我假设了你的已知时间类型为Calendar,如果不是你也可以自己改成Date类型,代码如下:
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.TimeZone;
public class Test {
public static void main(String[] args) {
//假如这个是你已知的时间类型
Calendar cal = Calendar.getInstance();
cal.getTimeInMillis();
//北京时区GMT+8
Calendar beijingcal = Calendar.getInstance();
beijingcal.clear();
beijingcal.setTimeZone(TimeZone.getTimeZone("GMT+8"));
beijingcal.setTimeInMillis(cal.getTimeInMillis());
DateFormat fmt = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String beijingFormatStr = fmt.format(beijingcal.getTime());
System.out.println(beijingFormatStr);
}
}