I have found some stranges behaviours changing the request_locale dinamically :

BEHAVIOUR 1:

***JSP code:

<ww:url id="changeLanguageURLEspanol" action="test">
      <ww:param name="request_locale">es_ES</ww:param>
  </ww:url>
   
<ww:url id="changeLanguageURLPortugues" action="test">
      <ww:param name="request_locale">pt_PT</ww:param>
  </ww:url>
    
<ww:a href="%{changeLanguageURLEspanol}">Español</ww:a>
  <ww:a href="%{changeLanguageURLPortugues}">Portugues</ww:a>

***xwork.xml file:

<action name="test" class="samples.Test">
       <interceptor-ref name="i18n"/>
        <result name="success">result.jsp</result>
</action>

works fine (produces the change of the actual language and saves the request_locale in session ) but doesn't remove the request_locale parameter
from the url, in other word,s the consecutive requests looks like this:

http://localhost:8080/Samples/ActionName.action?request_locale=pt_PT
http://localhost:8080/Samples/AnotherActionName.action?request_locale=pt_PT
http://localhost:8080/Samples/AndAnotherActionName.action?request_locale=pt_PT

BEHAVIOUR 2:

I have test it with this other jsp code obtaining the same results (with the same xwork.xml configuration file):

<a href="test.action?request_locale=es_ES">Español</a>
<a href="test.action?request_locale=pt_PT">Portugues</a>

BEHAVIOUR 3:


*** JSP file:
 
<ww:url id="changeLanguageURLEspanol" action="test?request_locale=es_ES" />
  <ww:url id="changeLanguageURLPortugues" action="test?request_locale=pt_PT" />
  
<ww:a href="%{changeLanguageURLEspanol}">Español</ww:a>
  <ww:a href="%{changeLanguageURLPortugues}">Portugues</ww:a>

*** xwork.xml configuration file: Same

The result:

1.- if I click on Portugues:
http://localhost:8080/Samples/test.action?request_locale=pt_PT

It changes the language correctly

2.- then if I click on Español:
http://localhost:8080/Samples/test.action?request_locale=es_ES&request_locale=pt_PT

It doesnt change the language

3.- and if I click on Portugues again:
http://localhost:8080/Samples/test.action?request_locale=pt_PT&request_locale=pt_PT

It doesnt change the language

And so on

Finally, It was tested also with the completeStack

Thank you