java 对日期处理

引入依赖

<dependency>
   <groupId>joda-time</groupId>
   <artifactId>joda-time</artifactId>
   <version>2.9.9</version>
</dependency>

使用 joda-time 线程安全

工具类：

import org.apache.commons.lang3.StringUtils;
import org.joda.time.DateTime;
import org.joda.time.Days;
import org.joda.time.Minutes;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;

import javax.xml.datatype.DatatypeFactory;
import javax.xml.datatype.XMLGregorianCalendar;
import java.sql.Timestamp;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

/**
 * 日期帮助类，用于对日期以及字符串的相关操作
 */
public class DateUtil {

    /**
     * compare two days
     * if first bigger than second return > 0 else return < 0
     */
    public static int compareDates(Date first, Date second) {
        if (first.getTime() > second.getTime()) {
            return 1;
        } else if (first.getTime() < second.getTime()) {
            return -1;
        } else {
            return 0;
        }
    }

    /**
     * 功能描述：返回分
     *
     * @param date 日期
     * @return 返回分钟
     */
    public static int getMinute(Date date) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        return calendar.get(Calendar.MINUTE);
    }

    /**
     * 获取小时
     *
     * @param date
     * @return
     */
    public static int getHour(Date date) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        return calendar.get(Calendar.HOUR_OF_DAY);
    }


    /**
     * 字符串转换成日期
     * "yyyy-MM-dd HH:mm:ss"
     *
     * @param str
     * @return date
     */
    public static Date stringToDate(String str, String dateFormat) {
        Date date = null;
        try {
            if (StringUtils.isNotEmpty(str)) {
                DateTimeFormatter format = DateTimeFormat.forPattern(dateFormat);
                DateTime dateTime = DateTime.parse(str, format);
                date = dateTime.toDate();
            }
        } catch (Exception e) {

        }
        return date;
    }


    public static Date stringToDate(String str) {
        Date date = null;
        try {
            if (StringUtils.isNotEmpty(str)) {
                DateTime dateTime = DateTime.parse(str);
                date = dateTime.toDate();
            }
        } catch (Exception e) {

        }
        return date;
    }

    /**
     * 日期转换成字符串
     *
     * @param date
     * @param strFormat
     * @return
     */
    public static String dateToString(Date date, String strFormat) {
        DateTime dateTime = new DateTime(date);
        return dateTime.toString(strFormat);
    }

    /**
     * 获取
     *
     * @param date
     * @param n
     * @return
     */
    public static Date addDays(Date date, int n) {
        DateTime dateTime = new DateTime(date);
        return dateTime.plusDays(n).toDate(); //把日期往后增加n天.正数往后推,负数往前移动
    }

    public static Date addYears(Date date, int var1) {
        DateTime dateTime = new DateTime(date);
        return dateTime.plusYears(var1).toDate(); //把日期往后增加n天.正数往后推,负数往前移动
    }

    /**
     * 计算相差分钟
     *
     * @param var0
     * @param var1
     * @return
     */
    public static int minutesBetween(Date var0, Date var1) {
        if (var0 != null && var1 != null)
            return Minutes.minutesBetween(new DateTime(var0), new DateTime(var1)).getMinutes();
        return 0;
    }

    /**
     * 计算相差天数
     *
     * @param var0
     * @param var1
     * @return
     */
    public static int daysBetween(Date var0, Date var1) {
        return Days.daysBetween(new DateTime(var0), new DateTime(var1)).getDays();
    }

    /**
     * 获取星期
     *
     * @param var1
     * @return
     */
    public static String getDayOfWeek(Date var1) {
        DateTime dateTime = new DateTime(var1);
        return dateTime.dayOfWeek().getAsString();
    }

    /*
     * 生成日期对象
     */
    public static XMLGregorianCalendar convertToXMLGregorianCalendar(Date date) {
        XMLGregorianCalendar gc = null;
        try {
            GregorianCalendar cal = new GregorianCalendar();
            cal.setTime(date);
            gc = DatatypeFactory.newInstance().newXMLGregorianCalendar(cal);
        } catch (Exception e) {
        }
        return gc;
    }

    public static Calendar dateToCalendar(Timestamp timestamp) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(timestamp);
        return calendar;
    }
}