Android-DateUtil工具类

public class DateUtil {

    private DateUtil(){}

    /**
     * 枚举日期格式
     */
    public enum DatePattern{
        /**
         * 格式："yyyy-MM-dd HH:mm:ss"
         */
        ALL_TIME{public String getValue(){return "yyyy-MM-dd HH:mm:ss";}},
        /**
         * 格式："yyyy-MM"
         */
        ONLY_MONTH{public String getValue(){return "yyyy-MM";}},
        /**
         * 格式："yyyy-MM-dd"
         */
        ONLY_DAY{public String getValue(){return "yyyy-MM-dd";}},
        /**
         * 格式："yyyy-MM-dd HH"
         */
        ONLY_HOUR{public String getValue(){return "yyyy-MM-dd HH";}},
        /**
         * 格式："yyyy-MM-dd HH:mm"
         */
        ONLY_MINUTE{public String getValue(){return "yyyy-MM-dd HH:mm";}},
        /**
         * 格式："MM-dd"
         */
        ONLY_MONTH_DAY{public String getValue(){return "MM-dd";}},
        /**
         * 格式："MM-dd HH:mm"
         */
        ONLY_MONTH_SEC{public String getValue(){return "MM-dd HH:mm";}},
        /**
         * 格式："HH:mm:ss"
         */
        ONLY_TIME{public String getValue(){return "HH:mm:ss";}},
        /**
         * 格式："HH:mm"
         */
        ONLY_HOUR_MINUTE{public String getValue(){return "HH:mm";}};
        public abstract String getValue();
    }

    /**
     * 获取当前时间
     * @return    返回当前时间，格式2017-05-04    10:54:21
     */
    public static String getNowDate(DatePattern pattern){
        String dateString = null;
        Calendar calendar = Calendar.getInstance();
        Date dateNow = calendar.getTime();
        SimpleDateFormat sdf = new SimpleDateFormat(pattern.getValue(),Locale.CHINA);
        dateString = sdf.format(dateNow);
        return dateString;
    }

    /**
     * 将一个日期字符串转换成Data对象
     * @param dateString    日期字符串
     * @param pattern        转换格式
     * @return    返回转换后的日期对象
     */
    public static Date stringToDate(String dateString, DatePattern pattern){
        Date date = null;
        SimpleDateFormat sdf = new SimpleDateFormat(pattern.getValue(),Locale.CHINA);
        try {
            date = sdf.parse(dateString);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return date;
    }

    /**
     * 将date转换成字符串
     * @param date    日期
     * @param pattern    日期的目标格式
     * @return
     */
    public static String dateToString(Date date, DatePattern pattern){
        String string = "";
        SimpleDateFormat sdf = new SimpleDateFormat(pattern.getValue(), Locale.CHINA);
        string = sdf.format(date);
        return string;
    }

    /**
     * 获取指定日期周几
     * @param date    指定日期
     * @return
     * 返回值为： "周日", "周一", "周二", "周三", "周四", "周五", "周六"
     */
    public static String getWeekOfDate(Date date){
        String[] weekDays = { "周日", "周一", "周二", "周三", "周四", "周五", "周六" };
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        int week = calendar.get(Calendar.DAY_OF_WEEK) - 1;
        if (week < 0)
            week = 0;
        return weekDays[week];
    }

    /**
     * 获取指定日期对应周几的序列
     * @param date    指定日期
     * @return    周一：1    周二：2    周三：3    周四：4    周五：5    周六：6    周日：7
     */
    public static int getIndexWeekOfDate(Date date){
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        int index = calendar.get(Calendar.DAY_OF_WEEK);
        if(index == 1){
            return 7;
        }else{
            return --index;
        }
    }

    /**
     * 返回当前月份
     * @return
     */
    public static int getNowMonth(){
        Calendar calendar = Calendar.getInstance();
        return calendar.get(Calendar.MONTH) + 1;
    }

    /**
     * 获取当前月号
     * @return
     */
    public static int getNowDay(){
        Calendar calendar = Calendar.getInstance();
        return calendar.get(Calendar.DATE);
    }

    /**
     * 获取当前年份
     * @return
     */
    public static int getNowYear(){
        Calendar calendar = Calendar.getInstance();
        return calendar.get(Calendar.YEAR);
    }

    /**
     * 获取本月份的天数
     * @return
     */
    public static int getNowDaysOfMonth(){
        Calendar calendar = Calendar.getInstance();
        return daysOfMonth(calendar.get(Calendar.YEAR),calendar.get(Calendar.DATE) + 1);
    }

    /**
     * 获取指定月份的天数
     * @param year    年份
     * @param month    月份
     * @return    对应天数
     */
    public static int daysOfMonth(int year,int month){
        switch(month){
            case 1:
            case 3:
            case 5:
            case 7:
            case 8:
            case 10:
            case 12:
                return 31;
            case 4:
            case 6:
            case 9:
            case 11:
                return 30;
            case 2:
                if((year % 4 ==0 && year % 100 == 0) || year % 400 != 0){
                    return 29;
                }else{
                    return 28;
                }
            default:
                return -1;
        }
    }
}