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From: Peter B. <pet...@ho...> - 2005-10-19 09:37:09
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Hello.
Would it make sense to add key-class and value-class attributes to the
<map> element, and feed the strings in the key/value elements (or
attributes) to the appropriate PropertyEditor, to allow setting key and
value of the correct class when using maps with generics?
For example, consider this example:
public Map<Locale, String> getHeadsOfState() { ... }
configured like this:
<property name="headsOfState">
<map key-class="java.util.Locale" value-class="java.lang.String">
<entry key="en_US" value="George W. Bush"/>
<entry key="en_GB" value="Tony Blair"/>
<entry key="sv_SE" value="Göran Persson"/>
</map>
</property>
I've glanced at modifying the xml parsing and subclassing or modifying
MapFactoryBean, but I thought I'd ask here first if it's possible to do
this any other way, or if it's a bad idea altogether.
What do you think?
/Peter Backlund
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From: Rob H. <rob...@in...> - 2005-10-22 15:53:06
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That's not a bad idea - can you raise an JIRA issue for this? Also, in
Spring 1.3 we will actually autodetect the element types when using
generics definitions like you have here so you won't need to specify the
element types.
Rob
Peter Backlund wrote:
>Hello.
>
>Would it make sense to add key-class and value-class attributes to the
><map> element, and feed the strings in the key/value elements (or
>attributes) to the appropriate PropertyEditor, to allow setting key and
>value of the correct class when using maps with generics?
>
>For example, consider this example:
>
>public Map<Locale, String> getHeadsOfState() { ... }
>
>configured like this:
>
><property name="headsOfState">
> <map key-class="java.util.Locale" value-class="java.lang.String">
> <entry key="en_US" value="George W. Bush"/>
> <entry key="en_GB" value="Tony Blair"/>
> <entry key="sv_SE" value="Göran Persson"/>
> </map>
></property>
>
>I've glanced at modifying the xml parsing and subclassing or modifying
>MapFactoryBean, but I thought I'd ask here first if it's possible to do
>this any other way, or if it's a bad idea altogether.
>
>What do you think?
>
>/Peter Backlund
>
>
>
>
>
>-------------------------------------------------------
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--
Rob Harrop
Principal Consultant
Interface21 - Spring Services from the Source
http://www.springframework.com
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From: Peter B. <pet...@ho...> - 2005-10-22 18:52:44
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On Sat, 2005-10-22 at 16:52 +0100, Rob Harrop wrote:
> That's not a bad idea - can you raise an JIRA issue for this? Also, in
> Spring 1.3 we will actually autodetect the element types when using
> generics definitions like you have here so you won't need to specify the
> element types.
Sure, but would that really be necessary if you can autodetect it in
1.3? Besides, is it possible to detect generics definitions in bytecode?
I was under the impression that it wasn't possible, or will it require
processing of the corresponding source code?
/Peter
>
> Rob
>
> Peter Backlund wrote:
>
> >Hello.
> >
> >Would it make sense to add key-class and value-class attributes to the
> ><map> element, and feed the strings in the key/value elements (or
> >attributes) to the appropriate PropertyEditor, to allow setting key and
> >value of the correct class when using maps with generics?
> >
> >For example, consider this example:
> >
> >public Map<Locale, String> getHeadsOfState() { ... }
> >
> >configured like this:
> >
> ><property name="headsOfState">
> > <map key-class="java.util.Locale" value-class="java.lang.String">
> > <entry key="en_US" value="George W. Bush"/>
> > <entry key="en_GB" value="Tony Blair"/>
> > <entry key="sv_SE" value="Göran Persson"/>
> > </map>
> ></property>
> >
> >I've glanced at modifying the xml parsing and subclassing or modifying
> >MapFactoryBean, but I thought I'd ask here first if it's possible to do
> >this any other way, or if it's a bad idea altogether.
> >
> >What do you think?
> >
> >/Peter Backlund
> >
> >
> >
> >
> >
> >-------------------------------------------------------
> >This SF.Net email is sponsored by:
> >Power Architecture Resource Center: Free content, downloads, discussions,
> >and more. http://solutions.newsforge.com/ibmarch.tmpl
> >_______________________________________________
> >Springframework-developer mailing list
> >Spr...@li...
> >https://lists.sourceforge.net/lists/listinfo/springframework-developer
> >
> >
>
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From: Colin S. <col...@ex...> - 2005-10-23 12:22:55
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My understanding is that Generics-based types map to completely standard
(non-Generics) byte code for those types. So if you have a List<String>
and you pass that to somebody, at the bytecode level it's a completely
normal List. This is part of the reason why Generics in Java are
somewhat half-assed; some of the limitations could have been removed if
the basic class related bytcode had had enhancements to support some
concepts needed for templating.
Here's some info on this aspect:
http://www.langer.camelot.de/GenericsFAQ/FAQSections/TechnicalDetails.html#How%20does%20the%20compiler%20translate%20Java%20generics?
On the other hand, when it comes to method signatures, my understanding
is that the bounding information is available through reflection. So you
can tell that a method takes a List<String> and not a List. I'm not 100%
sure on this (and confirmation by anybody would be good), but I presume
this is what Rob is basing his statement below on.
Regards,
Colin
Peter Backlund wrote:
>On Sat, 2005-10-22 at 16:52 +0100, Rob Harrop wrote:
>
>
>>That's not a bad idea - can you raise an JIRA issue for this? Also, in
>>Spring 1.3 we will actually autodetect the element types when using
>>generics definitions like you have here so you won't need to specify the
>>element types.
>>
>>
>
>Sure, but would that really be necessary if you can autodetect it in
>1.3? Besides, is it possible to detect generics definitions in bytecode?
>I was under the impression that it wasn't possible, or will it require
>processing of the corresponding source code?
>
>/Peter
>
>
>
>>Rob
>>
>>Peter Backlund wrote:
>>
>>
>>
>>>Hello.
>>>
>>>Would it make sense to add key-class and value-class attributes to the
>>><map> element, and feed the strings in the key/value elements (or
>>>attributes) to the appropriate PropertyEditor, to allow setting key and
>>>value of the correct class when using maps with generics?
>>>
>>>For example, consider this example:
>>>
>>>public Map<Locale, String> getHeadsOfState() { ... }
>>>
>>>configured like this:
>>>
>>><property name="headsOfState">
>>> <map key-class="java.util.Locale" value-class="java.lang.String">
>>> <entry key="en_US" value="George W. Bush"/>
>>> <entry key="en_GB" value="Tony Blair"/>
>>> <entry key="sv_SE" value="Göran Persson"/>
>>> </map>
>>></property>
>>>
>>>I've glanced at modifying the xml parsing and subclassing or modifying
>>>MapFactoryBean, but I thought I'd ask here first if it's possible to do
>>>this any other way, or if it's a bad idea altogether.
>>>
>>>What do you think?
>>>
>>>/Peter Backlund
>>>
>>>
>>>
>>>
>>>
>>>-------------------------------------------------------
>>>This SF.Net email is sponsored by:
>>>Power Architecture Resource Center: Free content, downloads, discussions,
>>>and more. http://solutions.newsforge.com/ibmarch.tmpl
>>>_______________________________________________
>>>Springframework-developer mailing list
>>>Spr...@li...
>>>https://lists.sourceforge.net/lists/listinfo/springframework-developer
>>>
>>>
>>>
>>>
>
>
>
>
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