问如何使用时区偏移量将日期转换为时间？

EN

import java.util.Date;
import java.text.SimpleDateFormat;

class array05{
  public static void main(String[] args){
      SimpleDateFormat sf = new SimpleDateFormat("EEE, d MMM yyyy HH:mm:ss Z");
      System.out.println(sf.format(new Date()));
  }
}

Long gmtTime =1317951113613L; // 2.32pm NZDT
Long timezoneAlteredTime = 0L;

if (offset != 0L) {
    int multiplier = (offset*60)*(60*1000);
    timezoneAlteredTime = gmtTime + multiplier;
} else {
    timezoneAlteredTime = gmtTime;
}

Calendar calendar = new GregorianCalendar();
calendar.setTimeInMillis(timezoneAlteredTime);

DateFormat formatter = new SimpleDateFormat("dd MMM yyyy HH:mm:ss z");

formatter.setCalendar(calendar);
formatter.setTimeZone(TimeZone.getTimeZone(timeZone));

String newZealandTime = formatter.format(calendar.getTime());