org.apache.commons.lang.time用法实例

<table style="color:rgb(68, 68, 68);"><tbody><tr><td><div><div><p>org.apache.commons.lang.time。这个包里面包含了如下5个类：</p><p> </p><p><span style="color:navy;">DateFormatUtils – </span><span style="color:navy;">提供格式化日期和时间的功能及相关常量；</span></p><p><span style="color:navy;">DateUtils – </span><span style="color:navy;">在</span><span style="color:navy;">Calendar</span><span style="color:navy;">和</span><span style="color:navy;">Date</span><span style="color:navy;">的基础上提供更方便的访问；</span></p><p><span style="color:navy;">DurationFormatUtils – </span><span style="color:navy;">提供格式化时间跨度的功能及相关常量；</span></p><p><span style="color:navy;">FastDateFormat – </span><span style="color:navy;">为</span><span style="color:navy;">java.text.SimpleDateFormat</span><span style="color:navy;">提供一个的线程安全的替代类；</span></p><p><span style="color:navy;">StopWatch – </span><span style="color:navy;">是一个方便的计时器。</span></p><p> </p><p>我们还是在一个例子中来看上述各个类的用法吧：</p><p> </p><p><strong><span style="color:navy;">package</span></strong> sean.study.jakarta.commons.lang;</p><p> </p><p><strong><span style="color:navy;">import</span></strong> java.util.Calendar;</p><p><strong><span style="color:navy;">import</span></strong> java.util.Date;</p><p> </p><p><strong><span style="color:navy;">import</span></strong> org.apache.commons.lang.StringUtils;</p><p><strong><span style="color:navy;">import</span></strong> org.apache.commons.lang.time.DateFormatUtils;</p><p><strong><span style="color:navy;">import</span></strong> org.apache.commons.lang.time.DateUtils;</p><p><strong><span style="color:navy;">import</span></strong> org.apache.commons.lang.time.FastDateFormat;</p><p><strong><span style="color:navy;">import</span></strong> org.apache.commons.lang.time.StopWatch;</p><p> </p><p><strong><span style="color:navy;">public</span> <span style="color:navy;">class</span></strong> DateTimeUsage {</p><p> </p><p>    <strong><span style="color:navy;">public</span> <span style="color:navy;">static</span> <span style="color:navy;">void</span></strong> main(String[] args) {</p><p>        demoDateUtils();</p><p>        demoStopWatch();</p><p>    }</p><p>   </p><p>    <strong><span style="color:navy;">public</span> <span style="color:navy;">static</span> <span style="color:navy;">void</span></strong> demoDateUtils() {</p><p>        System.out.println(StringUtils.center(<span style="color:blue;">" demoDateUtils "</span>, 30, <span style="color:blue;">"="</span>));</p><p>        Date date = <strong><span style="color:navy;">new</span></strong> Date();</p><p>        String isoDateTime = DateFormatUtils.ISO_DATETIME_FORMAT.format(date);</p><p>        String isoTime = DateFormatUtils.ISO_TIME_NO_T_FORMAT.format(date);</p><p>        FastDateFormat fdf = FastDateFormat.getInstance(<span style="color:blue;">"yyyy-MM"</span>);</p><p>        String customDateTime = fdf.format(date);</p><p>        System.out.println(<span style="color:blue;">"ISO_DATETIME_FORMAT: "</span> + isoDateTime);</p><p>        System.out.println(<span style="color:blue;">"ISO_TIME_NO_T_FORMAT: "</span> + isoTime);</p><p>        System.out.println(<span style="color:blue;">"Custom FastDateFormat: "</span> + customDateTime);</p><p>        System.out.println(<span style="color:blue;">"Default format: "</span> + date);</p><p>        System.out.println(<span style="color:blue;">"Round HOUR: "</span> + DateUtils.round(date, Calendar.HOUR));</p><p>        System.out.println(<span style="color:blue;">"Truncate HOUR: "</span> + DateUtils.truncate(date, Calendar.HOUR));</p><p>        System.out.println();</p><p>    }</p><p>   </p><p>    <strong><span style="color:navy;">public</span> <span style="color:navy;">static</span> <span style="color:navy;">void</span></strong> demoStopWatch() {</p><p>        System.out.println(StringUtils.center(<span style="color:blue;">" demoStopWatch "</span>, 30, <span style="color:blue;">"="</span>));</p><p>        StopWatch sw = new StopWatch();</p><p>        sw.start();</p><p>        operationA();</p><p>        sw.stop();</p><p>        System.out.println(<span style="color:blue;">"operationA used "</span> + sw.getTime() + <span style="color:blue;">" milliseconds."</span>);</p><p>        System.out.println();</p><p>    }</p><p>   </p><p>    <strong><span style="color:navy;">public</span> <span style="color:navy;">static</span> <span style="color:navy;">void</span></strong> operationA() {</p><p>        <strong><span style="color:navy;">try</span></strong> {</p><p>            Thread.sleep(999);</p><p>        }</p><p>        <strong><span style="color:navy;">catch</span></strong> (InterruptedException e) {</p><p><span style="color:green;">            // do nothing</span></p><p>        }</p><p>    }</p><p> </p><p>}</p><p> </p><p>以下是运行结果：</p><p> </p><p align="left"><span style="color:navy;">======= demoDateUtils ========</span></p><p align="left"><span style="color:navy;">ISO_DATETIME_FORMAT: 2005-08-01T12:41:51</span></p><p align="left"><span style="color:navy;">ISO_TIME_NO_T_FORMAT: 12:41:51</span></p><p align="left"><span style="color:navy;">Custom FastDateFormat: 2005-08</span></p><p align="left"><span style="color:navy;">Default format: Mon Aug 01 12:41:51 CST 2005</span></p><p align="left"><span style="color:navy;">Round HOUR: Mon Aug 01 13:00:00 CST 2005</span></p><p align="left"><span style="color:navy;">Truncate HOUR: Mon Aug 01 12:00:00 CST 2005</span></p><p align="left"><span style="color:navy;"> </span></p><p align="left"><span style="color:navy;">======= demoStopWatch ========</span></p><p align="left"><span style="color:navy;">operationA used 1000 milliseconds.</span></p></div></div></td></tr></tbody></table>

org.apache.commons.lang.time.DateUtils(常用的一些函数）
static java.util.Date addDays(java.util.Date date,int amount)
 //Adds a number of days to a date returning a new object.
//一个日期对象＋n天
static java.util.Date addHours(java.util.Date date,int amount)
　　 //Adds a number of hours to a date returning a new object.
//一个日期对象＋n小时
static java.util.Date addMilliseconds(java.util.Date date,int amount)
 //Adds a number of milliseconds to a date returning a new object.
//一个日期对象+n毫秒
static java.util.Date addMinutes(java.util.Date date,int amount)
 //Adds a number of minutes to a date returning a new object.
//一个日期对象+n分
static java.util.Date addMonths(java.util.Date date,int amount)
 //Adds a number of months to a date returning a new object.
//一个日期对象＋n月
static java.util.Date addSeconds(java.util.Date date,int amount)
　　 //Adds a number of seconds to a date returning a new object.
　　 //一个日期对象＋n秒
static java.util.Date addWeeks(java.util.Date date,int amount)
 //Adds a number of weeks to a date returning a new object.
//一个日期对象＋N个星期
static java.util.Date addYears(java.util.Date date,int amount)
 //Adds a number of years to a date returning a new object.
//一个日期对象＋N年
static boolean isSameDay(java.util.Date date1,java.util.Date date2)
 //Checks if two date objects are on the same day ignoring time.
//两个日期对象是否相等（只比较年－月－日）
static boolean isSameInstant(java.util.Date date1,java.util.Date date2)
 //Checks if two date objects represent the same instant in time.
//比较两个日期是否完全相等（精确到毫秒）
static java.util.Date parseDate(java.lang.String str,java.lang.String[] parsePatterns)
 //Parses a string representing a date by trying a variety of different parsers.
 //例 1：
 String[] format={"yyyy-MM-dd"};
System.out.println(DateUtils.parseDate("2009-10-20",format));
2：
new SimpleDateFormat("yyyy-MM-dd").format(DateUtils.addMilliseconds(new Date(), 7000))