Java Date 日期 时间 相关方法

DateTools.java

import java.text.SimpleDateFormat;
import java.util.Date;
/**
 * 日期操作类
 */
public class DateTools {
    /**yyyyMMddHHmmss
     * 
     * @return
     */
    public static String getAllDate(){
        SimpleDateFormat   lFormat; 
          //格式可以自己根据需要修改   
        lFormat   =     new   SimpleDateFormat("yyyyMMddHHmmss");   
        String   gRtnStr   =   lFormat.format(new Date()); 
        return gRtnStr;
    }
    /**
     * 获得yymmdd类型的日期
     * @param date
     * @return
     */
    public static String getDateString(Date date){
        String year =(date.getYear()+1900)+"";
        String mm = (date.getMonth()+1)+"";
        if(Integer.valueOf(mm).intValue()<10){
            mm="0"+mm;
        }
        String day = date.getDate()+"";
        if(Integer.valueOf(day).intValue()<10)day="0"+day;
        return year+mm+day;
    }
    /**
     * 获得yymmdd类型的日期(日期的前1天)
     * @param date
     * @return
     */
    public static String getZDateString(Date date){
        date.setDate(date.getDate()-1);
        String year =(date.getYear()+1900)+"";
        String mm = (date.getMonth()+1)+"";
        if(Integer.valueOf(mm).intValue()<10){
            mm="0"+mm;
        }
        String day = date.getDate()+"";
        if(day.length()==1)day="0"+day;
        return year+mm+day;
    }
    /**
     * 获得yy-mm-dd类型的日期
     * @param date
     * @return
     */
    public  static String DateString(Date date){
        String year =(date.getYear()+1900)+"";
        String mm = (date.getMonth()+1)+"";
        if(Integer.valueOf(mm).intValue()<10){
            mm="0"+mm;
        }
        String day = date.getDate()+"";
        if(day.length()==1){
            day="0"+day;
        }
        return year+"-"+mm+"-"+day;
    }
     //得到当前时间
    public static String getCurrentDateTime() {
        java.text.SimpleDateFormat d = new java.text.SimpleDateFormat();
        d.applyPattern("HH:mm:ss");
        java.util.Date nowdate = new java.util.Date();
        String str_date = d.format(nowdate);
        return str_date;
    }
    /**
     * 时间格式化
     * @return
     */
    public static String getTimeString(String time){
        String[] ti = time.split(":");
        if(ti[1].length()==1){
            time = ti[0]+"0"+ti[1];
        }else{
            time = ti[0]+ti[1];
        }
        return time;
    }
    public static String TimeString(){
        Date date = new Date();
        return getTimeString(date.getHours()+":"+date.getMinutes());
    }
    public static void main(String args[]){
        System.out.println(DateTools.getZDateString(new Date()));
        
    }
}

DateTime.java

import java.util.*;
import java.text.*;

public class DateTime {

    public DateTime() {
    }

    public static final long SECOND = 1000;

    public static final long MINUTE = 60 * SECOND;

    public static final long HOUR = 60 * MINUTE;

    public static final long DAY = 24 * HOUR;

    public static final long WEEK = 7 * DAY;

    public static final String SHORTFORMAT = "yyyy-MM-dd";

    public static final String SHORTFORMATNOSPIT = "yyyyMMdd";

    public static final String YEARMONTHFORMAT = "yyyy-MM";

    public static final String LONGFORMAT = "yyyy-MM-dd HH:mm:ss";
    /**
     * 获得yymmdd类型的日期
     * @param date
     * @return
     */
    public static String getDateString(Date date){
        String year =(date.getYear()+1900)+"";
        String mm = (date.getMonth()+1)+"";
        if(Integer.valueOf(mm).intValue()<10){
            mm="0"+mm;
        }
        String day = date.getDate()+"";
        return year+mm+day;
    }
    /**
     * 获得yy-mm-dd类型的日期
     * @param date
     * @return
     */
    public  static String DateString(Date date){
        String year =(date.getYear()+1900)+"";
        String mm = (date.getMonth()+1)+"";
        if(Integer.valueOf(mm).intValue()<10){
            mm="0"+mm;
        }
        String day = date.getDate()+"";
        if(day.length()==1){
            day="0"+day;
        }
        return year+"-"+mm+"-"+day;
    }


     // 得到某一天是星期几
    public static int getDateInWeek(String strDate) {
        DateFormat df = DateFormat.getDateInstance();
        try {
            df.parse(strDate);
            java.util.Calendar c = df.getCalendar();
            int day = c.get(Calendar.DAY_OF_WEEK) - Calendar.SUNDAY;
            return day;
        } catch (ParseException e) {
            return -1;
        }
    }

    
     //得到当前日期

    public static String getCurrentDate() {
        java.text.SimpleDateFormat d = new java.text.SimpleDateFormat();
        d.applyPattern("yyyy-MM-dd");
        java.util.Date nowdate = new java.util.Date();
        String str_date = d.format(nowdate);
        return str_date;
    }
    
     //得到当前日期时间
    public static String getCurrentDateTime() {
        java.text.SimpleDateFormat d = new java.text.SimpleDateFormat();
        d.applyPattern("yyyy-MM-dd HH:mm:ss");
        java.util.Date nowdate = new java.util.Date();
        String str_date = d.format(nowdate);
        return str_date;

    }
    //根据日期获得日期时间
    public static String getDateTime(java.util.Date date) {
        java.text.SimpleDateFormat d = new java.text.SimpleDateFormat();
        d.applyPattern("yyyy-MM-dd HH:mm:ss");
        String str_date = d.format(date);
        return str_date;
    }
    //获得某月的最后一天
    public static int getDayNum(int year, int month) {
        if (month == 2) {
            return year % 400 != 0 && (year % 4 != 0 || year % 100 == 0) ? 28
                    : 29;
        }
        String SmallMonth = ",4,6,9,11,";
        return SmallMonth.indexOf(String.valueOf(String
                .valueOf((new StringBuffer(",")).append(String.valueOf(month))
                        .append(",")))) < 0 ? 31 : 30;
    }

      //返回两个日期之间隔了多少天

      public static int DateDiff(Date date1, Date date2) {
        int i = (int) ( (date1.getTime() - date2.getTime()) / 3600 / 24 / 1000);
        return i;
      }


     //从放有日期的字符串中得到，相应的年，月，日 style is "Y"or"y" 返回年 style is "M"or"m" 返回月 style
     //is "D"or"d" 返回日 日期字符串要求 "YYYY-MM-DD"
    public static int getYearMonthDate(String strDate, String style) {
        int year;
        int month;
        int day;
        int firstDash;
        int secondDash;
        if (strDate == null) {
            return 0;
        }
        firstDash = strDate.indexOf('-');
        secondDash = strDate.indexOf('-', firstDash + 1);
        if ((firstDash > 0) & (secondDash > 0)
                & (secondDash < strDate.length() - 1)) {
            year = Integer.parseInt(strDate.substring(0, firstDash));
            month = Integer.parseInt(strDate.substring(firstDash + 1,
                    secondDash));
            day = Integer.parseInt(strDate.substring(secondDash + 1));
        } else {
            return 0;
        }
        if (style.equalsIgnoreCase("Y")) {
            return year;
        } else if (style.equalsIgnoreCase("M")) {
            return month;
        } else if (style.equalsIgnoreCase("D")) {
            return day;
        } else {
            return 0;
        }
    }
     // 某一天，过几天后是几号

      public static java.sql.Date DateAdd(java.sql.Date date, int addday) {
        java.sql.Date datenew = null;
        int year = DateTime.getYearMonthDate(date.toString(), "Y");
        int month = DateTime.getYearMonthDate(date.toString(), "M");
        int day = DateTime.getYearMonthDate(date.toString(), "D");
        day = day + addday;
        String dayStr = Integer.toString(year) + "-" + Integer.toString(month) +
            "-" + Integer.toString(day);
        datenew = datenew.valueOf(dayStr);
        //datenew.setTime(datenew.getTime()+day*3600*24*1000);
        //有问题。 改
        return datenew;

      }

    //某一天的前几天是几号

    public static java.sql.Date DateBefore(java.sql.Date date, int addday) {
        java.sql.Date datenew = null;
        int year = DateTime.getYearMonthDate(date.toString(), "Y");
        int month = DateTime.getYearMonthDate(date.toString(), "M");
        int day = DateTime.getYearMonthDate(date.toString(), "D");
        day = day - addday;
        String dayStr = Integer.toString(year) + "-" + Integer.toString(month)
                + "-" + Integer.toString(day);
        datenew = datenew.valueOf(dayStr);
        // datenew.setTime(datenew.getTime()+day*3600*24*1000);
        // 有问题。 改
        return datenew;
    }



    //某一天是否是年的头一天

    public static boolean isYearFirstDay(java.sql.Date date) {
        boolean i = false;
        if ((DateTime.getYearMonthDate(date.toString(), "M") == 1)
                && (DateTime.getYearMonthDate(date.toString(), "D") == 1)) {
            i = true;
        }
        return i;
    }

    // 某一天是否是半年的头一天

    public static boolean isHalfYearFirstDay(java.sql.Date date) {
        boolean i = false;
        if (((DateTime.getYearMonthDate(date.toString(), "M") == 1) && (DateTime
                .getYearMonthDate(date.toString(), "D") == 1))
                || ((DateTime.getYearMonthDate(date.toString(), "M") == 7) && (DateTime
                        .getYearMonthDate(date.toString(), "D") == 1))) {
            i = true;
        }
        return i;
    }

    public static String getHalfYearFirstDay(java.sql.Date date) {
        String month = "01";
        if (DateTime.getYearMonthDate(date.toString(), "M") >= 7) {
            month = "07";
        }
        String day = Integer.toString(DateTime.getYearMonthDate(date
                .toString(), "Y"))
                + "-" + month + "-01";
        return day;
    }

    // 某一天是否是半年的最后一天

    public static boolean isHalfYearLastDay(java.sql.Date date) {
        boolean i = false;
        if (((DateTime.getYearMonthDate(date.toString(), "M") == 12) && (DateTime
                .getYearMonthDate(date.toString(), "D") == 31))
                || ((DateTime.getYearMonthDate(date.toString(), "M") == 6) && (DateTime
                        .getYearMonthDate(date.toString(), "D") == 30))) {
            i = true;
        }
        return i;
    }

    public static String getHalfYearLastDay(java.sql.Date date) {
        String month = "-06-30";
        if (DateTime.getYearMonthDate(date.toString(), "M") >= 7) {
            month = "-12-31";
        }
        String day = Integer.toString(getYearMonthDate(date.toString(), "Y"))
                + "-" + month;
        return day;
    }

    // 某一天是否是年的最后一天

    public static boolean isYearLastDay(java.sql.Date date) {
        boolean i = false;
        if ((DateTime.getYearMonthDate(date.toString(), "M") == 12)
                && (DateTime.getYearMonthDate(date.toString(), "D") == 31)) {
            i = true;
        }
        return i;
    }

    //某一天是否是季的头一天
    

    public static boolean isQuarterFirstDay(java.sql.Date date) {
        boolean i = false;
        if (((DateTime.getYearMonthDate(date.toString(), "M") == 1)
                || (DateTime.getYearMonthDate(date.toString(), "M") == 4)
                || (DateTime.getYearMonthDate(date.toString(), "M") == 7) || (DateTime
                .getYearMonthDate(date.toString(), "M") == 10))
                && (DateTime.getYearMonthDate(date.toString(), "D") == 1)) {
            i = true;
        }
        return i;
    }

    public static String getQuarterFirstDay(java.sql.Date date) {
        String month = "01";
        if (DateTime.getYearMonthDate(date.toString(), "M") >= 10) {
            month = "10";
        } else if (DateTime.getYearMonthDate(date.toString(), "M") >= 7) {
            month = "07";
        } else if (DateTime.getYearMonthDate(date.toString(), "M") >= 4) {
            month = "04";
        } else if (DateTime.getYearMonthDate(date.toString(), "M") >= 1) {
            month = "01";
        }

        String day = Integer.toString(DateTime.getYearMonthDate(date
                .toString(), "Y"))
                + "-" + month + "-01";
        return day;
    }

    //某一天是否是季的最后一天

    public static boolean isQuarterLastDay(java.sql.Date date) {
        boolean i = false;
        if ((DateTime.getYearMonthDate(date.toString(), "M") == 3)
                && (DateTime.getYearMonthDate(date.toString(), "D") == 31)) {
            i = true;
        }
        if ((DateTime.getYearMonthDate(date.toString(), "M") == 6)
                && (DateTime.getYearMonthDate(date.toString(), "D") == 30)) {
            i = true;
        }
        if ((DateTime.getYearMonthDate(date.toString(), "M") == 9)
                && (DateTime.getYearMonthDate(date.toString(), "D") == 30)) {
            i = true;
        }
        if ((DateTime.getYearMonthDate(date.toString(), "M") == 12)
                && (DateTime.getYearMonthDate(date.toString(), "D") == 31)) {
            i = true;
        }
        return i;
    }

    public static String getQuarterLastDay(java.sql.Date date) {
        String month = "-01-31";
        if (DateTime.getYearMonthDate(date.toString(), "M") >= 10) {
            month = "-12-31";
        } else if (DateTime.getYearMonthDate(date.toString(), "M") >= 7) {
            month = "-09-30";
        } else if (DateTime.getYearMonthDate(date.toString(), "M") >= 4) {
            month = "-06-30";
        }

        String day = Integer.toString(DateTime.getYearMonthDate(date
                .toString(), "Y"))
                + "-" + month;
        return day;
    }
     //某一天是否是月的最后一天


    public static boolean isMonthLastDay(java.sql.Date date) {
        boolean i = false;
        java.sql.Date des_date = null;
        String month;
        String str_date = date.toString();
        String year = str_date.substring(0, str_date.indexOf("-"));
        int m = new Integer(str_date.substring(str_date.indexOf("-") + 1,
                str_date.lastIndexOf("-"))).intValue() + 1;
        month = new Integer(m).toString();
        if (m < 10) {
            month = "0" + month;
        }
        java.sql.Date mid_date = null;
        mid_date = mid_date.valueOf(year + "-" + month + "-01");
        des_date = DateTime.DateAdd(mid_date, -1);
        if (DateTime.DateDiff(des_date, date) == 0) {
            i = true;
        }
        return i;
    }

    //某一天是否是月的第一天


    public static boolean isMonthFisrtDay(java.sql.Date date) {
        boolean i = false;
        if ((DateTime.getYearMonthDate(date.toString(), "D") == 1)) {
            i = true;
        }
        return i;
    }
    //获得月的第一天
    public static String getMonthFisrtDay(java.sql.Date date)

    {
        String month;
        if (DateTime.getYearMonthDate(date.toString(), "M") > 9) {
            month = Integer.toString(DateTime.getYearMonthDate(date
                    .toString(), "M"));
        } else {
            month = "0"
                    + Integer.toString(DateTime.getYearMonthDate(date
                            .toString(), "M"));
        }
        String day = Integer.toString(DateTime.getYearMonthDate(date
                .toString(), "Y"))
                + "-" + month + "-01";
        return day;
    }

    public static java.sql.Timestamp getTimestamp() {
        try {
            java.text.SimpleDateFormat myFormat = new SimpleDateFormat(
                    "yyyy-MM-dd HH:mm:ss");
            java.util.Calendar calendar = java.util.Calendar.getInstance();
            String mystrdate = myFormat.format(calendar.getTime());
            return java.sql.Timestamp.valueOf(mystrdate);
        } catch (Exception e) {
            return null;
        }
    }

    public static java.sql.Timestamp getTimestamp(String datestr) {
        try {
            java.text.SimpleDateFormat myFormat = new SimpleDateFormat(
                    "yyyy-MM-dd HH:mm:ss");
            String mystrdate = myFormat.format(myFormat.parse(datestr));
            return java.sql.Timestamp.valueOf(mystrdate);
        } catch (Exception e) {
            return null;
        }
    }
     //格式化日期（Y-年，M-月,D-日 HH:mm:ss 小时：分钟：秒）
    public static String getDate(java.util.Date date, String format) {
        String result = null;
        try {
            java.text.SimpleDateFormat myFormat = new SimpleDateFormat(format);
            result = myFormat.format(date);
        } catch (Exception e) {
            return null;
        }
        return result;
    }

    public static String getDate(java.util.Date date) {
        return getDate(date, LONGFORMAT);
    }
    //转换成时间戳
    public static java.sql.Timestamp getDate(String datestr) {
        try {
            java.text.SimpleDateFormat myFormat = new SimpleDateFormat(
                    "yyyy-MM-dd");
            Date date = myFormat.parse(datestr);
            myFormat.applyLocalizedPattern("yyyy-MM-dd HH:mm:ss");
            String mystrdate = myFormat.format(date);
            return java.sql.Timestamp.valueOf(mystrdate);
        } catch (Exception e) {
            return null;
        }
    }
    //将日期格式化成yyyy-MM-dd形式
    public static java.util.Date format(String datestr) {
        try {
            java.text.SimpleDateFormat myFormat = new SimpleDateFormat(
                    "yyyy-MM-dd");
            Date date = myFormat.parse(datestr);
            return date;
        } catch (Exception e) {
            return new Date(datestr);
        }
    }
    //格式化日期（Y-年，M-月,D-日 HH:mm:ss 小时：分钟：秒）
    public static java.util.Date format(String datestr, String format) {
        try {
            java.text.SimpleDateFormat myFormat = new SimpleDateFormat(format);
            Date date = myFormat.parse(datestr);
            return date;
        } catch (Exception e) {
            return null;
        }
    }

    //获得数据库格式的日期
    public static java.sql.Date getSqlDate(java.util.Date date) {
        java.sql.Date result = null;
        try {
            java.text.SimpleDateFormat myFormat = new SimpleDateFormat(
                    "yyyy-MM-dd");
            String mystrdate = myFormat.format(date);
            result = java.sql.Date.valueOf(mystrdate);
        } catch (Exception e) {
            return null;
        }
        return result;
    }
    
    public static java.util.Date addMonth(java.util.Date date, int month) {
        String strdate = getDate(date, SHORTFORMAT);
        int curmonth = Integer.parseInt(strdate.substring(5, 7));
        int year = Integer.parseInt(strdate.substring(0, 4));
        int addyear = month / 12;
        year = year + addyear;
        curmonth = curmonth + (month % 12);
        if (curmonth > 12) {
            curmonth = 1;
            year = year + 1;
        }
        String strmonth = String.valueOf(curmonth);
        if (strmonth.length() == 1) {
            strmonth = "0" + strmonth;
        }
        strdate = String.valueOf(year) + "-" + strmonth + "-"
                + strdate.substring(8, 10);
        return format(strdate, SHORTFORMAT);
    }
    
    /**
     * 传递日期，  获得上个月的最后1天
     * @param dt
     * @return
     */
    public static String getUpMDate(Date dt){
        dt.setDate(1);
        dt.setDate(dt.getDate()-1);
        return dt.toLocaleString();
    }
     /**
       *得到当前是那一天。
       *
       */
      public static String getDate() {
           java.text.SimpleDateFormat d = new java.text.SimpleDateFormat();
            d.applyPattern("yyyy-MM-dd");
        java.util.Date nowdate = new java.util.Date();
        String str_date = d.format(nowdate);
        return str_date;
      }
    
    /**
     * 将10位日期格式化为8位
     * @param dt
     * @return
     */
    public static String getShortDate(String dt){
        if(dt != null){
            java.text.SimpleDateFormat myFormat = new SimpleDateFormat("yyyy-MM-dd");
            try {
                Date date = myFormat.parse(dt);
                return getDate(date,SHORTFORMATNOSPIT);
            } catch (ParseException e) {
                return dt;
            }
        }else
            return dt;
    }
    
    /**
     * 将8位日期格式化为10位
     * @param dt
     * @return
     */
    public static String getLongDate(String dt){
        if(dt != null){
            java.text.SimpleDateFormat myFormat = new SimpleDateFormat("yyyyMMdd");
            try {
                Date date = myFormat.parse(dt);
                return getDate(date,SHORTFORMAT);
            } catch (ParseException e) {
                return dt;
            }
        }else
            return dt;
    }
    
    /**
     * 判断是否是当月
     * @param month
     * @return
     */
    public static boolean isSameYearMonth(String date){
        try{
            String currdate = getCurrentDate();
            currdate = getShortDate(currdate).substring(0,6);
            String lastdate = getShortDate(date).substring(0,6);
            if(lastdate.equals(currdate)){
                return true;
            }else{
                return false;
            }
        }catch(NumberFormatException e){
            return false;
        }
    }
    
     
      public static void main(String[] args){
          Date d = new Date("20070829");
          Date f = new Date("20070912");
          
          System.out.println(d.getDate()-f.getDate());
      }
}

   这几天一直在处理Java的日期问题，通常需要按要求生成日期的话，通常会用到util包中的Calendar类，再用Calendar的getTime()方法生成对应的Date，最后用SimpleDateFormat输出。

 

1. 获取当期日期、年份、月份

import java.util.Calendar;

public class Main {
  public static void main(String[] args) {
    Calendar now = Calendar.getInstance();
    System.out.println("Current Year is : " + now.get(Calendar.YEAR));
    // month start from 0 to 11
    System.out.println("Current Month is : " + (now.get(Calendar.MONTH) + 1));
    System.out.println("Current Date is : " + now.get(Calendar.DATE));
  }
}

2. 获取前一天、前一个月的日期

Calendar calendar = Calendar.getInstance();//此时打印它获取的是系统当前时间
        calendar.add(Calendar.DATE, -1);    //得到前一天

String  yestedayDate

= new SimpleDateFormat("yyyy-MM-dd").format(cal.getTime());


        calendar.add(Calendar.MONTH, -1);    //得到前一个月
        int year = calendar.get(Calendar.YEAR);


       int month = calendar.get(Calendar.MONTH)+1; //输出前一月的时候要记得加1

3. 字符串转为日期格式

String date = "2010-02-01 23:59:59";

SimpleDateFormat sf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");

try {

Date d = sf.parse(date);

System.out.println(sf.format(d));

} catch (ParseException e) {

e.printStackTrace();

}