We have an Action class named 'Index' immediately under com.example.common.action and is annotated @ParentPackage('default') which is declared in package directive in struts.xml and has "/" for its namespace and extends "struts-default". It also declares @Result so that it responses with jsp files corresponding the string values returned by its execute() method.
In our struts.xml, the following struts setting is configured along with other necessary configurations that are needed for convention-plugin.
<constant name="struts.action.extension" value=","/>
When accessing /my_context/none_existing_path, the request apparently hits this Index class and the contents of the jsp declared in the Index's @Result section gets returned.
However, if we provide /my_context/, we receive the following error:
HTTP Status 404-There is no Action mapped for namespace[/] and action name  associated with context path [/my_context].
We want to know the reason why accessing /my_context/none_existing_path, where none_existing_path has no matching action, can fallback to Index class, but error is returned when when the URL requested is just /my_context/.
Currently, our convention-plugin settings are declared as follows:
<constant name="struts.convention.package.locators.basePackage" value="com.example"/>
<constant name="struts.convention.package.locators" value="action"/>
Strangely, if we changed the value of the struts.convention.package.locators.basePackage to
com.example.common and narrowed the search scope of the aforementioned Index file, requesting /my_context/ displayed the content of the jsps declared in @Result section of the Index class. However, as our action classes are distributed throughout the com.example.[a-z].action packages, where [a-z] represents the large volume of directories we have in our package structure, we cannot use this trick as a workaround. We have also tried placing index.jsp at the top level of the class path, and have the index.jsp redirect to /my_context/index, which worked but not what we want. Could this be a bug?
We appreciate your responses.
Thank you in advance.