
    Calendar date = java.util.Calendar.getInstance();    String reStr = String.valueOf(date.get(Calendar.YEAR)) + addZero(date.get(Calendar.MONTH) + 1) +
                    addZero(date.get(Calendar.DATE)) + addZero(date.get(Calendar.HOUR)) +
                    addZero(date.get(Calendar.MINUTE)) + addZero(date.get(Calendar.SECOND));
    return reStr;
  }  public static String get14Date(){
    Calendar date = java.util.Calendar.getInstance();
    int intMSecond =  date.get(Calendar.MILLISECOND);
    String strMSecond;
    if (intMSecond < 10)
      strMSecond = "00" + String.valueOf(intMSecond);
    else if (intMSecond < 100)
      strMSecond = "0" + String.valueOf(intMSecond);
    else
      strMSecond = String.valueOf(intMSecond);    String reStr = String.valueOf(date.get(Calendar.YEAR)).substring(3) + addZero(date.get(Calendar.MONTH) + 1) +
                    addZero(date.get(Calendar.DATE)) + addZero(date.get(Calendar.HOUR)) +
                    addZero(date.get(Calendar.MINUTE)) + addZero(date.get(Calendar.SECOND))+strMSecond;
    return reStr;
  }  private static String addZero(int int1){
  String reStr;
    if (int1 < 10)
      reStr = "0" + String.valueOf(int1);
    else
      reStr = String.valueOf(int1);
    return reStr;
  }
}

Answer 3

Calendar tt = Calendar.getInstance();
Date time = new Date();
time = tt.getTime();
time就是所要的时间

Answer 4

/**
 * 获取当前时间, 格式为: yyyy-mm-dd hh-mm-ss
 * @return String 当前时间
 */
public static String getNow()
{
return DateFormat.getDateTimeInstance(2, 2, getLocale()).format( new java.util.Date() );
} /**
 * 获取当前时间, 格式为: yyyy年mm月dd日 上午/下午hh时mm分ss秒
 * @return String 当前时间
 */
public static String getNowLong()
{
return DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.LONG, getLocale()).format( new java.util.Date() );
} /**
 * 获取当前时间(精确到毫秒), 格式为: yyyy-mm-dd hh:mm:ss.nnn
 * @return String 当前时间
 */
public static String getNowNano()
{
return new java.sql.Timestamp( System.currentTimeMillis() ).toString();
} /**
 * 获取指定的Locale对象
 * @return Locale 返回Locale对象
 */
private static Locale getLocale()
{
return Locale.CHINESE;
}