JAVA 十分实用的日期工具类
JAVA 非常实用的日期工具类
import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.Date; public class DateUtils extends org.apache.commons.lang.time.DateUtils { /** * 格式化 * * @param date * @param format * @return String */ public static String parseDate(Date date, String parsePatterns) { SimpleDateFormat sdf = new SimpleDateFormat(parsePatterns); return sdf.format(date); } /** * 默认格式化(yyyy-MM-dd HH:mm:ss) * * @param date * @return String */ public static String parseDate(Date date) { SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); return sdf.format(date); } /** * 默认格式化(yyyy-MM-dd HH:mm:ss) * * @param str * @return * @throws ParseException */ public static Date parseDate(String str) throws ParseException { return DateUtils.parseDate(str, new String[] { "yyyy-MM-dd HH:mm:ss" }); } /** * 得到某个月的第一天 * * @param date * @return Date */ public static Date getFirstDayOfMonth(Date date) throws ParseException { String strdate = DateUtils.parseDate(date, "yyyy-MM-01 00:00:00"); return DateUtils.parseDate(strdate); } public static int getDayOfWeek() throws ParseException { Calendar c = Calendar.getInstance(); int dayForWeek = 0; if(c.get(Calendar.DAY_OF_WEEK) == 1){ dayForWeek = 7; }else{ dayForWeek = c.get(Calendar.DAY_OF_WEEK) - 1; } return dayForWeek; } public static String getWeekOfDate(Date date,int tag) { String[] weekDaysName = { "星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六" }; String[] weekDaysCode = { "7", "1", "2", "3", "4", "5", "6" }; Calendar calendar = Calendar.getInstance(); calendar.setTime(date); int intWeek = calendar.get(Calendar.DAY_OF_WEEK) - 1; if( tag == 0 ){ return weekDaysName[intWeek]; }else{ return weekDaysCode[intWeek]; } } }