JAVA时间格式处理工具类

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

public class DateUtil {

/** * 默认日期格式 */ public static String DEFAULT_FORMAT = "yyyy-MM-dd"; private static final SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd"); private static final SimpleDateFormat formatMs = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.sss"); /** * 格式化日期 * @param date 日期对象 * @return String 日期字符串 */ public static String formatDate(Date date){ SimpleDateFormat f = new SimpleDateFormat(DEFAULT_FORMAT); String sDate = f.format(date); return sDate; } /** * 格式化日期 * @param str 日期对象 * @return String 日期字符串 */ public static Date formatDate(String str){ Date date = null; try{ SimpleDateFormat f = new SimpleDateFormat(DEFAULT_FORMAT); date = f.parse(str); }catch (Exception e){ e.printStackTrace(); } return date; } /** * 获取某年第一天日期 * @param date 账期 * @return Date */ public static String getYearFirst(String date){ Calendar calendar = Calendar.getInstance(); calendar.clear(); calendar.set(Calendar.YEAR, Integer.parseInt(date.substring(0, 4))); Date currYearFirst = calendar.getTime(); return formatDate(currYearFirst); } /** * 获取上年第一天日期 * @param date 账期 * @return Date */ public static String getLastYearFirst(String date){ Calendar calendar = Calendar.getInstance(); calendar.clear(); calendar.set(Calendar.YEAR, Integer.parseInt(date.substring(0, 4))); calendar.add(Calendar.YEAR, -1); Date currYearFirst = calendar.getTime(); return formatDate(currYearFirst); } /** * 获取某日的前一天日期 * @return Date */ public Date getDaysBefore(String dateString, int days) throws ParseException { DateFormat dateFormat = new SimpleDateFormat("yyyyMMdd"); Date inputDate = dateFormat.parse(dateString); Calendar cal = Calendar.getInstance(); cal.setTime(inputDate); int dayOfYear = cal.get(Calendar.DAY_OF_YEAR); cal.set(Calendar.DAY_OF_YEAR, dayOfYear - days); return cal.getTime(); } /** * 获取某月上一个月份 * @return Date */ public Date getMonthsBefore(String dateString, int months) throws ParseException { DateFormat dateFormat = new SimpleDateFormat("yyyyMMdd"); Date inputDate = dateFormat.parse(dateString); Calendar cal = Calendar.getInstance(); cal.setTime(inputDate); int monthOfYear = cal.get(Calendar.MONTH); cal.set(Calendar.MONTH, monthOfYear - months); return cal.getTime(); } /** * 获取某月第一天日期 * @return Date */ public Date getFisrtDayOfMonth(String dateString) throws ParseException { DateFormat dateFormat = new SimpleDateFormat("yyyyMM"); Date inputDate = dateFormat.parse(dateString); Calendar cal = Calendar.getInstance(); cal.setTime(inputDate); int firstDay = cal.getActualMinimum(Calendar.DAY_OF_MONTH); cal.set(Calendar.DAY_OF_MONTH, firstDay); return cal.getTime(); } /** * 获取某月最后一天日期 * @return Date */ public Date getLastDayOfMonth(String dateString) throws ParseException { DateFormat dateFormat = new SimpleDateFormat("yyyyMM"); Date inputDate = dateFormat.parse(dateString); Calendar cal = Calendar.getInstance(); cal.setTime(inputDate); int lastDay = cal.getActualMaximum(Calendar.DAY_OF_MONTH); cal.set(Calendar.DAY_OF_MONTH, lastDay); return cal.getTime(); } /** * 获取最后一个月的第一天日期 * @return Date */ public static String getLastMonthFirstDay() { Calendar cal_1 = Calendar.getInstance(); cal_1.add(Calendar.MONTH, -1); cal_1.set(Calendar.DAY_OF_MONTH, 1); String firstDay = format.format(cal_1.getTime()); System.out.println("-----1------firstDay:" + firstDay); return firstDay; } /** * 获取最后一个月最后一天日期 * @return Date */ public static String getLastMonthlastDay() { Calendar cale = Calendar.getInstance(); cale.set(Calendar.DAY_OF_MONTH, 0); String lastDay = format.format(cale.getTime()); System.out.println("-----2------lastDay:" + lastDay); return lastDay; } /** * 获取当前月第一天日期 * @return Date */ public static String getCurrentMonthFirstDay() { Calendar c = Calendar.getInstance(); c.add(Calendar.MONTH, 0); c.set(Calendar.DAY_OF_MONTH, 1); String first = format.format(c.getTime()); System.out.println("===============first:" + first); return first; } /** * 获取当前月最后一天日期 * @return Date */ public static String getCurrentMonthlastDay() { Calendar ca = Calendar.getInstance(); ca.set(Calendar.DAY_OF_MONTH, ca.getActualMaximum(Calendar.DAY_OF_MONTH)); String last = format.format(ca.getTime()); System.out.println("===============last:" + last); return last; } /** * 获取当前年份第一天日期 * @return Date */ public static Date getCurrYearFirst() { Calendar currCal = Calendar.getInstance(); int currentYear = currCal.get(Calendar.YEAR); return getYearFirst(currentYear); } /** * 根据传入的参数获取该年的第一天 * @return Date */ public static Date getCurrYearFirst(String dateString) throws ParseException { DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd"); Date inputDate = dateFormat.parse(dateString); Calendar cal = Calendar.getInstance(); cal.setTime(inputDate); int currentYear = cal.get(Calendar.YEAR); return getYearFirst(currentYear); } /** * 根据传入的参数获取该年月 * @return Date */ public static String getMonth(String dateString) throws ParseException { DateFormat dateFormat = new SimpleDateFormat("MM"); Date inputDate = dateFormat.parse(dateString); Calendar cal = Calendar.getInstance(); cal.setTime(inputDate); return formatDate(cal.getTime()); } /** * 获取当前年份最后一天 * @return Date */ public static Date getCurrYearLast() { Calendar currCal = Calendar.getInstance(); int currentYear = currCal.get(Calendar.YEAR); return getYearLast(currentYear); } /** * 根据传入的参数获取该年 * @return Date */ public static Date getYearFirst(int year) { Calendar calendar = Calendar.getInstance(); calendar.clear(); calendar.set(Calendar.YEAR, year); Date currYearFirst = calendar.getTime(); return currYearFirst; } /** * 根据传入的参数获取该年 * @return Date */ public static Date getYearLast(int year) { Calendar calendar = Calendar.getInstance(); calendar.clear(); calendar.set(Calendar.YEAR, year); calendar.roll(Calendar.DAY_OF_YEAR, -1); Date currYearLast = calendar.getTime(); return currYearLast; } /** * 根据传入的参数获取该年月 * @return Date */ public static String getCurrentYear(){ SimpleDateFormat sdf = new SimpleDateFormat("yyyy"); Date date = new Date(); return sdf.format(date);} /** * 根据传入的参数获取该年月 * @return Date */ public static String getLastYear() { Calendar date = Calendar.getInstance(); date.add(Calendar.YEAR, -1); String year = String.valueOf(date.get(Calendar.YEAR)); return year; } /** * 现在时间+6个月与next_time比较 * @return */ public static String getStaleDated(){ SimpleDateFormat sdfTimeStamp = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.sss"); Date date= new Date(); Calendar cd = Calendar.getInstance(); cd.setTime(date); cd.add(Calendar.MONTH, 6); date=cd.getTime(); String stale_dated = sdfTimeStamp.format(date); return stale_dated; } /** * 获取当前时间 * @return */ public static String currentDatetime(){ SimpleDateFormat tempDate = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String datetime = tempDate.format(new java.util.Date()); return datetime; } /** * 获取当前时间 * * @return */ public static String getYyMmtime() { SimpleDateFormat tempDate = new SimpleDateFormat("yyyy-MM"); String datetime = tempDate.format(new java.util.Date()); return datetime; } /** * 日期计算 * @param date * @param type * @param number * @return */ public static String calculateDate(String date,String type,int number){ try{

// SimpleDateFormat sdfTimeStamp = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.sss");

 SimpleDateFormat sdfTimeStamp = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); //String create_time = sdfTimeStamp.format(new Date()); Date tmpDate = sdfTimeStamp.parse(date); Calendar cd = Calendar.getInstance(); cd.setTime(tmpDate); if(type.equals("m")){ cd.add(Calendar.MONTH, number); }else if (type.equals("d")){ cd.add(Calendar.DAY_OF_MONTH, number); }else { return "type is unknown"; } tmpDate = cd.getTime(); String dateRuslt = sdfTimeStamp.format(tmpDate); return dateRuslt; }catch(Exception ex){ return "calculate failed"; } } public static Date getDateByStr(String string){ //String string = "2016-10-24 21:59:06"; SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); Date date =null; try{ date = sdf.parse(string); System.out.println(sdf.parse(string)); }catch (Exception e){ e.printStackTrace(); } return date; } public static String getStrByDate(Date date) { //String string = "2016-10-24 21:59:06"; SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String dateTime = null; try { dateTime = sdf.format(date); } catch (Exception e) { e.printStackTrace(); } return dateTime; } 

public static String getUpdateTime(){ //当前时间重写更新时间 SimpleDateFormat sdfTimeStamp = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.sss"); String update_time = sdfTimeStamp.format(new Date()); return update_time; } 

public static void main(String[] args) throws ParseException { DateUtil dateTest = new DateUtil(); // DateFormat df = new SimpleDateFormat("yyyyMMdd"); // Date before7Day = dateTest.getDaysBefore("20140301", 7); // System.out.println(df.format(before7Day)); // Date testFirstDay = dateTest.getLastDayOfMonth("201407"); // System.out.println(df.format(testFirstDay)); // Date testBeforeMonth = dateTest.getMonthsBefore("20140712", 12); // System.out.println(df.format(testBeforeMonth)); // DateFormat df2 = new SimpleDateFormat("yyyyMM"); // Date getFisrtDayOfMonth = dateTest.getFisrtDayOfMonth("201407"); // System.out.println(df2.format(getFisrtDayOfMonth)); System.out.println(getStaleDated());

// System.out.println(formatDate(getCurrYearLast()));
// String stObj="2016-3-21";
// String[] timeDay = stObj.split("-");
// System.out.println(timeDay[1]);

}

}