Parametric file inclusion in struts.xml configurations, based on properties - spring

Question

I have a web application (built on Spring, Struts 2) and I am trying to dynamically include a struts configuration file inside the main struts.xml configuration, based on a property.
Having defined, in the property file:
key=foo
I try to use it inside struts.xml:
<struts>
...
<include file="/config/struts/struts-${key}.xml" />
</struts>
To include the "struts-foo.xml" file (or another file, depending on the value).
The property file is loaded at startup by Spring, and I am able to use it inside Spring's xml files to parametrize bean definition.

Answer 1

You could leverage the Struts2 plugin framework.
You basically create a jar based project where you include all of a particular client's action mappings, support classes, etc. If you're also deploying into a Servlet 3.0 or higher container, you can also elect to include the UI artifacts inside the jar's META-INF\resources directory too for clean packaging.
Now, the contents you typically place inside the struts.xml for action mappings, you simply place inside struts-plugin.xml and place this xml file in the root of the jar file.
When the Struts2 framework starts, the jar files will be scanned, the struts-plugin.xml files will be picked up and automatically included in your application.
I use the same setup in conjunction with my maven build process so that if a client's deployment isn't suppose to include a specific feature or if a standard feature is to be customized, I can customize the action mappings from the stock ones.
In our case, the stock app is a struts-plugin based jar that gets loaded before any other jars and then subsequent feature jars are loaded to extend or override functionality. The actual WAR project has little inside it and is mainly an artifact used to deploy combinations of other project artifacts.

Answer 2

As you know you can change the struts.xml config file name, as below:
<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
<init-param>
<param-name>config</param-name>
<param-value>struts-config.xml</param-value>
</init-param>
</filter>
You can use this feature to change struts.xml dynamicly.
You need to extend the StrutsPrepareAndExecuteFilter and load your dynamic config here. Replace your new fildter with struts in web.xml.
public class MyStrutsPrepareAndExecuteFilter extends StrutsPrepareAndExecuteFilter{
#Override
protected void postInit(Dispatcher dispatcher, FilterConfig filterConfig) {
//load your config here
}
}
Please have a look at StrutsPrepareAndExecuteFilter source code. you can see how the config is loaded and you can how you can change it.
If you want to only dynamical change your application messages you can do it more easily by just calling LocalizedTextUtil.addDefaultResourceBundle ("messages/customize") in MyStrutsPrepareAndExecuteFilter