Groups > comp.lang.java.programmer > #13082

Re: JSTL: getting a map's keys

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From	Chris Riesbeck <Chris.Riesbeck@gmail.com>
Newsgroups	comp.lang.java.programmer
Subject	Re: JSTL: getting a map's keys
Date	Tue, 20 Mar 2012 12:52:46 -0500
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On 3/20/2012 12:19 PM, Chris Riesbeck wrote:
> On 3/19/2012 6:59 PM, Daniel Pitts wrote:
>> On 3/19/12 11:15 AM, Chris Riesbeck wrote:
>>>
>>> [summary: rates is an instance of a subclass of Map that
 >>>  implements getKeys()]
>>>
>>> Why does ${rates.keys} generate nothing in these lines of JSP?
>>>
>> My guess is that ${rates.keys} is interpreted as equivalent to
>> ${rates['keys']}, so it is looking for a key of "keys", not a java bean
>> property.

Just to nail the coffin lid shut on this. The JSP EL defines name.key as 
just shorthand for name["key"]. To interpret [] expressions, JSP uses 
the first answer it gets from this chain of resolvers:

     ImplicitObjectELResolver
     registered custom ELResolvers
     MapELResolver
     ListELResolver
     ArrayELResolver
     BeanELResolver
     ScopedAttributeELResolver

 
http://docs.oracle.com/javaee/5/api/javax/servlet/jsp/JspApplicationContext.html

So the Map interpretation will always override the Bean interpretation.

Thread

JSTL: getting a map's keys Chris Riesbeck <Chris.Riesbeck@gmail.com> - 2012-03-19 13:15 -0500
  Re: JSTL: getting a map's keys Lew <lewbloch@gmail.com> - 2012-03-19 12:57 -0700
  Re: JSTL: getting a map's keys Tim Slattery <Slattery_T@bls.gov> - 2012-03-19 16:08 -0400
    Re: JSTL: getting a map's keys Chris Riesbeck <Chris.Riesbeck@gmail.com> - 2012-03-19 16:06 -0500
      Re: JSTL: getting a map's keys Chris Riesbeck <Chris.Riesbeck@gmail.com> - 2012-03-19 16:39 -0500
    Re: JSTL: getting a map's keys markspace <-@.> - 2012-03-19 15:27 -0700
  Re: JSTL: getting a map's keys Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-03-19 16:59 -0700
    Re: JSTL: getting a map's keys Chris Riesbeck <Chris.Riesbeck@gmail.com> - 2012-03-20 12:19 -0500
      Re: JSTL: getting a map's keys Chris Riesbeck <Chris.Riesbeck@gmail.com> - 2012-03-20 12:52 -0500
        Re: JSTL: getting a map's keys Lew <lewbloch@gmail.com> - 2012-03-20 11:05 -0700
          Re: JSTL: getting a map's keys Chris Riesbeck <Chris.Riesbeck@gmail.com> - 2012-03-21 13:09 -0500
            Re: JSTL: getting a map's keys Lew <noone@lewscanon.com> - 2012-03-22 07:51 -0700
              Re: JSTL: getting a map's keys Chris Riesbeck <Chris.Riesbeck@gmail.com> - 2012-03-22 12:53 -0500
                Re: JSTL: getting a map's keys Lew <lewbloch@gmail.com> - 2012-03-22 13:23 -0700
                Re: JSTL: getting a map's keys Chris Riesbeck <Chris.Riesbeck@gmail.com> - 2012-03-23 12:23 -0500
                Re: JSTL: getting a map's keys Lew <noone@lewscanon.com> - 2012-03-23 13:50 -0700
                Re: JSTL: getting a map's keys Chris Riesbeck <Chris.Riesbeck@gmail.com> - 2012-03-26 14:10 -0500
        Re: JSTL: getting a map's keys Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-03-20 11:28 -0700
        Re: JSTL: getting a map's keys markspace <-@.> - 2012-03-20 11:29 -0700
          Re: JSTL: getting a map's keys Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-03-20 12:10 -0700

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