DateUtils.java

/*******************************************************************************
 * Copyright 2015 htd0324@gmail.com
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/
package com.laudandjolynn.mytv.utils;

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

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author: Laud
 * @email: htd0324@gmail.com
 * @date: 2012-9-11 下午3:28:34
 * @copyright: www.dreamoriole.com
 */
public class DateUtils {
	private final static Logger logger = LoggerFactory
			.getLogger(DateUtils.class);
	// 默认时间格式
	public static final String DEFAULT_DATE_PATTERN = "yyyy-MM-dd HH:mm:ss";

	/**
	 * 获取当天的日期字符串，yyyy-MM-dd
	 * 
	 * @return
	 */
	public static String today() {
		return DateUtils.date2String(Calendar.getInstance().getTime(),
				"yyyy-MM-dd");
	}

	/**
	 * 获取明天的日期字符串，yyyy-MM-dd
	 * 
	 * @return
	 */
	public static String tommorow() {
		Calendar calendar = Calendar.getInstance();
		calendar.add(Calendar.DAY_OF_MONTH, 1);
		return DateUtils.date2String(calendar.getTime(), "yyyy-MM-dd");
	}

	/**
	 * 字符串转为时间
	 * 
	 * @param date
	 * @param pattern
	 * @return
	 */
	public static Date string2Date(String date, String pattern) {
		SimpleDateFormat format = new SimpleDateFormat(pattern);
		try {
			return format.parse(date);
		} catch (ParseException e) {
			logger.error("invalid date value: " + date, e);
		}
		return null;
	}

	/**
	 * 字符串转为时间
	 * 
	 * @param date
	 * @return
	 */
	public static Date string2Date(String date) {
		return string2Date(date, DEFAULT_DATE_PATTERN);
	}

	/**
	 * 时间转为字符串
	 * 
	 * @param date
	 * @return yyyy-MM-dd HH:mm:ss格式
	 */
	public static String date2String(Date date) {
		SimpleDateFormat formatter = new SimpleDateFormat(DEFAULT_DATE_PATTERN);
		formatter.setTimeZone(TimeZone.getDefault());
		return formatter.format(date);
	}

	/**
	 * 时间转为字符串
	 * 
	 * @param date
	 * @param pattern
	 *            时间样式
	 * @return
	 */
	public static String date2String(Date date, String pattern) {
		SimpleDateFormat formatter = new SimpleDateFormat(pattern);
		formatter.setTimeZone(TimeZone.getDefault());
		return formatter.format(date);
	}

	/**
	 * 获取指定時間一周的日期列表
	 * 
	 * @param date
	 * @return
	 */
	public static Date[] getWeek(Date date) {
		Date[] dates = new Date[7];
		Calendar calendar = Calendar.getInstance();
		calendar.setTime(date);
		calendar.setFirstDayOfWeek(Calendar.MONDAY);
		calendar.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
		for (int i = 0; i < 7; i++) {
			dates[i] = calendar.getTime();
			calendar.add(Calendar.DAY_OF_YEAR, 1);
		}
		return dates;
	}

	/**
	 * 获取指定时间的下一周头一天, 每周第一天为星期一
	 * 
	 * @param date
	 * @return
	 */
	public static Date nextWeek(Date date) {
		Calendar calendar = Calendar.getInstance();
		calendar.setTime(date);
		calendar.setFirstDayOfWeek(Calendar.MONDAY);
		calendar.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
		calendar.add(Calendar.WEEK_OF_YEAR, 1);
		return calendar.getTime();
	}

	/**
	 * 获取指定时间一周的日期列表，每周第一天为星期一
	 * 
	 * @param date
	 * @param pattern
	 * @return
	 */
	public static String[] getWeek(Date date, String pattern) {
		Date[] dates = getWeek(date);
		String[] result = new String[dates.length];
		for (int i = 0; i < 7; i++) {
			result[i] = date2String(dates[i], pattern);
		}
		return result;
	}

	/**
	 * 给指定日期加/减年
	 * 
	 * @param date
	 * @param year
	 *            正数加，负数减
	 * @return
	 */
	public static Date addYear(Date date, int year) {
		Calendar calendar = Calendar.getInstance();
		calendar.setTime(date);
		calendar.add(Calendar.YEAR, year);
		return calendar.getTime();
	}

	/**
	 * 给指定日期加/减指定月
	 * 
	 * @param date
	 * @param month
	 *            正数加，负数减
	 * @return
	 */
	public static Date addMonth(Date date, int month) {
		Calendar calendar = Calendar.getInstance();
		calendar.setTime(date);
		calendar.add(Calendar.MONTH, month);
		return calendar.getTime();
	}

	/**
	 * 给指定日期加/减指定天数
	 * 
	 * @param date
	 * @param day
	 *            正数加，负数减
	 * @return
	 */
	public static Date addDay(Date date, int day) {
		Calendar calendar = Calendar.getInstance();
		calendar.setTime(date);
		calendar.add(Calendar.DAY_OF_MONTH, day);
		return calendar.getTime();
	}

	/**
	 * 计算两个指定日期相差几天
	 * 
	 * @param arg0
	 * @param arg1
	 * @return 返回大减小的相差天数
	 */
	public static long differHowManyDays(Date arg0, Date arg1) {
		long d1 = arg0.getTime();
		long d2 = arg1.getTime();

		return Math.abs(d1 - d2) / (60 * 60 * 24 * 1000);
	}

	/**
	 * 取得一天的开始时间
	 * 
	 * @param date
	 * @return
	 */
	public static Date getStartOfTheDay(Date date) {
		String value = date2String(date, "yyyy-MM-dd 00:00:00");
		return string2Date(value);
	}

	/**
	 * 取得一天的结束时间
	 * 
	 * @param date
	 * @return
	 */
	public static Date getEndOfTheDay(Date date) {
		String value = date2String(date, "yyyy-MM-dd 23:59:59");
		return string2Date(value);
	}

	/**
	 * 取得指定月份的第一天
	 * 
	 * @param date
	 * @return
	 */
	public static Date getFirstDayOfTheMonth(Date date) {
		String value = date2String(date, "yyyy-MM-01 00:00:00");
		return string2Date(value);
	}

	/**
	 * 取得指定月份的最后一天
	 * 
	 * @param date
	 * @return
	 */
	public static Date getLastDayOfTheMonth(Date date) {
		Calendar calendar = Calendar.getInstance();
		calendar.setTime(date);
		int lastDay = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
		calendar.set(calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH),
				lastDay, 0, 0, 0);
		return calendar.getTime();
	}

}