Java时间日期转Cron表达式

老规矩话不多说直接上代码：
package com.hx.dxyw.service.impl;

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

/**

• java日期转cron表达式工具类
  */
  public class CronUtils {

  /**

  • 每年时间format格式
    */
    private static final String DATEFORMAT_YEAR = "ss mm HH dd MM ? yyyy";

    /**

  • 每天时间format格式
    /
    private static final String DATEFORMAT_EVERYDAY = "ss mm HH * ?";

    /**

  • 每周时间format格式
    /
    private static final String SUNDAY = "ss mm HH ? 1";
    private static final String MONDAY = "ss mm HH ? 2";
    private static final String TUESDAY = "ss mm HH ? 3";
    private static final String WEDNESDAY = "ss mm HH ? 4";
    private static final String THURSDAY = "ss mm HH ? 5";
    private static final String FRIDAY = "ss mm HH ? 6";
    private static final String SATURADY = "ss mm HH ? 7";

    public static String formatDateByPattern(Date date, String dateFormat) {
    SimpleDateFormat sdf = new SimpleDateFormat(dateFormat);
    String formatTimeStr = null;
    if (date != null) {

     formatTimeStr = sdf.format(date);
    

    }
    return formatTimeStr;
    }
    /**

  • 时间转换时间表达式
    */
    public static String getCron(Date date, String dateFormat) {
    return formatDateByPattern(date, dateFormat);
    }

    public static void main(String[] args)throws Exception{
    String cron = getCron(new Date(), SUNDAY);
    System.out.println("每周六执行"+cron);

    String cron1 = getCron(new Date(), DATEFORMAT_EVERYDAY);
    System.out.println("每天执行"+cron1);

    String cron2 = getCron(new Date(), DATEFORMAT_YEAR);
    System.out.println("执行一次"+cron2);

    }
    }