java获取当年第一天

/**
* 当前月第一天
*
* @return 当前月第一天
*/
public String getThisMonth() {
// 获取前月的第一天
Calendar calendar = Calendar.getInstance();
SimpleDateFormat format = new SimpleDateFormat(“yyyy-MM-dd”);
calendar.add(Calendar.MONTH, 0);
calendar.set(Calendar.DAY_OF_MONTH, 1);// 设置为1号,当前日期既为本月第一天
String firstDay = format.format(calendar.getTime());
return firstDay;
}

/** * 日期是本月的第几天 *  * @param date *            天 * @return 当前天数 * @throws ParseException *             数据转换异常 */public static String getMostDay(String date) throws ParseException {    // 当天日期是本月的第几天    SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");    Date nowDay = format.parse(date);    Calendar ca = Calendar.getInstance();    ca.setTime(nowDay);    int num = ca.get(Calendar.DAY_OF_MONTH);    String time = String.valueOf(num);    return time;}/** * 获取日期在当月天数 *  * @param date *            天 * @return 当月天数 * @throws Exception *             异常 */public static String getMonthDay(String date) throws Exception {    // 当前月最大日期    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");    Date dates = sdf.parse(date);// String-->Date    Calendar calendar = Calendar.getInstance();    calendar.setTime(dates);// 设置日历时间    int day = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);    String mostDate = String.valueOf(day);    return mostDate;}/** * 当年第一天 *  * @param date *            日期 * @return 天 * @throws Exception *             异常 */public static String getThisYear(String date) throws Exception {    SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");    SimpleDateFormat format3 = new SimpleDateFormat("yyyy");    Date time = format3.parse(date);    String time1 = format3.format(time);    Date startTime = format.parse(time1 + "-01-01");    String dates = format.format(startTime);    return dates;}/** * 当月第一天 *  * @param date *            天 * @return 天 * @throws ParseException *             异常 */public static String getFirstDayToMonth(String date) throws ParseException {    // 获取截止当前天数    SimpleDateFormat format = new SimpleDateFormat("yyyy-MM");    Date nowDay = format.parse(date);    String time = format.format(nowDay);    String firstDay = time + "-01";    return firstDay;}/** * 当年第一天 *  * @param date *            天 * @return 天 * @throws ParseException *             异常 */public static String getFirstDay(String date) throws ParseException {    // 获取截止当前天数    SimpleDateFormat format = new SimpleDateFormat("yyyy");    Date nowDay = format.parse(date);    String time = format.format(nowDay);    String firstDay = time + "-01-01";    return firstDay;}/** * 获取日期到年初的天数 *  * @param date *            天 * @return 天数 * @throws Exception *             异常 */public static int getDayCount(String date) throws Exception {    // 获取截止当前天数    SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");    String year = date.substring(0, ConstantUtils.CUT_OUT);    String starttime = year + "-01-01 00:00:00";    String endtime = date + " 00:00:00";    Date d1 = format.parse(starttime);    Date d2 = format.parse(endtime);    long s1 = d1.getTime();    long s2 = d2.getTime();    int days = (int) ((s2 - s1) / ConstantUtils.EVERYDAY_SECONF);    return days;}/** * 月底到年初的天数 *  * @param date *            天 * @return 天 * @throws Exception *             异常 */public static int getYearCount(String date) throws Exception {    String count = getMonthDay(date);    String firstDay = getFirstDay(date);    SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");    SimpleDateFormat format2 = new SimpleDateFormat("yyyy-MM");    long startTime = format.parse(firstDay).getTime();    long endTime = format2.parse(date).getTime();    String string = format2.format(endTime);    Date dates = format.parse(string + "-" + count);    long endMonthTime = dates.getTime();    long dayMonth = (endMonthTime - startTime) / ConstantUtils.EVERYDAY_SECONF;    return (int) dayMonth;}/** * 获取给定日起前一天 *  * @param date *            天 * @return 天 * @throws ParseException *             异常 */public static String getYesterDay(String date) throws ParseException {    // 获取给定日起过去15天    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");    Calendar cal = Calendar.getInstance();    Date dateTemp = sdf.parse(date);    cal.setTime(dateTemp);    cal.add(Calendar.DATE, ConstantUtils.MINUS_1);    Date dates = cal.getTime();    String yesterDay = sdf.format(dates);    return yesterDay;}/** * 获取给定日起前一周 *  * @param date *            天 * @return 天 * @throws ParseException *             异常 */public static String getLastWeekDay(String date) throws ParseException {    // 获取给定日起过去15天    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");    Calendar cal = Calendar.getInstance();    Date dateTemp = sdf.parse(date);    cal.setTime(dateTemp);    cal.add(Calendar.DATE, ConstantUtils.MINUS_7);    Date dates = cal.getTime();    String yesterDay = sdf.format(dates);    return yesterDay;}/** * 获取给定日起过去15天 *  * @param date *            天 * @return 天 * @throws ParseException *             异常 */public static String getLastFifthDay(String date) throws ParseException {    // 获取给定日起过去15天    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");    Calendar cal = Calendar.getInstance();    Date dateTemp = sdf.parse(date);    cal.setTime(dateTemp);    cal.add(Calendar.DATE, ConstantUtils.MINUS_15); // -15    Date dates = cal.getTime();    String lastFifthDay = sdf.format(dates);    return lastFifthDay;}/** * 获取给定日起一个月 *  * @param date *            天 * @return 天 * @throws ParseException *             异常 */public static String getLastMonthDay(String date) throws ParseException {    // 获取给定日起过去15天    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");    Calendar cal = Calendar.getInstance();    Date dateTemp = sdf.parse(date);    cal.setTime(dateTemp);    cal.add(Calendar.MONTH, ConstantUtils.MINUS_1); // -1,1个月前    Date dates = cal.getTime();    String lastHalfYearDay = sdf.format(dates);    return lastHalfYearDay;}/** * 获取给定日起3个月 *  * @param date *            天 * @return 天 * @throws ParseException *             异常 */public static String getLastThreeMonthsDay(String date) throws ParseException {    // 获取给定日起过去15天    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");    Calendar cal = Calendar.getInstance();    Date dateTemp = sdf.parse(date);    cal.setTime(dateTemp);    cal.add(Calendar.MONTH, ConstantUtils.MINUS_3); // -1,1个月前    Date dates = cal.getTime();    String lastHalfYearDay = sdf.format(dates);    return lastHalfYearDay;}/** * 获取给定日起过去半年 *  * @param date *            天 * @return 天 * @throws ParseException *             异常 */public static String getLasthalfYearDay(String date) throws ParseException {    // 获取给定日起过去15天    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");    Calendar cal = Calendar.getInstance();    Date dateTemp = sdf.parse(date);    cal.setTime(dateTemp);    cal.add(Calendar.MONTH, ConstantUtils.MINUS_6); //-6,6个月前    Date dates = cal.getTime();    String lastHalfYearDay = sdf.format(dates);    return lastHalfYearDay;}/** * 获取给定日去年同期 *  * @param date *            天 * @return 天 * @throws ParseException *             异常 */public static String getToLastYearDay(String date) throws ParseException {    // 获取给定日起过去15天    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");    Calendar cal = Calendar.getInstance();    Date dateTemp = sdf.parse(date);    cal.setTime(dateTemp);    cal.add(Calendar.YEAR, -1);    Date dates = cal.getTime();    String toLastYearDay = sdf.format(dates);    return toLastYearDay;}