一个日期转换的问题

greenflute · 发表于 2008-1-3 23:08

原帖由 iooyoo 于 2008-1-3 19:59 发表
jdk_1.5.0_12

public class TestMain {
static void test1() {
      SimpleDateFormat vsdf = null;
      Date vdate = null;
      vsdf = new SimpleDateFormat("yyyyMMddhhmmss";
      vsdf.setLenient(false);
      try {
         vdate = vsdf.parse("19910414000000";
      }
      catch (Exception e) {
         e.printStackTrace();
      }
      System.out.println(vdate);
}

static void test2() {
      SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmss";
      try {
         Date date = sdf.parse("19910414000000";
         System.out.println(date);
      }
      catch (ParseException e) {
         e.printStackTrace();
      }
}

static void test3() {
      SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddhhmmss";
      try {
         Date date = sdf.parse("19910414000000";
         System.out.println(date);
      }
      catch (ParseException e) {
         e.printStackTrace();
      }
}

public static void main(String[] args) {
      test1();
      try {
         Thread.sleep(2000);
      }
      catch (InterruptedException e) {
      }
      test2();
      try {
         Thread.sleep(2000);
      }
      catch (InterruptedException e) {
      }
      test3();
}
}

null
java.text.ParseException: Unparseable date: "19910414000000"
at java.text.DateFormat.parse(Unknown Source)
at com.iooyoo.comics.TestMain.test1(TestMain.java:14)
at com.iooyoo.comics.TestMain.main(TestMain.java:45)
Sun Apr 14 01:00:00 CST 1991
Sun Apr 14 01:00:00 CST 1991

一个是jdk1.5.0_13，一个是jdk1.5.0_12，真的怀疑是这几个版本的bug了

iooyoo · 发表于 2008-1-4 09:20

回去试了一下，好像不是，这个时间点有点问题，不知道楼主怎么试出来这个的

iooyoo · 发表于 2008-1-4 09:29

似乎 1991-4-14 00:00:00 和 1991-4-14 01:00:00没有区别

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
public class TestMain {
private static SimpleDateFormat format = new SimpleDateFormat(
"yyyy-MM-dd HH:mm:ss");
public static void main(String[] args) {
test4(1991, 3, 14, 2, 0, 0, -1);
test4(1991, 3, 14, 2, 0, 0, -2);
test4(1991, 3, 14, 2, 0, 0, -3);
test4(1991, 3, 14, 0, 0, 0, -1);
System.out.println();
test4(1992, 3, 15, 2, 0, 0, -1);
test4(1992, 3, 15, 2, 0, 0, -2);
test4(1992, 3, 15, 2, 0, 0, -3);
test4(1992, 3, 15, 0, 0, 0, -1);
System.out.println();
test4(1991, 4, 14, 2, 0, 0, -1);
test4(1991, 4, 14, 2, 0, 0, -2);
test4(1991, 4, 14, 2, 0, 0, -3);
test4(1991, 4, 14, 0, 0, 0, -1);
System.out.println();
test4(1992, 3, 15, 2, 0, 0, -1);
test4(1992, 3, 15, 2, 0, 0, -2);
test4(1992, 3, 15, 2, 0, 0, -3);
test4(1992, 3, 15, 0, 0, 0, -1);
}
static void test4(int year, int month, int day, int hour, int minute,
int second, int hourAmount) {
GregorianCalendar gc = new GregorianCalendar();
gc.set(year, month, day, hour, minute, second);
GregorianCalendar gc1 = new GregorianCalendar();
gc1.setTimeInMillis(gc.getTimeInMillis());
gc1.add(Calendar.HOUR, hourAmount);
long t1 = gc.getTimeInMillis() - gc1.getTimeInMillis();
System.out.println(format.format(gc.getTime()) + " to "
+ format.format(gc1.getTime()) + " is " + t1 / 1000L / 60
+ " minutes.");
}
}
--------------------------
1991-04-14 02:00:00 to 1991-04-14 01:00:00 is 60 minutes.
1991-04-14 02:00:00 to 1991-04-13 23:00:00 is 120 minutes.
1991-04-14 02:00:00 to 1991-04-13 22:00:00 is 180 minutes.
1991-04-14 01:00:00 to 1991-04-13 23:00:00 is 60 minutes.
1992-04-15 02:00:00 to 1992-04-15 01:00:00 is 60 minutes.
1992-04-15 02:00:00 to 1992-04-15 00:00:00 is 120 minutes.
1992-04-15 02:00:00 to 1992-04-14 23:00:00 is 180 minutes.
1992-04-15 00:00:00 to 1992-04-14 23:00:00 is 60 minutes.
1991-05-14 02:00:00 to 1991-05-14 01:00:00 is 60 minutes.
1991-05-14 02:00:00 to 1991-05-14 00:00:00 is 120 minutes.
1991-05-14 02:00:00 to 1991-05-13 23:00:00 is 180 minutes.
1991-05-14 00:00:00 to 1991-05-13 23:00:00 is 60 minutes.
1992-04-15 02:00:00 to 1992-04-15 01:00:00 is 60 minutes.
1992-04-15 02:00:00 to 1992-04-15 00:00:00 is 120 minutes.
1992-04-15 02:00:00 to 1992-04-14 23:00:00 is 180 minutes.
1992-04-15 00:00:00 to 1992-04-14 23:00:00 is 60 minutes.

复制代码

feng2371 · 发表于 2008-1-4 15:31

努力学习

cauc_dg · 发表于 2008-1-4 16:01

学习了~

ppbear0404 · 发表于 2008-1-4 18:51

原帖由 iooyoo 于 2008-1-4 09:20 发表
回去试了一下，好像不是，这个时间点有点问题，不知道楼主怎么试出来这个的

这个问题是偶然遇到的，一开始是将一个系统从weblogic移植到jboss上，在weblogic上时jdk是1.4，jboss用的是1.5，测试时发现了一个日期转换时有问题。后来写了一个程序，将0001-01-01到9999-12-31之间的所有日期都转换一下，结果发现有几个日期在转换时会报错。这几个日期的时分秒不能为00:00:00，其他的都可以。

今天又看了看1.4.2_12和1.5.0_12的源代码，发现类SimpleDateFormat中的parse()方法有些变化，不知道是不是这个原因导致了找个问题的发生。

iooyoo · 发表于 2008-1-4 20:11

1.4多了一个calendar.set(Calendar.HOUR, 0)
这个应该不是原因

1.4.2_15 和 1.5.0_12 这个时间点都有问题

seraphin · 发表于 2008-1-4 23:40

到sun里面找了一下，
http://bugs.sun.com/bugdatabase/ ... rd=SimpleDateFormat
SimpleDateFormat的bug report list

seraphin · 发表于 2008-1-4 23:42

还真不少

greenflute · 发表于 2008-1-5 03:18

原帖由 seraphin 于 2008-1-4 23:40 发表
到sun里面找了一下，
http://bugs.sun.com/bugdatabase/search.do?process=1&category=&bugStatus=&subcategory=&type=&keyword=SimpleDateFormat
SimpleDateFormat的bug report list