【时间工具】整理下java时间换算专题

首先总结了一下日期转换基础，最常用的两个工具类Date与calender，转换方法如下：

package com.zzt.spider;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
/**
 * 时间工具总结
 * @author ZX
 * @date 2018年4月20日
 *
 */
public class TestTime {
	public static void main(String[] args) {
		//date 与calandar
		try{
			//首先是Date的格式化与反格式化。yyyy-MM-dd HH:mm:ss 分别对应 年-月-日 时：分：秒
			//"HH:mm:ss"是24小时制的，"hh:mm:ss"是12小时制。
			SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
			//日期的格式化转换
			Date now = new Date();
			String format = sdf.format(now);
			System.out.println(format);//结果：2018-05-02 16:51:13
			//
			String time = "2018-05-02 16:51:13";
			Date parse = sdf.parse(time);
			System.out.println(format);//

			//获取时间戳
			Date date = new Date();
			long time1 = date.getTime();//获取时间戳方法

			//给日历设置date日期：
			Date d= new Date();
			Calendar calendar = Calendar.getInstance();
			calendar.setTime(d);

			//给日历设置自定义日期：
			Calendar calendar2 = Calendar.getInstance();
			calendar2.set(Calendar.YEAR,2018);
			calendar2.set(Calendar.MONTH,11);//月份是从0开始的，所以11代表十二月
			calendar2.set(Calendar.DAY_OF_MONTH,20);//

			//日历转date
			Date calendar2Date = calendar2.getTime();
			String calendar2String = sdf.format(calendar2Date);
			System.out.println(">>>>>>>>>>"+calendar2String);//结果>>>>>>>>>>2018-12-20 17:20:12

			//间隔日期：

			Date date1 = new Date();
			Calendar cal = Calendar.getInstance();
			cal.setTime(date1);
			cal.add(Calendar.DATE,1);
			Date date2 = cal.getTime();

			long leftTime =  date2.getTime()-date1.getTime();
			System.out.println("时间戳间隔"+leftTime);
			//将时间戳间隔转换成时分秒，正在写。。

			Long hh=leftTime/(1000*60*60);
			Long mm=leftTime%(1000*60*60);
			String betueenTime=hh+"小时"+mm+"分";

			//倒计时：

		}catch (Exception e){

		}
	}
}

工具类：计算间隔时分秒：

package com.zzt.spider;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
/**
 * 时间工具总结
 * @author ZX
 * @date 2018年4月20日
 *
 */
public class TestTime {
	public static void main(String[] args) throws ParseException {
		//测试
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
		String timeStr1="2018-04-01 12:30:10";
		String timeStr2="2018-04-02 13:31:20";
		Date date1 = sdf.parse(timeStr1);
		Date date2 = sdf.parse(timeStr2);
		String dateBetween = dateBetween(date1, date2);
		System.out.println(dateBetween);

	}
	/**
	 *
	 * @param startDate 开始date
	 * @param endDate   结束date
	 * @return
	 */
	public static String dateBetween(Date startDate, Date endDate) {
		java.util.Calendar calStart = java.util.Calendar.getInstance();
		java.util.Calendar calEnd = java.util.Calendar.getInstance();

		calStart.setTime(startDate);
		calEnd.setTime(endDate);

		long diffMill = calEnd.getTime().getTime() - calStart.getTime().getTime();
		System.out.println("间隔的毫秒数："+diffMill);

		long rtn = 0;

		return formatTime(diffMill);
	}
    /*
     * 毫秒转化时分秒毫秒
     */
    public static String formatTime(Long ms) {
        Integer ss = 1000;
        Integer mi = ss * 60;
        Integer hh = mi * 60;
        Integer dd = hh * 24;  

        Long day = ms / dd;
        Long hour = (ms - day * dd) / hh;
        Long minute = (ms - day * dd - hour * hh) / mi;
        Long second = (ms - day * dd - hour * hh - minute * mi) / ss;
        Long milliSecond = ms - day * dd - hour * hh - minute * mi - second * ss;  

        StringBuffer sb = new StringBuffer();
        if(day > 0) {
            sb.append(day+"天");
        }
        if(hour > 0) {
            sb.append(hour+"小时");
        }
        if(minute > 0) {
            sb.append(minute+"分");
        }
        if(second > 0) {
            sb.append(second+"秒");
        }
        if(milliSecond > 0) {
            sb.append(milliSecond+"毫秒");
        }
        return sb.toString();
    }  

	public static Long dateDiff(Date sDate, Date eDate, int diffType) {
		java.util.Calendar calst = java.util.Calendar.getInstance();
		java.util.Calendar caled = java.util.Calendar.getInstance();

		calst.setTime(sDate);
		caled.setTime(eDate);

		long diffMill = caled.getTime().getTime() - calst.getTime().getTime();
		System.out.println("diffMill"+diffMill);
		long rtn = 0;
		switch (diffType) {
			case Calendar.MILLISECOND:
				rtn = diffMill;
				break;
			case Calendar.SECOND:
				rtn = diffMill / 1000;
				break;
			case Calendar.MINUTE:
				rtn = diffMill / 1000 / 60;
				break;
			case Calendar.HOUR:
				rtn = diffMill / 1000 / 3600;
				break;
			case Calendar.DATE:
				rtn = diffMill / 1000 / 60 / 60 / 24;
				break;
			case Calendar.MONTH:
				rtn = diffMill / 1000 / 60 / 60 / 24 / 12;
				break;
			case Calendar.YEAR:
				rtn = diffMill / 1000 / 60 / 60 / 24 / 365;
				break;
		}
		return rtn;
	}
}

获取某月第一天与最后一天：

/**
* 获得该月第一天
* @param year
* @param month
* @return
*/
public static String getFirstDayOfMonth(int year,int month){
        Calendar cal = Calendar.getInstance();
        //设置年份
        cal.set(Calendar.YEAR,year);
        //设置月份
        cal.set(Calendar.MONTH, month-1);
        //获取某月最小天数
        int firstDay = cal.getActualMinimum(Calendar.DAY_OF_MONTH);
        //设置日历中月份的最小天数
        cal.set(Calendar.DAY_OF_MONTH, firstDay);
        //格式化日期
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        String firstDayOfMonth = sdf.format(cal.getTime());
        return firstDayOfMonth;
    }  

/**
	 * 获取某年某月的最后一天
	 * @param year
	 * @param month
	 * @return
	 */
	public static String getLatDayOfMonth(int year ,int month) {
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		Calendar cal = Calendar.getInstance();
		//设置年份
	/*	cal.set(Calendar.YEAR,year);
		//设置月份
		cal.set(Calendar.MONTH, month-1);*/
		//获取某月最大天数
		// int lastDay = cal.getActualMaximum(Calendar.DAY_OF_MONTH);
		//设置日历中月份的最大天数
		// cal.set(Calendar.DAY_OF_MONTH, lastDay);
		//格式化日期
		cal.set(year, month-1, 1);
		cal.roll(Calendar.DATE, -1);

		String lastDayOfMonth = sdf.format(cal.getTime());
		return lastDayOfMonth;
	}