时间和时区

SimpleDateFormat 可以用来验证和转换带时区的时间数据，无论是Date或者是String。

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

public class test {
    public static void main(String[] args) throws ParseException {
        SimpleDateFormat dfNoTimezone = new SimpleDateFormat(
                "yyyy-MM-dd'T'HH:mm:ss");
        SimpleDateFormat dfTimezone = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ");
        Date now = new Date();
        // 将本地时间转换成带时区格式的时间
        System.out.println("local time     : " + dfNoTimezone.format(now));
        System.out.println("timezone time  : " + dfTimezone.format(now));
        
        //  将带时区格式的时间转成本地时间
        String chTime = "2018-01-08T09:30:32+0800";
        String utcTime = "2018-01-08T09:30:32+0000";
        String usTime = "2018-01-08T09:30:32-0700";
         System.out.println("East 8: " + dfNoTimezone.format(dfTimezone.parse(chTime)));
         System.out.println("UTC   : " + dfNoTimezone.format(dfTimezone.parse(utcTime)));
         System.out.println("West 7: " + dfNoTimezone.format(dfTimezone.parse(usTime)));
    }
}

运行结果：

local time     : 2018-01-07T17:00:35
timezone time  : 2018-01-07T17:00:35+0800
East 8: 2018-01-08T09:30:32
UTC   : 2018-01-08T17:30:32
West 7: 2018-01-09T00:30:32