import java.text.ParseException;

import java.text.SimpleDateFormat;

import java.util.Calendar;

import java.util.Date;

import java.util.TimeZone;

public class TimeUtil {

    private final static String MINTUE = "yyyyMMddHHmm";

    public static String getUTCTime(String dateStr) throws ParseException

    {

        SimpleDateFormat sdf = new SimpleDateFormat(MINTUE);

        Date date = sdf.parse(dateStr);

        Calendar calendar = Calendar.getInstance();

        calendar.setTime(date);

        //方法1：直接计算相差的时间得到UTC时间

        long unixTimeGMT = calendar.getTimeInMillis() - TimeZone.getDefault().getRawOffset();

        System.out.println(unixTimeGMT);

        //方法2：通过获得时区偏移量和夏时令偏移量，再计算UTC时间

        int timeZone = calendar.get(Calendar.ZONE_OFFSET);

        System.out.println(timeZone);

        int dst = calendar.get(Calendar.DST_OFFSET);

        System.out.println(dst);

        calendar.add(Calendar.MILLISECOND, -(timeZone + dst));

        System.out.println(calendar.getTimeInMillis());

        return "";

    }

}