Question

我想要一个以下面的方式工作的代码显示8-10个城市的时间，其中应自动处理DST。

For example : Melbourne observes DST, a API using which I can fetch the current time based on location without any hardcode done for DST calculation.

目前正在运行的代码基于硬编码值。它选择系统时间转换为GMT，然后根据位置添加/减去偏移量。

然后根据日期计算DST并适当添加。

但是我想使用一些API来删除硬编码的值，我试图使用下面的代码。

The below code giving time for IST/GMT, but when I put AEST/AEDT it doesnt give the correct time.


public class DateFormatter {

    public static String formatDateToString(Date date, String format,
            String timeZone) {
        // null check
        if (date == null) return null;
        // create SimpleDateFormat object with input format
        SimpleDateFormat sdf = new SimpleDateFormat(format);
        // default system timezone if passed null or empty
        if (timeZone == null || "".equalsIgnoreCase(timeZone.trim())) {
            timeZone = Calendar.getInstance().getTimeZone().getID();
        }
        // set timezone to SimpleDateFormat
        sdf.setTimeZone(TimeZone.getTimeZone(timeZone));
        // return Date in required format with timezone as String
        return sdf.format(date);
    }

    public static void main(String[] args) {
        //Test formatDateToString method
        Date date = new Date();
        System.out.println("Default Date:"+date.toString());
        System.out.println("System Date: "+formatDateToString(date, "dd MMM yyyy hh:mm:ss a", null));
        System.out.println("System Date in PST: "+formatDateToString(date, "dd MMM yyyy hh:mm:ss a", "PST"));
        System.out.println("System Date in IST: "+formatDateToString(date, "dd MMM yyyy hh:mm:ss a", "IST"));
        System.out.println("System Date in GMT: "+formatDateToString(date, "dd MMM yyyy hh:mm:ss a", "GMT"));
        System.out.println("System Date in CT: "+formatDateToString(date, "dd MMM yyyy hh:mm:ss a", "BDT"));
    }

}

Answer 1

import java.time.LocalTime;
import java.time.ZoneId;

public class Main {
  public static void main(String... args) {
        ZoneId zone2 = ZoneId.of("America/Santiago");
     LocalTime now2 = LocalTime.now(zone2);
    System.out.println(now2);
  }
}

Use the below link to know the timezones

http://joda-time.sourceforge.net/timezones.html

Answer 2

package com.java.test;

import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.TimeZone;

import javax.swing.text.ZoneView;

public class TestJavaCode {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
try
{
Calendar cal = GregorianCalendar.getInstance();
TimeZone tzone = cal.getTimeZone();
tzone.useDaylightTime();
System.out.println("Timezone:"+tzone.getDisplayName());


TimeZone tzone1 = TimeZone.getTimeZone("Canada/Central");
TimeZoneIDProvide.getTimeZoneID(TimeZoneID.US_EASTERN).getTimeZone();

Calendar cal1 = new GregorianCalendar(tzone1); 
cal1.setTimeInMillis(cal.getTimeInMillis());

System.out.println("Time in US Hour: "+cal1.get(Calendar.HOUR));
System.out.println("Time in US Min: "+cal1.get(Calendar.MINUTE));
System.out.println("Time in US Sec: "+cal1.get(Calendar.SECOND));



}
catch(Exception e)
{
System.out.println("Exception caught:"+e);
}

}

}

在JS / Java中任何城市的DST时间

2 个答案: