Thread: [Springframework-developer] non-String keys for map entries

Brought to you by: colins, jhoeller, johnsonr, robharrop, trevormarshall

springframework-developer

[Springframework-developer] non-String keys for map entries

From: <jue...@we...> - 2004-04-27 09:22:32

A colleague of mine just suggested that <entry> tags in XML bean =
definitions should also support non-String keys: After all, a =
java.util.Map can take any Object as key.

So instead of just the current:

<map>
  <entry key=3D"myKey">
    <ref bean=3D"myTarget"/>
  </entry>
</map>

We could also support something like the following:

<map>
  <entry>
    <key>
      <ref bean=3D"myKey"/>
    </key>
    <ref bean=3D"myTarget"/>
  </entry>
</map>

The problem is the syntax: It looks odd to have the <ref> Map value at =
the same level as the <key> subtag, with the latter having a nested =
<ref> again...

Any ideas?

Juergen


DI J=FCrgen H=F6ller
Senior System Architect
______________________________________

werk3ATS - division systementwicklung
werk3AT informations- und mediensysteme

europaplatz 4
A - 4020 linz

t.  +43 (0) 732 71 65 29 502
f.  +43 (0) 732 71 65 29 3
mailto:jue...@we...
http://www.werk3at.com
______________________________________
werk3ATS - WIR ENTWICKELN ERFOLG

Re: [Springframework-developer] non-String keys for map entries

From: Darren D. <da...@da...> - 2004-04-27 09:49:06

=2D----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On Tuesday 27 April 2004 10:21, j=FCrgen h=F6ller [werk3AT] wrote:
> A colleague of mine just suggested that <entry> tags in XML bean
> definitions should also support non-String keys: After all, a
> java.util.Map can take any Object as key.
>
> So instead of just the current:
>
> <map>
>   <entry key=3D"myKey">
>     <ref bean=3D"myTarget"/>
>   </entry>
> </map>
>
> We could also support something like the following:
>
> <map>
>   <entry>
>     <key>
>       <ref bean=3D"myKey"/>
>     </key>
>     <ref bean=3D"myTarget"/>
>   </entry>
> </map>
>
> The problem is the syntax: It looks odd to have the <ref> Map value at
> the same level as the <key> subtag, with the latter having a nested <ref>
> again...
>
> Any ideas?


<map>
  <!-- as now: String key -->
  <entry key=3D"myKey">
    <ref bean=3D"myTarget"/>
  </entry>
</map>


1.  consistent DTD
<map>
  <!-- kludgy..? symbolised bean reference -->
  <entry key=3D"@myBean">
    <ref bean=3D"myTarget"/>
  </entry>
</map>

2.  add ref to DTD attr list for map/entry
<map>
  <entry ref=3D"myBean">
    <ref bean=3D"myTarget"/>
  </entry>
</map>

Both suffer from losing the ability to declare 'local' or 'bean' but that=20
might not matter since neither may be capable of being validated via DTD=20
anyway - I'm no DTD expert.

Both are backward compatible though - if we go with <key> as an element=20
rather than an attribute, existing context definitions will break won't=20
they (unless the String version remains as an attribute which would be=20
somewhat confusing I think)

I wonder though what the use case would be.  I think using objects other=20
than strings as map keys is a common requirement in application code, but=20
in setting up a context?  I'm not sure - did your colleague have a=20
particular scenario in mind that could better be handled with such a=20
change, or was it a discussion item?  It'd be interesting to know!

=2D --=20

Darren Davison
Public Key: http://www.davison.uk.net/key.jsp
=2D----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (GNU/Linux)

iD8DBQFAjiyJKLMLAN01aw0RAp1ZAJ47umxiqboVg9lju9Dnn/Tznv8F4QCeKBCP
oHLwMJQ52Xe8pDxeWFeg+cI=3D
=3Ds02n
=2D----END PGP SIGNATURE-----

RE: [Springframework-developer] non-String keys for map entries

From: Alef A. <al...@jt...> - 2004-04-27 10:21:00

> 2.  add ref to DTD attr list for map/entry
> <map>
>   <entry ref="myBean">
>     <ref bean="myTarget"/>
>   </entry>
> </map>
> 
> Both suffer from losing the ability to declare 'local' or 'bean' but that
> might not matter since neither may be capable of being validated via DTD
> anyway - I'm no DTD expert.

I like this one, but for consistency purposes, I'd add the local and bean
anyway, even if no DTD checking is possible (but it IS as far as I know).

So:

<map>
	<entry bean="myBean">
		<ref bean="bla"/>
	</entry>
	<entry local="myBean">
		<ref bean="bla"/>
	</entry>
</map>

Alef

Re: [Springframework-developer] non-String keys for map entries

From: Colin S. <col...@ex...> - 2004-04-27 13:58:47

I agree it would be very good to have. I've been hit a few times by the=20
lack.

I am ok with your syntax, given that probably most of the uses will=20
still be the simple case. An alternative would be to have another kind=20
of entry allowed

<map>
  <complexentry>
    <key>
      <ref bean=3D"myKey"/>
    </key>
    <value>
      <ref bean=3D"myTarget"/>
    </value>
  </complexentry>
</map>

'complexentry' is just a name I came up with now. I don't really like it=20
or think it that suitable...

Colin


j=FCrgen h=F6ller [werk3AT] wrote:

>A colleague of mine just suggested that <entry> tags in XML bean definit=
ions should also support non-String keys: After all, a java.util.Map can =
take any Object as key.
>
>So instead of just the current:
>
><map>
>  <entry key=3D"myKey">
>    <ref bean=3D"myTarget"/>
>  </entry>
></map>
>
>We could also support something like the following:
>
><map>
>  <entry>
>    <key>
>      <ref bean=3D"myKey"/>
>    </key>
>    <ref bean=3D"myTarget"/>
>  </entry>
></map>
>
>The problem is the syntax: It looks odd to have the <ref> Map value at t=
he same level as the <key> subtag, with the latter having a nested <ref> =
again...
>
>Any ideas?
>
>Juergen
>
>
>DI J=FCrgen H=F6ller
>Senior System Architect
>______________________________________
>
>werk3ATS - division systementwicklung
>werk3AT informations- und mediensysteme
>
>europaplatz 4
>A - 4020 linz
>
>t.  +43 (0) 732 71 65 29 502
>f.  +43 (0) 732 71 65 29 3
>mailto:jue...@we...
>http://www.werk3at.com
>______________________________________
>werk3ATS - WIR ENTWICKELN ERFOLG
>
>
>-------------------------------------------------------
>This SF.net email is sponsored by: The Robotic Monkeys at ThinkGeek
>For a limited time only, get FREE Ground shipping on all orders of $35
>or more. Hurry up and shop folks, this offer expires April 30th!
>http://www.thinkgeek.com/freeshipping/?cpg=12297
>_______________________________________________
>Springframework-developer mailing list
>Spr...@li...
>https://lists.sourceforge.net/lists/listinfo/springframework-developer
> =20
>

Re: [Springframework-developer] non-String keys for map entries

From: <tho...@tr...> - 2004-04-27 14:50:48

I too think this would be valuable.

I'd like to keep it simple.  The following seems to me the most consistent with
the current syntax and with the Map interface itself:

<map>
  <entry keyref="myBean">
    <ref bean="myTarget"/>
  </entry>
</map>

or 

<map>
  <entry>
    <key>
      <ref bean="myKeyBean"/>
    </key>
    <value>
      <ref bean="myTargetBean"/>
    </value>
  </entry>
</map>

This should also be valid, but I would not recommend using it:

<map>
  <entry>
    <key>
      <ref bean="myKeyBean"/>
    </key>
    <ref bean="myTargetBean"/>
  </entry>
</map>


Thomas



Quoting Colin Sampaleanu <col...@ex...>:

> I agree it would be very good to have. I've been hit a few times by the 
> lack.
> 
> I am ok with your syntax, given that probably most of the uses will 
> still be the simple case. An alternative would be to have another kind 
> of entry allowed
> 
> <map>
>   <complexentry>
>     <key>
>       <ref bean="myKey"/>
>     </key>
>     <value>
>       <ref bean="myTarget"/>
>     </value>
>   </complexentry>
> </map>
> 
> 'complexentry' is just a name I came up with now. I don't really like it 
> or think it that suitable...
> 
> Colin
> 
> 
> jürgen höller [werk3AT] wrote:
> 
> >A colleague of mine just suggested that <entry> tags in XML bean definitions
> should also support non-String keys: After all, a java.util.Map can take any
> Object as key.
> >
> >So instead of just the current:
> >
> ><map>
> >  <entry key="myKey">
> >    <ref bean="myTarget"/>
> >  </entry>
> ></map>
> >
> >We could also support something like the following:
> >
> ><map>
> >  <entry>
> >    <key>
> >      <ref bean="myKey"/>
> >    </key>
> >    <ref bean="myTarget"/>
> >  </entry>
> ></map>
> >
> >The problem is the syntax: It looks odd to have the <ref> Map value at the
> same level as the <key> subtag, with the latter having a nested <ref>
> again...
> >
> >Any ideas?
> >
> >Juergen
> >
> >
> >DI Jürgen Höller
> >Senior System Architect
> >______________________________________
> >
> >werk3ATS - division systementwicklung
> >werk3AT informations- und mediensysteme
> >
> >europaplatz 4
> >A - 4020 linz
> >
> >t.  +43 (0) 732 71 65 29 502
> >f.  +43 (0) 732 71 65 29 3
> >mailto:jue...@we...
> >http://www.werk3at.com
> >______________________________________
> >werk3ATS - WIR ENTWICKELN ERFOLG
> >
> >
> >-------------------------------------------------------
> >This SF.net email is sponsored by: The Robotic Monkeys at ThinkGeek
> >For a limited time only, get FREE Ground shipping on all orders of $35
> >or more. Hurry up and shop folks, this offer expires April 30th!
> >http://www.thinkgeek.com/freeshipping/?cpg297
> >_______________________________________________
> >Springframework-developer mailing list
> >Spr...@li...
> >https://lists.sourceforge.net/lists/listinfo/springframework-developer
> >  
> >
> 
> 
> 
> -------------------------------------------------------
> This SF.net email is sponsored by: The Robotic Monkeys at ThinkGeek
> For a limited time only, get FREE Ground shipping on all orders of $35
> or more. Hurry up and shop folks, this offer expires April 30th!
> http://www.thinkgeek.com/freeshipping/?cpg297
> _______________________________________________
> Springframework-developer mailing list
> Spr...@li...
> https://lists.sourceforge.net/lists/listinfo/springframework-developer
>

Re: [Springframework-developer] non-String keys for map entries

From: Les A. H. <le...@ha...> - 2004-04-27 23:23:21

I think the following two are the best candidates:

<map>
  <entry>
    <key bean=3D"myBean"/>     <!-- or <key local=3D"myBean"/>     -->
    <value bean=3D"myTarget"/> <!-- or <value local=3D"myTarget"/> -->
  </entry>
</map>

or (verbose version of above):

<map>
  <entry>
    <key><ref bean=3D"myBean"/></key>
    <value><ref bean=3D"myTarget"/></value>
  </entry>
</map>


I really like the first version, and I think it is the most readable.  I don=
't
know if it would break backwards compatibility though.  Whatever the decisio=
n I
think the most important factor (logically) is that the key and value elemen=
ts
remain xml peers to accurately reflect the Object structure.

So, the following (IMO) would not be a good candidate as it isn't readable a=
s
the first two and doesn't visually reflect the actual object structure of
Map.Entry :

<map>
  <entry key=3D"myKey">
    <ref bean=3D"myTarget"/>
  </entry>
</map>


Les




Quoting tho...@tr...:

> I too think this would be valuable.
>
> I'd like to keep it simple.  The following seems to me the most consistent
> with
> the current syntax and with the Map interface itself:
>
> <map>
>   <entry keyref=3D"myBean">
>     <ref bean=3D"myTarget"/>
>   </entry>
> </map>
>
> or
>
> <map>
>   <entry>
>     <key>
>       <ref bean=3D"myKeyBean"/>
>     </key>
>     <value>
>       <ref bean=3D"myTargetBean"/>
>     </value>
>   </entry>
> </map>
>
> This should also be valid, but I would not recommend using it:
>
> <map>
>   <entry>
>     <key>
>       <ref bean=3D"myKeyBean"/>
>     </key>
>     <ref bean=3D"myTargetBean"/>
>   </entry>
> </map>
>
>
> Thomas
>
>
>
> Quoting Colin Sampaleanu <col...@ex...>:
>
> > I agree it would be very good to have. I've been hit a few times by the
> > lack.
> >
> > I am ok with your syntax, given that probably most of the uses will
> > still be the simple case. An alternative would be to have another kind
> > of entry allowed
> >
> > <map>
> >   <complexentry>
> >     <key>
> >       <ref bean=3D"myKey"/>
> >     </key>
> >     <value>
> >       <ref bean=3D"myTarget"/>
> >     </value>
> >   </complexentry>
> > </map>
> >
> > 'complexentry' is just a name I came up with now. I don't really like it
> > or think it that suitable...
> >
> > Colin
> >
> >
> > j=C3=BCrgen h=C3=B6ller [werk3AT] wrote:
> >
> > >A colleague of mine just suggested that <entry> tags in XML bean
> definitions
> > should also support non-String keys: After all, a java.util.Map can take
> any
> > Object as key.
> > >
> > >So instead of just the current:
> > >
> > ><map>
> > >  <entry key=3D"myKey">
> > >    <ref bean=3D"myTarget"/>
> > >  </entry>
> > ></map>
> > >
> > >We could also support something like the following:
> > >
> > ><map>
> > >  <entry>
> > >    <key>
> > >      <ref bean=3D"myKey"/>
> > >    </key>
> > >    <ref bean=3D"myTarget"/>
> > >  </entry>
> > ></map>
> > >
> > >The problem is the syntax: It looks odd to have the <ref> Map value at =
the
> > same level as the <key> subtag, with the latter having a nested <ref>
> > again...
> > >
> > >Any ideas?
> > >
> > >Juergen
> > >
> > >
> > >DI J=C3=BCrgen H=C3=B6ller
> > >Senior System Architect
> > >______________________________________
> > >
> > >werk3ATS - division systementwicklung
> > >werk3AT informations- und mediensysteme
> > >
> > >europaplatz 4
> > >A - 4020 linz
> > >
> > >t.  +43 (0) 732 71 65 29 502
> > >f.  +43 (0) 732 71 65 29 3
> > >mailto:jue...@we...
> > >http://www.werk3at.com
> > >______________________________________
> > >werk3ATS - WIR ENTWICKELN ERFOLG
> > >
> > >
> > >-------------------------------------------------------
> > >This SF.net email is sponsored by: The Robotic Monkeys at ThinkGeek
> > >For a limited time only, get FREE Ground shipping on all orders of $35
> > >or more. Hurry up and shop folks, this offer expires April 30th!
> > >http://www.thinkgeek.com/freeshipping/?cpg=12297
> > >_______________________________________________
> > >Springframework-developer mailing list
> > >Spr...@li...
> > >https://lists.sourceforge.net/lists/listinfo/springframework-developer
> > >
> > >
> >
> >
> >
> > -------------------------------------------------------
> > This SF.net email is sponsored by: The Robotic Monkeys at ThinkGeek
> > For a limited time only, get FREE Ground shipping on all orders of $35
> > or more. Hurry up and shop folks, this offer expires April 30th!
> > http://www.thinkgeek.com/freeshipping/?cpg=12297
> > _______________________________________________
> > Springframework-developer mailing list
> > Spr...@li...
> > https://lists.sourceforge.net/lists/listinfo/springframework-developer
> >
>
>
>
>
>
> -------------------------------------------------------
> This SF.net email is sponsored by: The Robotic Monkeys at ThinkGeek
> For a limited time only, get FREE Ground shipping on all orders of $35
> or more. Hurry up and shop folks, this offer expires April 30th!
> http://www.thinkgeek.com/freeshipping/?cpg=3D12297
> _______________________________________________
> Springframework-developer mailing list
> Spr...@li...
> https://lists.sourceforge.net/lists/listinfo/springframework-developer
>

Re: [Springframework-developer] non-String keys for map entries

From: Colin S. <col...@ex...> - 2004-04-28 03:03:44

btw Thomas, a few people have suggested a variation of your first choice 
below. However, while that covers having a key that's a bean reference, 
it doesn't cover the case where it's defined inline (as a value or other 
type)...


tho...@tr... wrote:

>I too think this would be valuable.
>
>I'd like to keep it simple.  The following seems to me the most consistent with
>the current syntax and with the Map interface itself:
>
><map>
>  <entry keyref="myBean">
>    <ref bean="myTarget"/>
>  </entry>
></map>
>
>or 
>
><map>
>  <entry>
>    <key>
>      <ref bean="myKeyBean"/>
>    </key>
>    <value>
>      <ref bean="myTargetBean"/>
>    </value>
>  </entry>
></map>
>
>This should also be valid, but I would not recommend using it:
>
><map>
>  <entry>
>    <key>
>      <ref bean="myKeyBean"/>
>    </key>
>    <ref bean="myTargetBean"/>
>  </entry>
></map>
>
>
>Thomas
>
>
>
>Quoting Colin Sampaleanu <col...@ex...>:
>
>  
>
>>I agree it would be very good to have. I've been hit a few times by the 
>>lack.
>>
>>I am ok with your syntax, given that probably most of the uses will 
>>still be the simple case. An alternative would be to have another kind 
>>of entry allowed
>>
>><map>
>>  <complexentry>
>>    <key>
>>      <ref bean="myKey"/>
>>    </key>
>>    <value>
>>      <ref bean="myTarget"/>
>>    </value>
>>  </complexentry>
>></map>
>>
>>'complexentry' is just a name I came up with now. I don't really like it 
>>or think it that suitable...
>>
>>Colin
>>
>>
>>jürgen höller [werk3AT] wrote:
>>
>>    
>>
>>>A colleague of mine just suggested that <entry> tags in XML bean definitions
>>>      
>>>
>>should also support non-String keys: After all, a java.util.Map can take any
>>Object as key.
>>    
>>
>>>So instead of just the current:
>>>
>>><map>
>>> <entry key="myKey">
>>>   <ref bean="myTarget"/>
>>> </entry>
>>></map>
>>>
>>>We could also support something like the following:
>>>
>>><map>
>>> <entry>
>>>   <key>
>>>     <ref bean="myKey"/>
>>>   </key>
>>>   <ref bean="myTarget"/>
>>> </entry>
>>></map>
>>>
>>>The problem is the syntax: It looks odd to have the <ref> Map value at the
>>>      
>>>
>>same level as the <key> subtag, with the latter having a nested <ref>
>>again...
>>    
>>
>>>Any ideas?
>>>
>>>Juergen
>>>      
>>>

RE: [Springframework-developer] non-String keys for map entries

From: James C. <jim...@do...> - 2004-04-27 16:37:48

I too like Colin's proposed syntax. It would be slightly more in line =
with
the Java Map to change <complexentry> to <mapentry>.

> -----Original Message-----
> From: spr...@li...
> [mailto:spr...@li...] On =
Behalf
> Of Colin Sampaleanu
> Sent: Tuesday, April 27, 2004 9:59 AM
> To: spr...@li...
> Subject: Re: [Springframework-developer] non-String keys for map =
entries
>=20
> I agree it would be very good to have. I've been hit a few times by =
the
> lack.
>=20
> I am ok with your syntax, given that probably most of the uses will
> still be the simple case. An alternative would be to have another kind
> of entry allowed
>=20
> <map>
>   <complexentry>
>     <key>
>       <ref bean=3D"myKey"/>
>     </key>
>     <value>
>       <ref bean=3D"myTarget"/>
>     </value>
>   </complexentry>
> </map>
>=20
> 'complexentry' is just a name I came up with now. I don't really like =
it
> or think it that suitable...
>=20
> Colin
>=20
>=20
> j=FCrgen h=F6ller [werk3AT] wrote:
>=20
> >A colleague of mine just suggested that <entry> tags in XML bean
> definitions should also support non-String keys: After all, a
> java.util.Map can take any Object as key.
> >
> >So instead of just the current:
> >
> ><map>
> >  <entry key=3D"myKey">
> >    <ref bean=3D"myTarget"/>
> >  </entry>
> ></map>
> >
> >We could also support something like the following:
> >
> ><map>
> >  <entry>
> >    <key>
> >      <ref bean=3D"myKey"/>
> >    </key>
> >    <ref bean=3D"myTarget"/>
> >  </entry>
> ></map>
> >
> >The problem is the syntax: It looks odd to have the <ref> Map value =
at
> the same level as the <key> subtag, with the latter having a nested =
<ref>
> again...
> >
> >Any ideas?
> >
> >Juergen
> >
> >
> >DI J=FCrgen H=F6ller
> >Senior System Architect
> >______________________________________
> >
> >werk3ATS - division systementwicklung
> >werk3AT informations- und mediensysteme
> >
> >europaplatz 4
> >A - 4020 linz
> >
> >t.  +43 (0) 732 71 65 29 502
> >f.  +43 (0) 732 71 65 29 3
> >mailto:jue...@we...
> >http://www.werk3at.com
> >______________________________________
> >werk3ATS - WIR ENTWICKELN ERFOLG
> >
> >
> >-------------------------------------------------------
> >This SF.net email is sponsored by: The Robotic Monkeys at ThinkGeek
> >For a limited time only, get FREE Ground shipping on all orders of =
$35
> >or more. Hurry up and shop folks, this offer expires April 30th!
> >http://www.thinkgeek.com/freeshipping/?cpg=12297
> >_______________________________________________
> >Springframework-developer mailing list
> >Spr...@li...
> =
>https://lists.sourceforge.net/lists/listinfo/springframework-developer
> >
> >
>=20
>=20
>=20
> -------------------------------------------------------
> This SF.net email is sponsored by: The Robotic Monkeys at ThinkGeek
> For a limited time only, get FREE Ground shipping on all orders of $35
> or more. Hurry up and shop folks, this offer expires April 30th!
> http://www.thinkgeek.com/freeshipping/?cpg=12297
> _______________________________________________
> Springframework-developer mailing list
> Spr...@li...
> https://lists.sourceforge.net/lists/listinfo/springframework-developer