Java long 转成 String的实现

import java.text.SimpleDateFormat;
import java.util.Date;
 
public class TestTime {
 
  public static void main(String[] args) {
    String dateStr = fromLongToDate("yyyy-MM-dd HH:mm:ss", 1568020783663L);
    System.out.println(dateStr);
  }
 
  /**
   * Long类型时间->转换成日期->转成要求格式的String类型
   */
  public static String fromLongToDate(String format, Long time) {
    SimpleDateFormat sdf = new SimpleDateFormat(format);
    Date date = new Date(time);
    return sdf.format(date);
  } 
}