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obtain the key of a map

nimo frey
Ranch Hand

Joined: Jun 28, 2008
Posts: 580
I have a Map:

Now, I want to get only the keys(name of the keys!!) via JSF-EL:


returns the complete map :

{key1=[], key2=[test, hello]}

How can I return the value of the keys?

For example, this does not work:
Tim Holloway
Saloon Keeper

Joined: Jun 25, 2001
Posts: 16468

You'll need to define a "keys" property on your object. Since there's no "getKeys()" method in the standard Java.util.Map collection, that means you'll need to subclass it with a class of your own that includes getKeys(). Your getKeys() method would need to invoke the Map keySet() method and present the resulting java.util.Set according to how you want it rendered on the page. Usually, you'd want to sort it, since a Set is an unordered collection.

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nimo frey
Ranch Hand

Joined: Jun 28, 2008
Posts: 580
I tried it with that, and it works (without implementing a getKey-Property)

To get the values, you can use:

I know, I should avoid using JSTL, but c:forEach works always, where ui:repeat does not work always.

Should I do it that way, when it works?
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