Java的日期工具类，根据月份获取

Java的日期工具类，根据月份获取

package com.ls.testmonth;

import java.sql.Date;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
 * 月份的工具类
 */
public class MonthUtils {
    /**
     * 根据当月获取上个月的第一天和最后一天
     */
    public static  Map<String, String> getLastMonth(String month) {
        Map<String, String>  map = new HashMap<String, String>();
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
        //创建一个日历对象
        Calendar calendar2 = Calendar.getInstance();
        Calendar cale = Calendar.getInstance();
        try {
            calendar2.setTime(new SimpleDateFormat("yyyy-MM").parse(month));
            cale.setTime(new SimpleDateFormat("yyyy-MM").parse(month));
        } catch (ParseException e) {
            calendar2.setTime(new java.util.Date());
            cale.setTime(new java.util.Date());
        }
        calendar2.add(Calendar.MONTH, -1);
        calendar2.set(Calendar.DAY_OF_MONTH, 1);
        String startDate = format.format(calendar2.getTime());
        cale.set(Calendar.DAY_OF_MONTH, 0);//设置为1号,当前日期既为本月第一天
        String endDate = format.format(cale.getTime());
        map.put("startDate", startDate);
        map.put("endDate", endDate);
        return map;

    }
    /**
     * 根据月的开始和和结束，遍历每个月的第一天和最后一天
     * @param startMonth
     * @param endMonth
     * @return
     */
    public static List<String> getMonth(String startMonth, String endMonth) {
        java.util.Date d1 = null;//定义起始日期
        java.util.Date d2 = null;
        java.util.Date d3 =null;
        Calendar cal = Calendar.getInstance();
        try {
            d1 = new SimpleDateFormat("yyyy-MM").parse(startMonth);
            d2 =   new SimpleDateFormat("yyyy-MM").parse(endMonth);
            cal.setTime(d2);
            cal.add(Calendar.MONTH, +1);
            d3 = cal.getTime();
        } catch (ParseException e) {
            e.printStackTrace();
        }//定义起始日期

        //定义结束日期
        Calendar dd = Calendar.getInstance();//定义日期实例

        dd.setTime(d1);//设置日期起始时间
        List<String> list = new ArrayList<String>();
        while(dd.getTime().before(d3)){//判断是否到结束日期
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM");
            String str = sdf.format(dd.getTime());
            list.add(str);
            dd.add(Calendar.MONTH, 1);//进行当前日期月份加1

        }
        return list;
    }
   
    /**
     * 根据月获取当前月的第一天和最后一天
     * @param month
     * @return
     */
    public static Map<String, Object> getCurrentMonth(String month) {
    	Map<String, Object> map= new HashMap<>();
		  //将时间进行格式化
        //创建一个日历对象
        Calendar calendar = Calendar.getInstance();
        try {
            calendar.setTime(new SimpleDateFormat("yyyy-MM").parse(month));
        } catch (ParseException e) {
            calendar.setTime(new java.util.Date());
        }
        int maxDay = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
        calendar.set(Calendar.DAY_OF_MONTH, 1);
        Date startDate = new Date(calendar.getTime().getTime());
        calendar.set(Calendar.DAY_OF_MONTH, maxDay);
        Date endDate = new Date(calendar.getTime().getTime());
        map.put("startDate", startDate);
        map.put("endDate", endDate);
        return map;
	
}

}

获取每天指几点的毫秒值

//获取当前时间
long time = System.currentTimeMillis();
 //获取每天13点的毫秒值
        Calendar c = Calendar.getInstance();
        c.set(Calendar.HOUR_OF_DAY, 13);
        c.set(Calendar.MINUTE, 0);
        c.set(Calendar.SECOND, 0);
        c.set(Calendar.MILLISECOND, 0);
        long startTime = c.getTimeInMillis();