Java Date 跟 Calendar 实例

Java 之 Date 和 Calendar 实例
[java] view plaincopyprint?
package com.homer.learn;  
  
import java.text.DateFormat;  
import java.text.ParsePosition;  
import java.text.SimpleDateFormat;  
import java.util.Calendar;  
import java.util.Date;  
import java.util.GregorianCalendar;  
  
  
public class TimeTest {  
    public static void main(String[] args) {  
        TimeTest tt = new TimeTest();  
  
        System.out.println("\n当前日期： ");  
        System.out.println(tt.getNowTime());                    // 获取当前时间  
        System.out.println(tt.getNowTime2());                   // 获取当前时间  
        System.out.println(tt.getNowTime3());                   // 获取当前时间  
          
        System.out.println("\n计算周： ");  
        System.out.println(tt.getDaysOfNow2SundayInWeek());     // 获取当前日期与本周日的相差天数  
        System.out.println(tt.getDateOfMondayInWeek());         // 获取本周一的日期  
        System.out.println(tt.getDateOfSaturdayInWeek());       // 获取本周六的日期  
        System.out.println(tt.getDateOfSaturdayInNextWeek());   // 获取下周一的日期  
        System.out.println(tt.getDateOfSaturdayInLastWeek());   // 获取上周一的日期  
  
  
        System.out.println("\n计算月： ");  
        System.out.println(tt.getFirstDayOfMonth());            // 获取当月的第一天  
        System.out.println(tt.getLastDayOfMonth());             // 获取当月最后一天  
        System.out.println(tt.getFirstDayOfPreviousMonth());    // 获取上月第一天        
        System.out.println(tt.getLastDayOfPreviousMonth());     // 获取上月最后一天           
        System.out.println(tt.getFirstDayOfNextMonth());        // 获取下月第一天    
        System.out.println(tt.getLastDayOfNextMonth());         // 获取下月最后一天  
          
  
        System.out.println("\n计算年： ");  
        System.out.println(tt.getFirstDayOfYear());             // 获取本年的第一天  
        System.out.println(tt.getLastDayOfYear());              // 获取本年最后一天  
        System.out.println(tt.getFirstDayOfPreviousYear());     // 获取上年的第一天  
        System.out.println(tt.getLastDayOfPreviousYear());      // 获取上年最后一天  
        System.out.println(tt.getFirstDayOfNextYear());         // 获取下年的第一天  
        System.out.println(tt.getLastDayOfNextYear());          // 获取下年最后一天  
        System.out.println(tt.getDaysOfYear());                 // 获取本年的天数  
          
  
        System.out.println("\n计算季度： ");  
        System.out.println(tt.getSeasonOfMonth());              // 获取当前月的季度  
        System.out.println(tt.getLastDayOfNow());               // 获取当前天所在月份的天数  
        System.out.println(tt.isLeapYear(2012));                // 判断是否是润年  
          
  
        System.out.println("\n日期格式转换与计算： ");  
        System.out.println(tt.getDateFromStr("2012-06-20"));    // 将字符串时间格式 yyyy-MM-dd，转换成Date类型  
        System.out.println(tt.getWeek("2012-06-20"));           // 根据一个日期，返回是星期几的字符串  
        System.out.print("2012-06-02 -> 2012-06-12间隔天数:");   // 计算两个日期间的间隔天数  
        System.out.println(tt.getDaysFromTwoDate("2012-06-02", "2012-06-12"));            
    }  
  
      
      
    // 获取当前时间  
    public String getNowTime() {  
        SimpleDateFormat sDateFormat = new SimpleDateFormat("yyyy-MM-dd");  
          
        Date now = new Date();  
        return sDateFormat.format(now);  
    }  
  
    public String getNowTime2() {  
        SimpleDateFormat sDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");  
          
        Date now = new Date(System.currentTimeMillis());  
        return sDateFormat.format(now);  
    }  
  
    public String getNowTime3() {  
        StringBuilder strBuildNow = new StringBuilder();  
          
        Calendar calendar = Calendar.getInstance();  
        int year = calendar.get(Calendar.YEAR);  
        int month = calendar.get(Calendar.MONTH) + 1;  
        int day = calendar.get(Calendar.DAY_OF_MONTH);  
        int hour = calendar.get(Calendar.HOUR_OF_DAY);  
        int minute = calendar.get(Calendar.MINUTE);  
        int second = calendar.get(Calendar.SECOND);  
        int millissecond = calendar.get(Calendar.MILLISECOND);  
          
        strBuildNow.append(year + "-");  
        strBuildNow.append(month + "-");  
        strBuildNow.append(day + " ");  
        strBuildNow.append(hour + ":");  
        strBuildNow.append(minute + ":");  
        strBuildNow.append(second + ".");  
        strBuildNow.append(millissecond);  
          
        return strBuildNow.toString();  
    }  
      
      
      
      
    // 获取当前日期与本周日的相差天数  
    public int getDaysOfNow2SundayInWeek() {  
        Calendar calendar = Calendar.getInstance();  
          
        int dayOfWeek = calendar.get(Calendar.DAY_OF_WEEK) - 1;     // 减一天，周一为1，符合中国人习惯。Sunday - 1; Monday - 2; Saturday - 7  
        if(dayOfWeek == 0) {        // 周日  
            return 0;  
        } else {  
            return 0 - dayOfWeek;  
        }  
    }  
      
    // 获取本周一的日期  
    public String getDateOfMondayInWeek(){  
        int day = this.getDaysOfNow2SundayInWeek() + 1; // 加1，即周一离本周日的间隔天数  
        GregorianCalendar gCalendar = new GregorianCalendar();  
          
        gCalendar.add(GregorianCalendar.DATE, day);     // 计算与本周一相差的时间间隔  
        Date curDay = gCalendar.getTime();  
          
        DateFormat dateFormat = DateFormat.getInstance();  
        String dateOfMonday = dateFormat.format(curDay);  
          
        return dateOfMonday;  
    }  
  
    // 获取本周六的日期  
    public String getDateOfSaturdayInWeek(){  
        int day = this.getDaysOfNow2SundayInWeek() + 6; // 加6，即周六离本周日的间隔天数  
        GregorianCalendar gCalendar = new GregorianCalendar();  
          
        gCalendar.add(GregorianCalendar.DATE, day);     // 计算与本周六相差的时间间隔  
        Date curDay = gCalendar.getTime();  
          
        DateFormat dateFormat = DateFormat.getInstance();  
        String dateOfMonday = dateFormat.format(curDay);  
          
        return dateOfMonday;  
    }  
  
    // 获取上周一的日期  
    public String getDateOfSaturdayInLastWeek(){  
        int day = this.getDaysOfNow2SundayInWeek() - 1; // 减1，即上周一离本周日的间隔天数  
        GregorianCalendar gCalendar = new GregorianCalendar();  
          
        gCalendar.add(GregorianCalendar.DATE, day);     // 计算与上周一相差的时间间隔  
        Date curDay = gCalendar.getTime();  
          
        DateFormat dateFormat = DateFormat.getInstance();  
        String dateOfMonday = dateFormat.format(curDay);  
          
        return dateOfMonday;  
    }  
      
    // 获取下周一的日期  
    public String getDateOfSaturdayInNextWeek(){  
        int day = this.getDaysOfNow2SundayInWeek() + 8; // 加8，即下周一离本周日的间隔天数  
        GregorianCalendar gCalendar = new GregorianCalendar();  
          
        gCalendar.add(GregorianCalendar.DATE, day);     // 计算与下周一相差的时间间隔  
        Date curDay = gCalendar.getTime();  
          
        DateFormat dateFormat = DateFormat.getInstance();  
        String dateOfMonday = dateFormat.format(curDay);  
          
        return dateOfMonday;  
    }  
      
      
      
  
    // 获取当月第一天  
    public String getFirstDayOfMonth() {  
        String strFirstDay = "";  
        SimpleDateFormat sDateFormat = new SimpleDateFormat("yyyy-MM-dd");  
          
        Calendar calendar = Calendar.getInstance();  
        calendar.set(Calendar.DATE, 1);     // 设置当前月的1号  
          
        strFirstDay = sDateFormat.format(calendar.getTime());  
        return strFirstDay;  
    }  
  
    // 获取当月最后一天  
    public String getLastDayOfMonth() {  
        String strLastDay = "";  
        SimpleDateFormat sDateFormat = new SimpleDateFormat("yyyy-MM-dd");  
          
        Calendar calendar = Calendar.getInstance();  
        calendar.set(Calendar.DATE, 1);     // 设置当前月的1号  
        calendar.add(Calendar.MONDAY, 1);   // 加一个月，变为下月的1号  
        calendar.add(Calendar.DATE, -1);    // 减去一天，变为当前月的最后一天  
          
        strLastDay = sDateFormat.format(calendar.getTime());  
        return strLastDay;  
    }  
  
    // 获取上月第一天  
    public String getFirstDayOfPreviousMonth() {  
        String strFirstDay = "";  
        SimpleDateFormat sDateFormat = new SimpleDateFormat("yyyy-MM-dd");  
          
        Calendar calendar = Calendar.getInstance();  
        calendar.set(Calendar.DATE, 1);     // 设置当前月的1号  
        calendar.add(Calendar.MONDAY, -1);  // 减一个月，变为上月的1号  
          
        strFirstDay = sDateFormat.format(calendar.getTime());  
        return strFirstDay;  
    }  
  
    // 获取上月最后一天  
    public String getLastDayOfPreviousMonth() {  
        String strLastDay = "";  
        SimpleDateFormat sDateFormat = new SimpleDateFormat("yyyy-MM-dd");  
          
        Calendar calendar = Calendar.getInstance();  
        calendar.set(Calendar.DATE, 1);     // 设置当前月的1号  
        calendar.add(Calendar.DATE, -1);    // 减一天，变为上月的1号  
          
        strLastDay = sDateFormat.format(calendar.getTime());  
        return strLastDay;  
    }  
  
    public String getLastDayOfPreviousMonth2() {  
        String strLastDay = "";  
        SimpleDateFormat sDateFormat = new SimpleDateFormat("yyyy-MM-dd");  
          
        Calendar calendar = Calendar.getInstance();  
        calendar.add(Calendar.MONDAY, -1);  // 减一个月  
        calendar.set(Calendar.DATE, 1);     // 设置当前月的1号  
        calendar.roll(Calendar.DATE, -1);   // 把日期回滚一天，也就是本月最后一天  
          
        strLastDay = sDateFormat.format(calendar.getTime());  
        return strLastDay;  
    }  
      
    // 获取下月第一天  
    public String getFirstDayOfNextMonth() {  
        String strFirstDay = "";  
        SimpleDateFormat sDateFormat = new SimpleDateFormat("yyyy-MM-dd");  
          
        Calendar calendar = Calendar.getInstance();  
        calendar.add(Calendar.MONTH, 1);    // 加一个月  
        calendar.set(Calendar.DATE, 1);     // 设置当前月第一天  
          
        strFirstDay = sDateFormat.format(calendar.getTime());  
        return strFirstDay;  
    }  
  
    // 获取下月最后一天  
    public String getLastDayOfNextMonth() {  
        String strLastDay = "";  
        SimpleDateFormat sDateFormat = new SimpleDateFormat("yyyy-MM-dd");  
          
        Calendar calendar = Calendar.getInstance();  
        calendar.set(Calendar.DATE, 1);     // 设置当前月的1号  
        calendar.add(Calendar.MONDAY, 2);   // 加两个月，变为下下月的1号  
        calendar.add(Calendar.DATE, -1);    // 减一天，变为下月的最后一天  
          
        strLastDay = sDateFormat.format(calendar.getTime());  
        return strLastDay;  
    }  
  
    public String getLastDayOfNextMonth2(){  
        String strLastDay = "";  
        SimpleDateFormat sDateFormat = new SimpleDateFormat("yyyy-MM-dd");  
          
        Calendar calendar = Calendar.getInstance();  
        calendar.add(Calendar.MONTH, 1);    // 加1个月  
        calendar.set(Calendar.DATE, 1);     // 把日期设置为当月第1天  
        calendar.roll(Calendar.DATE, -1);   // 日期回滚1天，也就是本月最后1天  
          
        strLastDay = sDateFormat.format(calendar.getTime());  
        return strLastDay;  
    }  
      
      
      
      
    // 获取本年的第一天  
    public String getFirstDayOfYear(){  
        String strFirstDay = "";  
        SimpleDateFormat sDateFormat = new SimpleDateFormat("yyyy-MM-dd");  
          
        Calendar calendar = Calendar.getInstance();  
        calendar.set(Calendar.DAY_OF_YEAR, 1);      // 设置当年第一天  
          
        strFirstDay = sDateFormat.format(calendar.getTime());  
        return strFirstDay;  
    }  
  
    // 获取本年的最后一天  
    public String getLastDayOfYear(){  
        String strLastDay = "";  
          
        Calendar calendar = Calendar.getInstance();  
        strLastDay = calendar.get(Calendar.YEAR) + "-12-31";  
          
        return strLastDay;  
    }  
      
    // 获取上年的第一天  
    public String getFirstDayOfPreviousYear(){  
        String strFirstDay = "";  
          
        Calendar calendar = Calendar.getInstance();  
        strFirstDay = (calendar.get(Calendar.YEAR) - 1) + "-01-01";  
          
        return strFirstDay;  
    }  
  
    // 获取上年的最后一天  
    public String getLastDayOfPreviousYear(){  
        String strLastDay = "";  
          
        Calendar calendar = Calendar.getInstance();  
        strLastDay = (calendar.get(Calendar.YEAR) - 1) + "-12-31";  
          
        return strLastDay;  
    }  
      
    // 获取下年的第一天  
    public String getFirstDayOfNextYear(){  
        String strFirstDay = "";  
        SimpleDateFormat sDateFormat = new SimpleDateFormat("yyyy-MM-dd");  
          
        Calendar calendar = Calendar.getInstance();  
        calendar.add(Calendar.YEAR, 1);             // 加一年  
        calendar.set(Calendar.DAY_OF_YEAR, 1);      // 设置当年第一天  
          
        strFirstDay = sDateFormat.format(calendar.getTime());  
        return strFirstDay;  
    }  
  
    // 获取下年的最后一天  
    public String getLastDayOfNextYear(){  
        String strLastDay = "";  
        SimpleDateFormat sDateFormat = new SimpleDateFormat("yyyy-MM-dd");  
          
        Calendar calendar = Calendar.getInstance();  
        calendar.add(Calendar.YEAR, 1);             // 加一年  
        calendar.set(Calendar.DAY_OF_YEAR, 1);      // 设置当年第一天  
        calendar.roll(Calendar.DAY_OF_YEAR, -1);    // 回滚到当年最后一天  
          
        strLastDay = sDateFormat.format(calendar.getTime());  
        return strLastDay;  
    }  
      
    // 获取本年的天数  
    public String getDaysOfYear(){  
        int year = 0;  
        int days = 0;  
          
        Calendar calendar = Calendar.getInstance();  
        calendar.set(Calendar.DAY_OF_YEAR, 1);      // 设置日期为当年第一天  
        calendar.roll(Calendar.DAY_OF_YEAR, -1);    // 把日期回滚一天  
          
        year = calendar.get(Calendar.YEAR);  
        days = calendar.get(Calendar.DAY_OF_YEAR);  
          
        return (days + " in " + year);  
    }  
      
      
      
      
    // 获取当前月的季度  
    public String getSeasonOfMonth(){  
        String strSeason = "";  
        int year, month, day;  
        int season = 1;  
        int array[][] = new int[][]{ {1,2,3}, {4,5,6}, {7,8,9}, {10,11,12} };  
          
        Calendar calendar = Calendar.getInstance();  
        year = calendar.get(Calendar.YEAR);  
        month = calendar.get(Calendar.MONDAY) + 1;  
        day = calendar.get(Calendar.DAY_OF_MONTH);  
        switch (month) {  
        case 1:  
        case 2:  
        case 3:  
            season = 1;  
            break;  
        case 4:  
        case 5:  
        case 6:  
            season = 2;  
            break;  
        case 7:  
        case 8:  
        case 9:  
            season = 3;  
            break;  
        case 10:  
        case 11:  
        case 12:  
            season = 4;  
            break;  
        default:  
            season = 1;  
            break;  
        }  
          
          
        int start_month = array[season-1][0];  
        int end_month = array[season-1][2];  
        strSeason = year + "-" + month + "-" +day;  
        strSeason += " in [ " + year + "-" + start_month + " : " + year + "-" + end_month + " ]";  
          
        return strSeason;  
    }  
      
      
    // 获取当前天所在月份的天数  
    public String getLastDayOfNow(){  
        String strLastDay = "";  
        int year, month, day;  
        int days = 0;  
          
        Calendar calendar = Calendar.getInstance();  
        year = calendar.get(Calendar.YEAR);  
        month = calendar.get(Calendar.MONTH) + 1;  
        day = calendar.get(Calendar.DAY_OF_MONTH);  
          
        switch (month) {  
        case 1:  
        case 3:  
        case 5:  
        case 7:  
        case 8:  
        case 10:  
        case 12:  
            days = 31;  
            break;  
        case 4:  
        case 6:  
        case 9:  
        case 11:  
            days = 30;  
            break;  
        case 2:  
            if (isLeapYear(year)) {  
                days = 29;  
            } else {  
                days = 28;  
            }  
            break;  
        default:  
            days = 0;  
            break;  
        }  
          
        strLastDay = days + " in [ " + year + "-" + month + "-" + day + " ]";  
        return strLastDay;  
    }  
      
    // 判断是否是润年  
    public boolean isLeapYear(int year){  
        return (year%4 == 0 && year%100 != 0) || (year%400 == 0);  
    }  
      
      
      
      
  
    // 将字符串时间格式 yyyy-MM-dd，转换成Date类型  
    public Date getDateFromStr(String txtDate) {  
        SimpleDateFormat sDateFormat = new SimpleDateFormat("yyyy-MM-dd");  
        ParsePosition pos = new ParsePosition(0);  
        Date date = sDateFormat.parse(txtDate, pos);  
          
        return date;  
    }  
  
    // 根据一个日期，返回是星期几的字符串  
    public String getWeek(String txtDate) {  
        Date date = getDateFromStr(txtDate);  
        Calendar calendar = Calendar.getInstance();  
          
        calendar.setTime(date);  
        String week = new SimpleDateFormat("EEEE").format(date);  
          
        return week;  
    }  
  
    // 计算两个日期间的间隔天数  
    public long getDaysFromTwoDate(String txtDate1, String txtDate2) {  
        if(txtDate1 == null || txtDate1.equals("")) {  
            return 0;  
        }  
        if(txtDate2 == null || txtDate2.equals("")) {  
            return 0;  
        }  
          
        SimpleDateFormat sDateFormat = new SimpleDateFormat("yyyy-MM-dd");  
        long days = 0;  
        try {  
            Date date1 = sDateFormat.parse(txtDate1);  
            Date date2 = sDateFormat.parse(txtDate2);  
            days = (date2.getTime() - date1.getTime())/(24*60*60*1000);     // 通过getTime()方法，把时间Date转换成毫秒格式Long类型，进行计算  
        } catch (Exception e) {  
            System.out.println(e.getMessage());  
        }  
          
        return days;  
    }  
      
}  
运行结果：
当前日期： 
2012-03-07
2012-03-07 12:30:11
2012-3-7 12:30:11.101

计算周： 
-3
3/5/12 12:30 PM
3/10/12 12:30 PM
3/12/12 12:30 PM
3/3/12 12:30 PM

计算月： 
2012-03-01
2012-03-31
2012-02-01
2012-02-29
2012-04-01
2012-04-30

计算年： 
2012-01-01
2012-12-31
2011-01-01
2011-12-31
2013-01-01
2013-12-31
366 in 2012

计算季度： 
2012-3-7 in [ 2012-1 : 2012-3 ]
31 in [ 2012-3-7 ]
true

日期格式转换与计算： 
Wed Jun 20 00:00:00 CST 2012
Wednesday
2012-06-02 -> 2012-06-12间隔天数:10