Java中常用的日期操作方法

日常项目当中经常会用到操作日期，抽出时间总结了一下，欢迎和大家多多沟通学习，如有任何改进意见和建议，我的QQ是1243672，欢迎联系哦。

/**

 * 日期操作类

 * 开发公司:北京东达悦科技有限公司

 * 开发人:宋海鹏

 * 最后更新日期:2013-09-10

 */

package com.imstudio.common;



import java.text.ParseException;

import java.text.SimpleDateFormat;

import java.util.Date;



public class DatetimeHelper {



    private static String datePattern = "yyyy-MM-dd";

    private static String timePattern = datePattern + " HH:mm:ss";

    private static String minDate = "1900-01-01";



    public static String getDatePattern() {

        return datePattern;

    }



    public static String getTimePattern() {

        return timePattern;

    }



    public static final String DatetimeToString(Date date, String pattern) {

        SimpleDateFormat df = null;

        String dateString = "";

        if (date != null) {

            df = new SimpleDateFormat(pattern);

            dateString = df.format(date);

        }

        return dateString;

    }



    public static final String DateToString(Date date) {

        return DatetimeToString(date, datePattern);

    }



    public static final String DatetimeToString(Date date) {

        return DatetimeToString(date, timePattern);

    }



    public static final Date StringToDatetime(String date, String pattern) {

        SimpleDateFormat df = null;

        Date dateValue = null;

        df = new SimpleDateFormat(pattern);

        try {

            dateValue = (Date) df.parse(date);

        } catch (ParseException pre) {

            return null;

        }



        return dateValue;

    }



    public static final Date StringToDate(String date) {

        return StringToDatetime(date, datePattern);

    }



    public static final Date StringToDatetime(String date) {

        return StringToDatetime(date, timePattern);

    }



    public static final String Now(String pattern) {

        Date dt = new Date();

        SimpleDateFormat df = new SimpleDateFormat(pattern);

        return df.format(dt);

    }



    public static final String Now() {

        return Now(timePattern);

    }



    public static final String Today() {

        return Now(datePattern);

    }



    public static final String Today(String pattern) {

        return Now(pattern);

    }



    public static final Date MinDate() {

        return StringToDate(minDate);

    }



    public static final Long DateDiff(Date start, Date end) {

        long days = 0;

        days = (start.getTime() - end.getTime()) / (60 * 60 * 24 * 1000);

        return days;

    }



    public static final Long DateDiff(String start, String end) {

        return DateDiff(StringToDatetime(start), StringToDatetime(end));

    }



    public static final Long DateDiff(String end) {

        return DateDiff(StringToDatetime(Today()), StringToDatetime(end));

    }



    @SuppressWarnings("deprecation")

    public static final Long Age(Date today, Date birthday) {

        long age = 0;

        age = today.getYear() - birthday.getYear();

        if (today.getMonth() == birthday.getMonth()) {

            age = (today.getDay() < birthday.getDay()) ? age - 1 : age;

        } else {

            age = (today.getMonth() > birthday.getMonth()) ? age : age - 1;

        }

        return age;

    }

}