怎么得到一个时间字符串的月份或者日、小时等？

Question

使用正则表达式取时间可以
([0-9]){2,4}[-|/]([0-9]){1,2}[-|/]]([0-9]){1,2}
匹配到了就取出三个子表达式(括号表示的group)，得到年月日
正则表达式的API你可以使用jdk1.4的，也可以使用apache的

Answer 1

String[] ids = TimeZone.getAvailableIDs(-8 * 60 * 60 * 1000);
 // if no ids were returned, something is wrong. get out.
 if (ids.length == 0)
     System.exit(0);  // begin output
 System.out.println("Current Time"); // create a Pacific Standard Time time zone
 SimpleTimeZone pdt = new SimpleTimeZone(-8 * 60 * 60 * 1000, ids[0]); // set up rules for daylight savings time
 pdt.setStartRule(Calendar.APRIL, 1, Calendar.SUNDAY, 2 * 60 * 60 * 1000);
 pdt.setEndRule(Calendar.OCTOBER, -1, Calendar.SUNDAY, 2 * 60 * 60 * 1000); // create a GregorianCalendar with the Pacific Daylight time zone
 // and the current date and time
 Calendar calendar = new GregorianCalendar(pdt);
 Date trialTime = new Date();
 calendar.setTime(trialTime); // print out a bunch of interesting things
 System.out.println("ERA: "  calendar.get(Calendar.ERA));
 System.out.println("YEAR: "  calendar.get(Calendar.YEAR));
 System.out.println("MONTH: "  calendar.get(Calendar.MONTH));
 System.out.println("WEEK_OF_YEAR: "  calendar.get(Calendar.WEEK_OF_YEAR));
 System.out.println("WEEK_OF_MONTH: "  calendar.get(Calendar.WEEK_OF_MONTH));
 System.out.println("DATE: "  calendar.get(Calendar.DATE));
 System.out.println("DAY_OF_MONTH: "  calendar.get(Calendar.DAY_OF_MONTH));
 System.out.println("DAY_OF_YEAR: "  calendar.get(Calendar.DAY_OF_YEAR));
 System.out.println("DAY_OF_WEEK: "  calendar.get(Calendar.DAY_OF_WEEK));
 System.out.println("DAY_OF_WEEK_IN_MONTH: "
                     calendar.get(Calendar.DAY_OF_WEEK_IN_MONTH));
 System.out.println("AM_PM: "  calendar.get(Calendar.AM_PM));
 System.out.println("HOUR: "  calendar.get(Calendar.HOUR));
 System.out.println("HOUR_OF_DAY: "  calendar.get(Calendar.HOUR_OF_DAY));
 System.out.println("MINUTE: "  calendar.get(Calendar.MINUTE));
 System.out.println("SECOND: "  calendar.get(Calendar.SECOND));
 System.out.println("MILLISECOND: "  calendar.get(Calendar.MILLISECOND));
 System.out.println("ZONE_OFFSET: "
                     (calendar.get(Calendar.ZONE_OFFSET)/(60*60*1000)));
 System.out.println("DST_OFFSET: "
                     (calendar.get(Calendar.DST_OFFSET)/(60*60*1000)));
 
 System.out.println("Current Time, with hour reset to 3");
 calendar.clear(Calendar.HOUR_OF_DAY); // so doesn't override
 calendar.set(Calendar.HOUR, 3);
 System.out.println("ERA: "  calendar.get(Calendar.ERA));
 System.out.println("YEAR: "  calendar.get(Calendar.YEAR));
 System.out.println("MONTH: "  calendar.get(Calendar.MONTH));
 System.out.println("WEEK_OF_YEAR: "  calendar.get(Calendar.WEEK_OF_YEAR));
 System.out.println("WEEK_OF_MONTH: "  calendar.get(Calendar.WEEK_OF_MONTH));
 System.out.println("DATE: "  calendar.get(Calendar.DATE));
 System.out.println("DAY_OF_MONTH: "  calendar.get(Calendar.DAY_OF_MONTH));
 System.out.println("DAY_OF_YEAR: "  calendar.get(Calendar.DAY_OF_YEAR));
 System.out.println("DAY_OF_WEEK: "  calendar.get(Calendar.DAY_OF_WEEK));
 System.out.println("DAY_OF_WEEK_IN_MONTH: "
                     calendar.get(Calendar.DAY_OF_WEEK_IN_MONTH));
 System.out.println("AM_PM: "  calendar.get(Calendar.AM_PM));
 System.out.println("HOUR: "  calendar.get(Calendar.HOUR));
 System.out.println("HOUR_OF_DAY: "  calendar.get(Calendar.HOUR_OF_DAY));
 System.out.println("MINUTE: "  calendar.get(Calendar.MINUTE));
 System.out.println("SECOND: "  calendar.get(Calendar.SECOND));
 System.out.println("MILLISECOND: "  calendar.get(Calendar.MILLISECOND));
 System.out.println("ZONE_OFFSET: "
         (calendar.get(Calendar.ZONE_OFFSET)/(60*60*1000))); // in hours
 System.out.println("DST_OFFSET: "
         (calendar.get(Calendar.DST_OFFSET)/(60*60*1000))); // in hours

Answer 2

import java.awt.Graphics;
import java.applet.Applet;
import java.util.Calendar;
class Time{
    t=Calendar.getInstence();
y=t.get(t.YEAR);
m=t.get(t.MONTH)+1;
d=t.get(t.DATE);
hh=t.get(t.HOUR_OF_DAY);
mm=t.get(t.MINUTER);
ss=t.get(t.SECOND);
} public String getDate(){
return y+"年"+m+"月"+d+"日";
 }
 public String getTime(){
String s=hh+"时"+mm+"分"+ss+"秒";
return s;
 }
}  public class ShowTime extends Applet{
Time t=new Time();
  public void paint(Graphics g){
   g.drawString("当前日期:"+t.getDate(),50,40);
   g.drawString("当前时间:"+t.getTime(),50,80);
   }
 }

Answer 3

给你一段经典代码：
String s1="2000/02/05-09-08";
SimpleDateFormat simpledateformat = new SimpleDateFormat("yyyy/MM/dd-HH-mm");
Date date = simpledateformat.parse(s1);
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
System.out.println("month is: "+calendar.get(Calendar.MONTH)+1);
System.out.println("date is: "+calendar.get(Calendar.HOUR_OF_DAY));
try一try？
why not？

Answer 4

SimpleDateFormat 找不到，我的字符串是从sql数据库里取出来的，怎么转换呢？我正在一一的试，大家不要着急，分会给的，我再加20分，麻烦各位给我说清楚点好吗，谢谢！

Answer 5

select to_char(sysdate,'yyyy-MM-dd hh24:ss') from dual
然后再处理.SQL语句更好做啊!

Answer 6

java.text 
Class SimpleDateFormat
java.lang.Object
  |
  +-java.text.Format
        |
        +-java.text.DateFormat
              |
              +-java.text.SimpleDateFormat我用的jdk1.3有这个类。
具体的看文档，讲的很清楚。我基本上也是看文档学的还有哇，如果一个类找不到，可以试着用JWhichimport java.io.PrintStream;
import java.net.URL;public class JWhich
{
    public static void which(String s)
    {
        if(!s.startsWith("/"))
            s = "/" + s;
        s = s.replace('.', '/');
        s = s + ".class";
        URL url = (new JWhich()).getClass().getResource(s);
        if(url != null)
            System.out.println("\nClass '" + s + "' found in \n'" + url.getFile() + "'");
        else
            System.out.println("\nClass '" + s + "' not found in \n'" + System.getProperty("java.class.path") + "'");
    }    public static void which(String s, String s1)
    {
        System.setProperty("java.class.path", s1);
        which(s);
    }    public static void main(String args[])
    {
        if(args.length == 1)
            which(args[0]);
        else
        if(args.length == 2)
            which(args[0], args[1]);
        else
            System.err.println("Usage: java JWhich <classname> [classpath]");
    }
}

Answer 7

用java.text.SimpleDateFormat是标准的方法，不过你要把你的字符串格式规定好，特别是小时的格式，是0到23还是1到24，有没有AM/PM等。

Answer 8

再请教一下fightboy，我给你加分，但是出现 "贴子回复次数大于跟给分次数 "，什么意思，还有我想多给点分，但是他说给的分数大于40什么的，告诉我怎么给你分