【 格式化时间（SimpleDateFormat）用法】

String time = "2019-11-09";
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
Date dateTime = null;
try {
    dateTime = simpleDateFormat.parse(time);
} catch (ParseException e) {
    e.printStackTrace();
}

import java.text.SimpleDateFormat;
import java.util.Date;
 
public class Main{
    public static void main(String[] args){
        Date date = new Date();
        String strDateFormat = "yyyy-MM-dd HH:mm:ss";
        SimpleDateFormat sdf = new SimpleDateFormat(strDateFormat);
        System.out.println(sdf.format(date));
    }
}