DateタイプとLongタイプの相互変換

import java.text.SimpleDateFormat;

import java.util.Date;



public class T {

    public static void main(String[] args) throws Exception {

        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

        // 1.Date Long 

        // parse() '2011-09-20 12:30:45' Date ,getTime() Date Long 

        long timeStart = sdf.parse("2011-09-20 12:30:45").getTime();

        System.out.println(timeStart);

        // 2.Long Date 

        Date date = new Date(timeStart);

        System.out.println(sdf.format(date));

    }

}