在Android中以格式转换GMT到IST时区

Question

在我的应用程序中，我以GMT格式（YYYY-MM-DD hr-min-sec GMT）从服务器获取时间值，但我想以IST格式显示（Aug- DD-YYYY hr-min-sec IST）。请帮助我如何以编程方式...

在此先感谢！

Answer 1

我们将使用SimpleDateFormat类以特定格式格式化日期，我们将设置它的时区以在特定时区打印日期。

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

public class DateFormatter { 

    /** 
    * Utility function to convert java Date to TimeZone format 
    * @param date 
    * @param format 
    * @param timeZone 
    * @return 
    */ 
    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")); 
    } 

} 

这里是程序的输出：

Default Date:Wed Nov 14 21:37:01 PST 2012 
System Date: 14 Nov 2012 09:37:01 PM 
System Date in PST: 14 Nov 2012 09:37:01 PM 
System Date in IST: 15 Nov 2012 11:07:01 AM 
System Date in GMT: 15 Nov 2012 05:37:01 AM