Java输出系统当前的日期(年月日时分秒毫秒)

package test.remote.tools.combine;

import java.text.simpledateformat;
import java.util.calendar;
import java.util.date;
import java.util.gregoriancalendar;

public class testoutdate
{
public static void main(string[] args)
{
//method 1
calendar nowtime = new gregoriancalendar();
string strdatetime="["+string.format("%04d", nowtime.get(calendar.year))+"/"+
string.format("%02d", nowtime.get(calendar.month))+"/" +
string.format("%02d", nowtime.get(calendar.date))+" " +
string.format("%02d", nowtime.get(calendar.hour))+":" +
string.format("%02d", nowtime.get(calendar.minute))+":" +
string.format("%02d", nowtime.get(calendar.second))+"." +
string.format("%03d", nowtime.get(calendar.millisecond))+"]";
system.out.println(strdatetime);

//method 2
string msg="";
date date = new date();
simpledateformat sdf = new simpledateformat("yyyy/mm/dd hh:mm:ss.sss");
msg+="["+sdf.format(date)+"]";

system.out.println(msg);
}
}