DateUtils工具类

package com.alphajuns.ssm.util;

import org.apache.commons.lang.time.DateFormatUtils;

import java.sql.Timestamp;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.List;

public class DateUtils {

    /**
     * <p>Field DATEPATTERNYYYYVMMVDD: change date to type "yyyy-MM-dd" </p>
     */
    public static final String DATEPATTERNYYYYVMMVDD = "yyyy-MM-dd";

    /**
     * <p>Field DATEPATTERNYYYYVMMVDD: change date to type "yyyy/MM/dd HH:mm:ss" </p>
     */
    public static final String DATEWITH_H_M_S = "yyyy-MM-dd HH:mm:ss";

    public static final String YYYY_MM_DD = "yyyy-MM-dd";

    /**
     * Description: 时间戳转日期字符串
     * @param t t
     * @param pattern pattern
     * @return String
     */
    public static String getDateFromTimestampByPattern(Timestamp t, String pattern) {
        if (t != null) {
            return DateFormatUtils.format(new Date(t.getTime()), pattern);
        } else {
            return null;
        }
    }

    /**
     * Description: 日期转日期字符串
     * @param t t
     * @param pattern pattern
     * @return String
     */
    public static String getStrFromDateByPattern(Date t, String pattern) {
        if (t != null) {
            return DateFormatUtils.format(t, pattern);
        } else {
            return null;
        }
    }

    /**
     * <p>Description:  将当前日期加减n天数。 如传入整型-5 意为将当前日期减去5天的日期 如传入整型5 意为将当前日期加上5天后的日期 返回字串 例(19990203)</p>
     * @param format format 格式化的类型    例如：2015-05-06 ，加7天  =2015-05-13
     * @param days days 天数
     * @return String
     */
    public static String dateAdd(int days, String format) {
        // 日期处理模块 (将日期加上某些天或减去天数)返回字符串
        Calendar calendar;
        calendar = Calendar.getInstance();
        // 设置负数时，进行减计算
        calendar.add(Calendar.DAY_OF_YEAR, days);

        SimpleDateFormat sdfd ;
        sdfd = new SimpleDateFormat(format);

        String formatDate;
        formatDate = sdfd.format(calendar.getTime());
        return formatDate;
    }

    /**
     * 得到最近几个月的时间区间
     * @param months
     * @param format
     * @return
     */
    public static String[] getRecentMonthDateScope(int months, String format){
        SimpleDateFormat sdfd ;
        sdfd = new SimpleDateFormat(format);
        // 日期处理模块 (将日期加上月数)返回字符串
        Calendar calendar;
        calendar = Calendar.getInstance();
        Date currentDate = calendar.getTime();
        String endDate;
        endDate = sdfd.format(currentDate);
        // 设置-3，往前推三个月
        calendar.add(Calendar.MONTH, -3);
        String startDate;
        startDate = sdfd.format(calendar.getTime());
        return new String[]{startDate,endDate};
    }

    /**
     * 计算工作日
     * 具体节日包含哪些,可以在HolidayMap中修改
     * @param date 日期(源)
     * @param adddays 要加的天数
     * @exception throws [违例类型] [违例说明]
     * @version  [s001, 2010-11-19]
     */
    public static Date addDateByWorkDay(Date date,int adddays) {
        if (date == null) {
            return null;
        }
        Calendar src = Calendar.getInstance();
        src.setTime(date);
        boolean holidayFlag = false;
        for (int i = 0; i < adddays; i++) {
            // 把源日期加一天
            src.add(Calendar.DAY_OF_MONTH, 1);
            holidayFlag = checkHoliday(src);
            if (holidayFlag) {
                i--;
            }
            System.out.println(src.getTime());
        }
        System.out.println("Final Result:"+src.getTime());
        return src.getTime();
    }

    /**
     * 校验指定的日期是否在节日列表中
     * 具体节日包含哪些,可以在HolidayMap中修改
     * @param src 要校验的日期(源)
     * @version  [s001, 2010-11-19]
     */
    public static boolean checkHoliday(Calendar src)
    {
        boolean result = false;
        // 先检查是否是周六周日(有些国家是周五周六)
        if (src.get(Calendar.DAY_OF_WEEK) == Calendar.SATURDAY
                || src.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY) {
            return true;
        }
        List<Calendar> holidayList = new ArrayList<Calendar>();
        for (Calendar c : holidayList) {
            if (src.get(Calendar.MONTH) == c.get(Calendar.MONTH)
                    && src.get(Calendar.DAY_OF_MONTH) == c.get(Calendar.DAY_OF_MONTH))
            {
                result = true;
            }
        }
        return result;
    }

    /**
     * <p>Description:  按格式将字符串转为Timestamp</p>
     * @param t t
     * @param pattern pattern
     * @return Timestamp
     */
    public static Timestamp getTimestampByPattern(String t, String pattern) {
        if (pattern == null || pattern.equals("")) {
            pattern = DATEWITH_H_M_S;
        }
        SimpleDateFormat sdf;
        sdf = new SimpleDateFormat(pattern);
        Date date = null;
        try {
            date = sdf.parse(t);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        if (date != null) {
            return new Timestamp(date.getTime());
        }
        return null;
    }

    /**
     * <p>Description:  按格式将字符串转为Timestamp</p>
     * @param t t
     * @param pattern pattern
     * @return Timestamp
     */
    public static Date getDateByPattern(String t, String pattern) {
        if (pattern == null || pattern.equals("")) {
            pattern = DATEPATTERNYYYYVMMVDD;
        }
        if (t == null || t.equals("") || t.equals("null")) {
            return null;
        }
        SimpleDateFormat sdf;
        sdf = new SimpleDateFormat(pattern);
        Date date = null;
        try {
            date = sdf.parse(t);
        } catch (ParseException e) {
            try {
                date = DateUtils.getDateByPattern(t, DATEPATTERNYYYYVMMVDD,"yyyy-MM-dd HH:mm:ss","yyyy-MM-dd HH:mm");
            } catch (Exception e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            }
        }
        return date;
    }

    /**
     * 从字符串获取日期，按时间来获取，从有秒的pattern开始，到只有天的pattern
     * @param t
     * @return
     * @throws Exception
     */
    public static Date getDateByDefaultPattern(String t) throws Exception{
        return DateUtils.getDateByPattern(t,"yyyy-MM-dd HH:mm:ss","yyyy-MM-dd HH:mm","yyyy-MM-dd");
    }

    /**
     * 按格式将字符串转为Timestamp
     * @param t
     * @param patterns
     * @return
     * @throws Exception
     */
    public static Timestamp getTimestampByPattern(String t, String ...patterns) throws Exception{
        Date  date = getDateByPattern(t, patterns);
        if(date!=null){
            Timestamp ts = new Timestamp(date.getTime());
            return ts;
        }else{
            return null;
        }
    }

    /**
     * 按格式将字符串转化为日期
     * @param t
     * @param patterns
     * @return
     * @throws Exception
     */
    public static Date getDateByPattern(String t, String ...patterns) throws Exception{
        if (patterns == null || patterns.equals("")) {
            patterns = new String[1];
            patterns[0] = DATEPATTERNYYYYVMMVDD;
        }
        if (t == null || t.equals("") || t.equals("null")){
            return null;
        }
        SimpleDateFormat sdf;
        Date date = null;
        for (String simplePattern : patterns) {
            try {
                sdf = new SimpleDateFormat(simplePattern);
                date = sdf.parse(t);
                Calendar c = Calendar.getInstance();
                c.setTime(date);
                int s = c.get(Calendar.YEAR);
                if (s == 1970) {
                    Calendar curr = Calendar.getInstance();
                    curr.setTime(new Date());
                    c.set(Calendar.YEAR, curr.get(Calendar.YEAR));
                    date = c.getTime();
                }
            } catch (ParseException e) {
                continue;
            }
            break;
        }
        return date;
    }


    /**
     * 获取指定格式的当前时间
     * @param format
     * @return
     */
    public static String getDayDate(String format) {
        SimpleDateFormat df ;
        df = new SimpleDateFormat(format);
        return df.format(new Date());

    }

    /**
     * 按格式将字符串时间转化为时间戳
     * @param t
     * @param pattern
     * @return
     */
    public static Timestamp getTimestamp(String t, String pattern) {
        SimpleDateFormat sdf;
        sdf = new SimpleDateFormat(pattern);
        Date date = null;
        try {
            date = sdf.parse(t);
        } catch (ParseException e) {
            e.printStackTrace();
        }

        if (date != null) {
            return new Timestamp(date.getTime());
        }
        return null;
    }

}

package com.alphajuns.junit;

import com.alphajuns.ssm.util.DateUtils;
import org.junit.Test;

import java.sql.Timestamp;
import java.util.Date;

public class DateUtilsTest {

    /**
     * 将时间戳转化为指定格式日期字符串
     */
    @Test
    public void getDateFromTimestampByPattern() {
        Timestamp timestamp = new Timestamp(System.currentTimeMillis());
        String yyyyMMdd = "yyyy-MM-dd";
        String yyyyMMddHHmmss = "yyyy-MM-dd HH:mm:ss";
        String dateStr1 = DateUtils.getDateFromTimestampByPattern(timestamp, yyyyMMdd);
        System.out.println(dateStr1);
        String dateStr2 = DateUtils.getDateFromTimestampByPattern(timestamp, yyyyMMddHHmmss);
        System.out.println(dateStr2);
    }

    /**
     * 按指定格式获取日期字符串
     */
    @Test
    public void getStrFromDateByPattern() {
        String dateStr1 = DateUtils.getStrFromDateByPattern(new Date(), "yyyy-MM-dd");
        System.out.println(dateStr1);
        String dateStr2 = DateUtils.getStrFromDateByPattern(new Date(), "yyyy-MM-dd HH:mm:ss");
        System.out.println(dateStr2);
    }

    /**
     * 日期加减计算
     */
    @Test
    public void dateAdd() {
        String dateStr1 = DateUtils.dateAdd(25, "yyyy-MM-dd");
        System.out.println(dateStr1);
        String dateStr2 = DateUtils.dateAdd(-13, "yyyy-MM-dd HH:mm:ss");
        System.out.println(dateStr2);
    }

    /**
     * 获取当前日期所在区间
     */
    @Test
    public void getRecentMonthDateScope() {
        String dateStr[] = DateUtils.getRecentMonthDateScope(8, "yyyy-MM-dd");
        for (int i = 0; i < dateStr.length; i++) {
            System.out.println(dateStr[i]);
        }
    }

    /**
     * 按指定格式将日期转化为时间戳
     */
    @Test
    public void getTimestampByPattern() {
        Timestamp timestamp1 = DateUtils.getTimestampByPattern("2020-06-10 09:44:54", "");
        System.out.println(timestamp1);
        Timestamp timestamp2 = DateUtils.getTimestampByPattern("2020-06-10 09:44:54", "yyyy-MM-dd");
        System.out.println(timestamp2);
    }

    /**
     * 获取当前时间
     */
    @Test
    public void getDayDate() {
        String dayDate = DateUtils.getDayDate("yyyy-MM-dd");
        System.out.println(dayDate);
    }

    /**
     * 按指定格式将日期转化为时间戳
     */
    @Test
    public void getTimestamp() {
        Timestamp timestamp = DateUtils.getTimestamp("2020-06-10", "yyyy-MM-dd");
        System.out.println(timestamp);
    }

    /**
     * 按格式将字符串转化为日期
     */
    @Test
    public void getDateByPattern() {
        Date date1 = DateUtils.getDateByPattern("2020-06-10 10:15:20", "yyyy-MM-dd HH:mm:ss");
        System.out.println(date1);
        Date date2 = DateUtils.getDateByPattern("2020-06-10", "");
        System.out.println(date2);
    }

}