温故知新 将Date和String类型相互转换

//Date转String 

public String DateToString(){

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

Date day=new Date();

String daybyday=sdf.fromat(day);

return daybyday;

}

//String转Date(DateTimeFormatte jdk 1.8以后(线程安全))

public Date StringToDate(){

DateTimeFormatter  dtf=TimeFormatter.ofPartten("yyyy-MM-dd HH:mm:ss");

LocalDate date=LocalDate.parse("2019-11-11 11:11:11",dtf);

return date;

}