Calendar 日历类的基本用法

<p style="margin-top: 0px; margin-bottom: 0px; padding-top: 0px; padding-bottom: 0px; font-family: Arial; font-size: 14px; line-height: 26px; "><a target=_blank href="http://lib.csdn.net/base/17" class="replace_word" title="Java EE知识库" target="_blank" style="color: rgb(223, 52, 52); text-decoration: none; font-weight: bold; ">Java</a> Calendar 类时间操作，这也许是创建日历和管理最简单的一个方案，示范代码很简单。</p><p style="margin-top: 0px; margin-bottom: 0px; padding-top: 0px; padding-bottom: 0px; font-family: Arial; font-size: 14px; line-height: 26px; ">演示了获取时间，日期时间的累加和累减，以及比较。</p><p style="margin-top: 0px; margin-bottom: 0px; padding-top: 0px; padding-bottom: 0px; font-family: Arial; font-size: 14px; line-height: 26px; "></p><p style="margin-top: 0px; margin-bottom: 0px; padding-top: 0px; padding-bottom: 0px; font-family: Arial; font-size: 14px; line-height: 26px; ">注意事项：</p><p style="margin-top: 0px; margin-bottom: 0px; padding-top: 0px; padding-bottom: 0px; font-family: Arial; font-size: 14px; line-height: 26px; ">Calendar 的 month 从 0 开始，也就是全年 12 个月由 0 ~ 11 进行表示。</p><p style="margin-top: 0px; margin-bottom: 0px; padding-top: 0px; padding-bottom: 0px; font-family: Arial; font-size: 14px; line-height: 26px; ">而 Calendar.DAY_OF_WEEK 定义和值如下：</p><p style="margin-top: 0px; margin-bottom: 0px; padding-top: 0px; padding-bottom: 0px; font-family: Arial; font-size: 14px; line-height: 26px; ">Calendar.SUNDAY = 1Calendar.MONDAY = 2Calendar.TUESDAY = 3Calendar.WEDNESDAY = 4Calendar.THURSDAY = 5Calendar.FRIDAY = 6Calendar.SATURDAY = 7</p><p style="margin-top: 0px; margin-bottom: 0px; padding-top: 0px; padding-bottom: 0px; font-family: Arial; font-size: 14px; line-height: 26px; "></p><p style="margin-top: 0px; margin-bottom: 0px; padding-top: 0px; padding-bottom: 0px; font-family: Arial; font-size: 14px; line-height: 26px; ">SimpleDateFormat 的格式定义</p><p style="margin-top: 0px; margin-bottom: 0px; padding-top: 0px; padding-bottom: 0px; font-family: Arial; font-size: 14px; line-height: 26px; "></p><table border="0" cellspacing="3" cellpadding="0" summary="Chart shows pattern letters, date/time component, presentation, and examples." class="          " style="color: rgb(0, 0, 0); font-family: Arial; font-size: 14px; line-height: 26px; text-align: left; "><tbody><tr style="background-color: rgb(204, 204, 255); "><th align="left">Letter</th><th align="left">Date or Time Component</th><th align="left">Presentation</th><th align="left">Examples</th></tr><tr><td><code>G</code></td><td>Era designator</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#text" style="color: rgb(202, 0, 0); text-decoration: none; ">Text</a></td><td><code>AD</code></td></tr><tr style="background-color: rgb(238, 238, 255); "><td><code>y</code></td><td>Year</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#year" style="color: rgb(202, 0, 0); text-decoration: none; ">Year</a></td><td><code>1996</code>; <code>96</code></td></tr><tr><td><code>Y</code></td><td>Week year</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#year" style="color: rgb(202, 0, 0); text-decoration: none; ">Year</a></td><td><code>2009</code>; <code>09</code></td></tr><tr style="background-color: rgb(238, 238, 255); "><td><code>M</code></td><td>Month in year (context sensitive)</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#month" style="color: rgb(202, 0, 0); text-decoration: none; ">Month</a></td><td><code>July</code>; <code>Jul</code>; <code>07</code></td></tr><tr><td><code>L</code></td><td>Month in year (standalone form)</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#month" style="color: rgb(202, 0, 0); text-decoration: none; ">Month</a></td><td><code>July</code>; <code>Jul</code>; <code>07</code></td></tr><tr style="background-color: rgb(238, 238, 255); "><td><code>w</code></td><td>Week in year</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#number" style="color: rgb(202, 0, 0); text-decoration: none; ">Number</a></td><td><code>27</code></td></tr><tr><td><code>W</code></td><td>Week in month</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#number" style="color: rgb(202, 0, 0); text-decoration: none; ">Number</a></td><td><code>2</code></td></tr><tr style="background-color: rgb(238, 238, 255); "><td><code>D</code></td><td>Day in year</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#number" style="color: rgb(202, 0, 0); text-decoration: none; ">Number</a></td><td><code>189</code></td></tr><tr><td><code>d</code></td><td>Day in month</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#number" style="color: rgb(202, 0, 0); text-decoration: none; ">Number</a></td><td><code>10</code></td></tr><tr style="background-color: rgb(238, 238, 255); "><td><code>F</code></td><td>Day of week in month</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#number" style="color: rgb(202, 0, 0); text-decoration: none; ">Number</a></td><td><code>2</code></td></tr><tr><td><code>E</code></td><td>Day name in week</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#text" style="color: rgb(202, 0, 0); text-decoration: none; ">Text</a></td><td><code>Tuesday</code>; <code>Tue</code></td></tr><tr style="background-color: rgb(238, 238, 255); "><td><code>u</code></td><td>Day number of week (1 = Monday, ..., 7 = Sunday)</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#number" style="color: rgb(202, 0, 0); text-decoration: none; ">Number</a></td><td><code>1</code></td></tr><tr><td><code>a</code></td><td>Am/pm marker</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#text" style="color: rgb(202, 0, 0); text-decoration: none; ">Text</a></td><td><code>PM</code></td></tr><tr style="background-color: rgb(238, 238, 255); "><td><code>H</code></td><td>Hour in day (0-23)</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#number" style="color: rgb(202, 0, 0); text-decoration: none; ">Number</a></td><td><code>0</code></td></tr><tr><td><code>k</code></td><td>Hour in day (1-24)</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#number" style="color: rgb(202, 0, 0); text-decoration: none; ">Number</a></td><td><code>24</code></td></tr><tr style="background-color: rgb(238, 238, 255); "><td><code>K</code></td><td>Hour in am/pm (0-11)</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#number" style="color: rgb(202, 0, 0); text-decoration: none; ">Number</a></td><td><code>0</code></td></tr><tr><td><code>h</code></td><td>Hour in am/pm (1-12)</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#number" style="color: rgb(202, 0, 0); text-decoration: none; ">Number</a></td><td><code>12</code></td></tr><tr style="background-color: rgb(238, 238, 255); "><td><code>m</code></td><td>Minute in hour</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#number" style="color: rgb(202, 0, 0); text-decoration: none; ">Number</a></td><td><code>30</code></td></tr><tr><td><code>s</code></td><td>Second in minute</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#number" style="color: rgb(202, 0, 0); text-decoration: none; ">Number</a></td><td><code>55</code></td></tr><tr style="background-color: rgb(238, 238, 255); "><td><code>S</code></td><td>Millisecond</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#number" style="color: rgb(202, 0, 0); text-decoration: none; ">Number</a></td><td><code>978</code></td></tr><tr><td><code>z</code></td><td>Time zone</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#timezone" style="color: rgb(202, 0, 0); text-decoration: none; ">General time zone</a></td><td><code>Pacific Standard Time</code>; <code>PST</code>; <code>GMT-08:00</code></td></tr><tr style="background-color: rgb(238, 238, 255); "><td><code>Z</code></td><td>Time zone</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#rfc822timezone" style="color: rgb(202, 0, 0); text-decoration: none; ">RFC 822 time zone</a></td><td><code>-0800</code></td></tr><tr><td><code>X</code></td><td>Time zone</td><td><a target=_blank target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html?noframes=true#iso8601timezone" style="color: rgb(202, 0, 0); text-decoration: none; ">ISO 8601 time zone</a></td><td><code>-08</code>; <code>-0800</code>; <code>-08:00</code></td></tr></tbody></table><p style="margin-top: 0px; margin-bottom: 0px; padding-top: 0px; padding-bottom: 0px; font-family: Arial; font-size: 14px; line-height: 26px; "></p><p style="margin-top: 0px; margin-bottom: 0px; padding-top: 0px; padding-bottom: 0px; font-family: Arial; font-size: 14px; line-height: 26px; "></p>

package demo;    import java.util.Date;  import java.text.SimpleDateFormat;  import java.text.DateFormat;  import java.text.ParseException;  import java.util.Calendar;    public class Test  {    public Test()    {    }      public static void main(String[] args)    {      // 字符串转换日期格式      // DateFormat fmtDateTime = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");      // 接收传入参数      // String strDate = args[1];      // 得到日期格式对象      // Date date = fmtDateTime.parse(strDate);        // 完整显示今天日期时间      String str = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS")).format(new Date());      System.out.println(str);        // 创建 Calendar 对象      Calendar calendar = Calendar.getInstance();        try      {        // 对 calendar 设置时间的方法        // 设置传入的时间格式        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-M-d H:m:s");        // 指定一个日期        Date date = dateFormat.parse("2013-6-1 13:24:16");        // 对 calendar 设置为 date 所定的日期        calendar.setTime(date);          // 按特定格式显示刚设置的时间        str = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS")).format(calendar.getTime());        System.out.println(str);      }      catch (ParseException e)      {        e.printStackTrace();      }        // 或者另一種設置 calendar 方式      // 分別爲 year, month, date, hourOfDay, minute, second      calendar = Calendar.getInstance();      calendar.set(2013, 1, 2, 17, 35, 44);      str = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS")).format(calendar.getTime());      System.out.println(str);        // Calendar 取得当前时间的方法      // 初始化 (重置) Calendar 对象      calendar = Calendar.getInstance();      // 或者用 Date 来初始化 Calendar 对象      calendar.setTime(new Date());        // setTime 类似上面一行      // Date date = new Date();      // calendar.setTime(date);        str = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS")).format(calendar.getTime());      System.out.println(str);        // 显示年份      int year = calendar.get(Calendar.YEAR);      System.out.println("year is = " + String.valueOf(year));        // 显示月份 (从0开始, 实际显示要加一)      int month = calendar.get(Calendar.MONTH);      System.out.println("nth is = " + (month + 1));        // 本周几      int week = calendar.get(Calendar.DAY_OF_WEEK);      System.out.println("week is = " + week);        // 今年的第 N 天      int DAY_OF_YEAR = calendar.get(Calendar.DAY_OF_YEAR);      System.out.println("DAY_OF_YEAR is = " + DAY_OF_YEAR);        // 本月第 N 天      int DAY_OF_MONTH = calendar.get(Calendar.DAY_OF_MONTH);      System.out.println("DAY_OF_MONTH = " + String.valueOf(DAY_OF_MONTH));        // 3小时以后      calendar.add(Calendar.HOUR_OF_DAY, 3);      int HOUR_OF_DAY = calendar.get(Calendar.HOUR_OF_DAY);      System.out.println("HOUR_OF_DAY + 3 = " + HOUR_OF_DAY);        // 当前分钟数      int MINUTE = calendar.get(Calendar.MINUTE);      System.out.println("MINUTE = " + MINUTE);        // 15 分钟以后      calendar.add(Calendar.MINUTE, 15);      MINUTE = calendar.get(Calendar.MINUTE);      System.out.println("MINUTE + 15 = " + MINUTE);        // 30分钟前      calendar.add(Calendar.MINUTE, -30);      MINUTE = calendar.get(Calendar.MINUTE);      System.out.println("MINUTE - 30 = " + MINUTE);        // 格式化显示      str = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SS")).format(calendar.getTime());      System.out.println(str);        // 重置 Calendar 显示当前时间      calendar.setTime(new Date());      str = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SS")).format(calendar.getTime());      System.out.println(str);        // 创建一个 Calendar 用于比较时间      Calendar calendarNew = Calendar.getInstance();        // 设定为 5 小时以前，后者大，显示 -1      calendarNew.add(Calendar.HOUR, -5);      System.out.println("时间比较：" + calendarNew.compareTo(calendar));        // 设定7小时以后，前者大，显示 1      calendarNew.add(Calendar.HOUR, +7);      System.out.println("时间比较：" + calendarNew.compareTo(calendar));        // 退回 2 小时，时间相同，显示 0      calendarNew.add(Calendar.HOUR, -2);      System.out.println("时间比较：" + calendarNew.compareTo(calendar));    }  }