常用Calendar 操作日期的方法
package date;import java.text.SimpleDateFormat;import java.util.ArrayList;import java.util.Calendar;import java.util.Date;import java.util.GregorianCalendar;import java.util.LinkedHashMap;/** * 日期公用处理类 * * @author SongJun * @version 1.3 */public class DateUtil { public static void main(String args[]){ System.out.println(DateUtil.getMonthList("2000-10", "2001-6").toString()); System.out.println(DateUtil.getDayList("2000-8-1", "2000-8-10").toString()); System.out.println(DateUtil.getYearList().toString()); System.out.println(DateUtil.getCurrYear()); Calendar c = Calendar.getInstance(); c.set(Calendar.YEAR, 2010); c.set(Calendar.MONTH, 5);//11代表12月 c.set(Calendar.DATE, 3);//时间重新设置成2008-1-18 Date d = c.getTime(); System.out.println(DateUtil.getWeekOfYear(d)); System.out.println(DateUtil.getWeekCountInYear(2010)); System.out.println(DateUtil.getFirstDayOfWeek(d)); System.out.println(DateUtil.getFirstDayOfWeek(2008,3));//找第3行,的星期一 } /** * 解析一个日期段之间的所有月份 * * @param beginDateStr * @param endDateStr * @return */ public static ArrayList getMonthList(String beginDateStr, String endDateStr) { // 指定要解析的时间格式 SimpleDateFormat f = new SimpleDateFormat("yyyy-MM"); // 返回的月份列表 String sRet = ""; // 定义一些变量 Date beginDate = null; Date endDate = null; GregorianCalendar beginGC = null; GregorianCalendar endGC = null; ArrayList list = new ArrayList(); try { // 将字符串parse成日期 beginDate = f.parse(beginDateStr); endDate = f.parse(endDateStr); // 设置日历 beginGC = new GregorianCalendar(); beginGC.setTime(beginDate); endGC = new GregorianCalendar(); endGC.setTime(endDate); // 直到两个时间相同 while (beginGC.getTime().compareTo(endGC.getTime()) <= 0) {//如果参数 Date 等于此 Date，则返回值 0；如果此 Date 在 Date 参数之前，则返回小于 0 的值；如果此 Date 在 Date 参数之后，则返回大于 0 的值。 sRet = beginGC.get(Calendar.YEAR) + "-" + (beginGC.get(Calendar.MONTH) + 1); list.add(sRet); // 以月为单位，增加时间 beginGC.add(Calendar.MONTH, 1); } return list; } catch (Exception e) { e.printStackTrace(); return null; } } /** * 解析一个日期段之间的所有日期 * * @param beginDateStr * 开始日期 * @param endDateStr * 结束日期 * @return */ public static ArrayList getDayList(String beginDateStr, String endDateStr) { // 指定要解析的时间格式 SimpleDateFormat f = new SimpleDateFormat("yyyy-MM-dd"); // 定义一些变量 Date beginDate = null; Date endDate = null; Calendar beginGC = null; Calendar endGC = null; ArrayList list = new ArrayList(); try { // 将字符串parse成日期 beginDate = f.parse(beginDateStr); endDate = f.parse(endDateStr); // 设置日历 beginGC = Calendar.getInstance(); beginGC.setTime(beginDate); endGC = Calendar.getInstance(); endGC.setTime(endDate); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); // 直到两个时间相同 while (beginGC.getTime().compareTo(endGC.getTime()) <= 0) { list.add(sdf.format(beginGC.getTime())); // 以日为单位，增加时间 beginGC.add(Calendar.DAY_OF_MONTH, 1); } return list; } catch (Exception e) { e.printStackTrace(); return null; } } /** * * 今年开始 * @param 5 过去几年 * * @param 10 后来几年 * * @return */ public static ArrayList getYearList() { ArrayList list = new ArrayList(); Calendar c = null; c = Calendar.getInstance(); c.setTime(new Date()); int currYear = Calendar.getInstance().get(Calendar.YEAR); int startYear = currYear - 5; int endYear = currYear + 10; for (int i = startYear; i < endYear; i++) { list.add(new Integer(i)); } return list; } //获得当年 public static int getCurrYear() { return Calendar.getInstance().get(Calendar.YEAR); } /** * 取得当前日期是多少周 * * @param date * @return */ public static int getWeekOfYear(Date date) { Calendar c = new GregorianCalendar(); c.setFirstDayOfWeek(Calendar.SUNDAY);//设置一星期的第一天是哪一天；既日历的开头是哪一天 c.setMinimalDaysInFirstWeek(5);//设置一年中第一个星期所需的最少天数 ; 你自己开日历看看这年,头上有几个数字,设置一下; c.setTime(date); return c.get(Calendar.WEEK_OF_YEAR);// 哪个是第一周呢? 日历里的第1行; 得到的是这个Date 对象 ,位于日历的第几行 } /** * 得到一年的总周数 * @param year * @return */ public static int getWeekCountInYear(int year){ Calendar c = new GregorianCalendar(); c.set(year, Calendar.DECEMBER, 31, 23, 59, 59); int count = getWeekOfYear(c.getTime()); return count; } /** * 取得当前日期所在周的第一天 * * @param date * @return */ public static Date getFirstDayOfWeek(Date date) { Calendar c = new GregorianCalendar(); c.setFirstDayOfWeek(Calendar.MONDAY); c.setTime(date); c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek()); // Monday 它就会自动找这个星期的 return c.getTime(); } /** * 取得当前日期所在周的最后一天 * * @param date * @return */ public static Date getLastDayOfWeek(Date date) { Calendar c = new GregorianCalendar(); c.setFirstDayOfWeek(Calendar.MONDAY); c.setTime(date); c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek() + 6); // Sunday 它就会自动找这个星期的 return c.getTime(); } /** * 得到某年某周的第一天 * * @param year * @param week * @return */ public static Date getFirstDayOfWeek(int year, int week) { Calendar c = new GregorianCalendar(); c.set(Calendar.YEAR, year); c.set(Calendar.MONTH, Calendar.JANUARY); c.set(Calendar.DATE, 1); Calendar cal = (GregorianCalendar) c.clone(); cal.add(Calendar.DATE, week * 7); return getFirstDayOfWeek(cal.getTime()); } /** * 得到某年某周的最后一天 * * @param year * @param week * @return */ public static Date getLastDayOfWeek(int year, int week) { Calendar c = new GregorianCalendar(); c.set(Calendar.YEAR, year); c.set(Calendar.MONTH, Calendar.JANUARY); c.set(Calendar.DATE, 1); Calendar cal = (GregorianCalendar) c.clone(); cal.add(Calendar.DATE, week * 7); return getLastDayOfWeek(cal.getTime()); } /** * 得到某一年周的总数 * * @param year * @return */ public static LinkedHashMap getWeekList(int year) { LinkedHashMap map = new LinkedHashMap(); Calendar c = new GregorianCalendar(); c.set(year, Calendar.DECEMBER, 31, 23, 59, 59); int count = getWeekOfYear(c.getTime()); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); String dayOfWeekStart = ""; String dayOfWeekEnd = ""; for (int i = 1; i <= count; i++) { dayOfWeekStart = sdf.format(getFirstDayOfWeek(year, i));//格式化 某年某周的第一天 dayOfWeekEnd = sdf.format(getLastDayOfWeek(year, i));////格式化 某年某周的最后一天 map.put(new Integer(i), "第"+i+"周(从"+dayOfWeekStart + "至" + dayOfWeekEnd+")"); } return map; } /** * 得到某年某月的第一天 * @param year * @param month * @return */ public static Date getFirestDayOfMonth(int year,int month){ month = month-1; Calendar c = Calendar.getInstance(); c.set(Calendar.YEAR, year); c.set(Calendar.MONTH, month); int day = c.getActualMinimum(c.DAY_OF_MONTH);//返回指定日历字段可能拥有的最小值 c.set(Calendar.DAY_OF_MONTH, day); return c.getTime(); } /** * 提到某年某月的最后一天 * @param year * @param month * @return */ public static Date getLastDayOfMonth(int year,int month){ month = month-1; Calendar c = Calendar.getInstance(); c.set(Calendar.YEAR, year); c.set(Calendar.MONTH, month); int day = c.getActualMaximum(c.DAY_OF_MONTH); c.set(Calendar.DAY_OF_MONTH, day); return c.getTime(); } }?