ConvertTimeStampToDate-转化成日期

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

/**
 * Created on 2022/9/21.
 *
 * @author lichuanming
 */
public class ConvertTimeStampToDate {
    public static String stampToStringTime(Long lt) {
        String res;
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

        //将时间戳转换为时间
        Date date = new Date(lt);
        //将时间调整为yyyy-MM-dd HH:mm:ss时间样式
        res = simpleDateFormat.format(date);
        return res;
    }

    public static String stampToStringTime(Date date) {
        String res;
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");


        //将时间调整为yyyy-MM-dd HH:mm:ss时间样式
        res = simpleDateFormat.format(date);
        return res;
    }

    //将时间戳转换为时间
    public static Date stampToDateTime(Long lt) {
        String res;
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

        //将时间戳转换为时间
        Date date = new Date(lt);
        //将时间调整为yyyy-MM-dd HH:mm:ss时间样式
        res = simpleDateFormat.format(date);
        Date parse = null;
        try {
            parse = simpleDateFormat.parse(res);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return parse;
    }


    public static String getTime(int month) {
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Date date = new Date();
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        calendar.add(calendar.MONTH, month); //设置为前3月
        date = calendar.getTime();
        String defaultStartDate = simpleDateFormat.format(date); //格式化前month月的时间
        return defaultStartDate;
    }

    public static void main(String[] args) {
        System.out.println(getTime(0));
        System.out.println(getTime(-3));
    }

}