Java 日期工具类
jopen
10年前
import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.Date; /** * 时间处理工具类 <br> * * @author Davint * @since 5.0 * @version 1.0 */ public class TimerUtil { private SimpleDateFormat sp = new SimpleDateFormat("yyyy-MM-dd"); private static TimerUtil cc = new TimerUtil(); public static TimerUtil getInstance() { return cc; } public static void main(String[] args) { TimerUtil timer=TimerUtil.getInstance(); System.out.println(timer.getDaysByDate(timer.getDate("2012-04-01", "yyyy-MM-dd"))); } //根据日期得到当月天数 public int getDaysByDate(Date date) { Calendar ca=Calendar.getInstance(); ca.setTime(date); int year=ca.get(Calendar.YEAR); int month=ca.get(Calendar.MONDAY)+1; int day=0; if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) { if (month==2) { day=29; } }else { if (month==2) { day=28; } } if (month==4||month==6||month==9||month==11) { day=30; } if (month==1||month==3||month==5||month==7||month==8||month==10||month==12) { day=31; } return day; } /** * 上周一的日期 * 将周一作为一周的第一天 */ public Date getLastWeekFirstDay() { Calendar ca = Calendar.getInstance(); if (ca.get(Calendar.DAY_OF_WEEK)-1==0) { ca.add(Calendar.DATE, -1 * 7*2); ca.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY); return ca.getTime(); } ca.add(Calendar.DATE, -1 * 7); ca.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY); return ca.getTime(); } // 本周一日期 public Date getThisWeekFirstDay() { Calendar ca=Calendar.getInstance(); if (ca.get(Calendar.DAY_OF_WEEK)-1==0) { ca.add(Calendar.DATE, -1); ca.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY); return ca.getTime(); } ca.add(Calendar.DATE, 0); ca.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY); return ca.getTime(); } //两个月前的第一天 public Date getLast2MonFirstDay() { Calendar cal=Calendar.getInstance(); Date now=new Date(); cal.setTime(now); cal.add(Calendar.MONTH, -1); int year=cal.get(Calendar.YEAR); int month=cal.get(Calendar.MONTH); String resultTime=year+"-"+month+"-01"; Date date =null; try { date=sp.parse(resultTime); } catch (ParseException e) { e.printStackTrace(); } return date; } // 上个月第一天日期 public Date getLastMonFirstDay() { Calendar cal=Calendar.getInstance(); Date now=new Date(); cal.setTime(now); int year=cal.get(Calendar.YEAR); int month=cal.get(Calendar.MONTH); String resultTime=year+"-"+month+"-01"; Date date =null; try { date=sp.parse(resultTime); } catch (ParseException e) { e.printStackTrace(); } return date; } // 本月第一天 public Date getThisMonFirstDay() { Calendar cal = Calendar.getInstance(); int year = cal.get(Calendar.YEAR); int month = cal.get(Calendar.MONTH) + 2; cal.set(Calendar.DAY_OF_MONTH, 1); cal.add(Calendar.DAY_OF_MONTH, -1); int day = cal.get(Calendar.DAY_OF_MONTH); String months = ""; String days = ""; if (month > 1) { month--; } else { year--; month = 12; } if (!(String.valueOf(month).length() > 1)) { months = "0" + month; } else { months = String.valueOf(month); } if (!(String.valueOf(day).length() > 1)) { days = "0" + day; } else { days = String.valueOf(day); } String firstDay = "" + year + "-" + months + "-01"; String[] lastMonth = new String[2]; lastMonth[0] = firstDay; try { return sp.parse(firstDay); } catch (ParseException e) { } return null; } // 昨天日期 public String getYesterday() { Date today = new Date(); Calendar ca = Calendar.getInstance(); ca.setTime(today); ca.add(Calendar.DAY_OF_YEAR, -1); return sp.format(ca.getTime()); } // 7天前日期 public String getSevenDayAgo() { Date today = new Date(); Calendar ca = Calendar.getInstance(); ca.setTime(today); ca.add(Calendar.DAY_OF_YEAR, -7); return sp.format(ca.getTime()); } // 3天前日期 public String getThreeDayAgo() { Date today = new Date(); Calendar ca = Calendar.getInstance(); ca.setTime(today); ca.add(Calendar.DAY_OF_YEAR, -3); return sp.format(ca.getTime()); } // 一月前日期 public String getOneMonthAgo() { Calendar cal = Calendar.getInstance(); cal.add(Calendar.MONTH, -1); // 得到前一个月 long date = cal.getTimeInMillis(); Date kk = new Date(date); return sp.format(kk); } // 3月前日期 public String getThreeMonthAgo() { Calendar cal = Calendar.getInstance(); cal.add(Calendar.MONTH, -3); long date = cal.getTimeInMillis(); Date kk = new Date(date); return sp.format(kk); } /** * getDate<br> * 格式：yyyy-MM-dd 00:00:00 eg.2013-08-19 00:00:00<br> * @param type -1表示昨天；-2表示前天；以此类推-N表示前N天 * @return java.util.Date */ public Date getDate(int type) { Date resultDate = null; Date today = new Date(); Calendar ca = Calendar.getInstance(); ca.setTime(today); ca.add(Calendar.DAY_OF_YEAR, type); // 将时间转换成00:00:00 try { resultDate = sp.parse(sp.format(ca.getTime())); return resultDate; } catch (ParseException e) { e.printStackTrace(); } return resultDate; } /** * N天前的具体时间 * * @param n 0 表示今天，-1代表昨天 * @param type yyyyMMddHHmmss、yyyy-MM-dd HH:mm:ss * @return */ public String getSomeDaysAgoString(int n, String type) { Date today = new Date(); SimpleDateFormat sp = new SimpleDateFormat(); sp.applyPattern(type); Calendar ca = Calendar.getInstance(); ca.setTime(today); ca.add(Calendar.DAY_OF_YEAR, n); return sp.format(ca.getTime()); } /** * N天前的具体时间 * * @param n 0 表示今天，-1代表昨天 * @return */ public Date getSomeDaysAgoDate(int n) { Date today = new Date(); Calendar ca = Calendar.getInstance(); ca.setTime(today); ca.add(Calendar.DAY_OF_YEAR, n); return ca.getTime(); } /** * 格式化某一时间 * * @param date * @param type * @return */ public String getString(Date date, String type) { SimpleDateFormat sp = new SimpleDateFormat(); sp.applyPattern(type); if (date != null && type != null) { return sp.format(date); } return "时间格式化异常！"; } /** * 格式化某一时间字符串 * * @param date * @param type * @return */ public Date getDate(String date, String type) { SimpleDateFormat sp = new SimpleDateFormat(); sp.applyPattern(type); try { if (date != null && type != null) { return sp.parse(date); } return null; } catch (ParseException e) { e.printStackTrace(); } return null; } /** * 某日期前、后N天的日期 * @param date 某一日期 * @param type N天 0表示当天，N或+N表示后N天的日期，-N表示前N天的日期 * @return java.util.Date */ public Date getDate(Date date,int type) { Calendar cal=Calendar.getInstance(); cal.setTime(date); cal.add(Calendar.DAY_OF_YEAR, type); return cal.getTime(); } }