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Re: Problem with JDBC driver and MySQL date_format function

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On 05/16/2011 08:46 AM, John B. Matthews wrote:
> In article<iqqdg9$lj7$1@news.albasani.net>, Lew<noone@lewscanon.com>
> wrote:
>
>> On 05/16/2011 01:35 AM, Stanimir Stamenkov wrote:
>>> Sun, 15 May 2011 19:51:49 -0400, /John B. Matthews/:
>>>> In article<939s7hFsqnU1@mid.individual.net>, Hans Castorp wrote:
>>>>> Jens Riedel wrote on 13.05.2011 08:11:
>>>>>
>>>>>> Since I updated my mysql driver version 3 to version 5
>>>>>> (mysql-connector-java-5.1.7-bin.jar) I get funny strings like
>>>>>> "[B@b57546" when I format datetime columns with the date_format
>>>>>> function instead of the correct formatted date string.
>>>>>
>>>>> That sure looks like the default toString() output of
>>>>> java.lang.Object
>>>>
>>>> No, java.lang.Object looks like this: java.lang.Object@771c8a71
>>>
>>> That looks like the output of java.lang.Object.toString() invoked
>>> on a byte[] instance:
>>>
>>> getClass().getName() + '@' + Integer.toHexString(hashCode())
>>>
>>> http://download.oracle.com/javase/6/docs/api/java/lang/Object.html#toString%28%29
>>>
>>> http://download.oracle.com/javase/6/docs/api/java/lang/Class.html#getName%28%29
>>
>> You guys are talking at cross purposes because you're using different
>> definitions of 'java.lang.Object.toString()'.  Stanimir means the
>> method as implemented in 'Object' and not overridden by 'byte[]'.
>> John means the method as applied to 'Object' itself.  Both of you are
>> correct.  Now you can stop arguing.
>
> Stanimir: I never noticed the correspondence between the numeric
> portion and the result from hashCode(), but it's right there in the
> source, as quoted in the API. Thanks.

Note the advice that the hash code "is typically implemented by converting the 
internal address of the object into an integer, but this implementation 
technique is not required by the JavaTM programming language."  Either way, 
whatever the hash code is will be part of the base 'Object#toString()'.

> Lew: This looks like another good argument for continually reviewing
> APIs, even familiar ones.

I may be (am) out of shape now, but years ago when I took karate, every 
instructor always made us relearn the basics several times a year.  Same thing 
in music - every musician I know who's any good tells me they spend hours 
daily just practicing scales.  Pro athletes are always drilling the basics 
over and over and over.  It is a concomitant to expertise in any skill activity.

-- 
Lew
Honi soit qui mal y pense.
http://upload.wikimedia.org/wikipedia/commons/c/cf/Friz.jpg

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Problem with JDBC driver and MySQL date_format function Jens Riedel <JensRie@gmx.de> - 2011-05-13 08:11 +0200
  Re: Problem with JDBC driver and MySQL date_format function "John B. Matthews" <nospam@nospam.invalid> - 2011-05-14 18:19 -0400
    Re: Problem with JDBC driver and MySQL date_format function Lew <noone@lewscanon.com> - 2011-05-15 06:59 -0400
  Re: Problem with JDBC driver and MySQL date_format function Hans Castorp <REWYRLXHEGHO@spammotel.com> - 2011-05-15 13:37 +0200
    Re: Problem with JDBC driver and MySQL date_format function "John B. Matthews" <nospam@nospam.invalid> - 2011-05-15 19:51 -0400
      Re: Problem with JDBC driver and MySQL date_format function Stanimir Stamenkov <s7an10@netscape.net> - 2011-05-16 08:35 +0300
        Re: Problem with JDBC driver and MySQL date_format function Lew <noone@lewscanon.com> - 2011-05-16 01:42 -0400
          Re: Problem with JDBC driver and MySQL date_format function "John B. Matthews" <nospam@nospam.invalid> - 2011-05-16 08:46 -0400
            Re: Problem with JDBC driver and MySQL date_format function Lew <noone@lewscanon.com> - 2011-05-16 10:23 -0400
  Re: Problem with JDBC driver and MySQL date_format function Jens Riedel <JensRie@gmx.de> - 2011-05-15 21:17 +0200

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