In XmlConfigurationProvider, the field loadedFileUrls contains the xml files loaded. The loaded files will be checked if they are modified for configuration reloading.
But in method private List<Document> loadConfigurationFiles(String fileName, Element includeElement), after the while (urls.hasNext()) loop, the variable url is assigned by the last one of urls with same file name.
So when loadedFileUrls.add(url.toString()); is called in the for (Document doc : docs) loop, only THE LAST ONE is added to loadedFileUrls.
I wrote a demo. I set <constant name="struts.configuration.xml.reload" value="true"/>
. I wrote two configuration files: struts-plugin.xml and struts-biz.xml in my web project. I use struts plugins such as struts-spring-plugin, struts-json-plugin and so on.
The reloading works when I changed the file struts-biz.xml in my project. But it does not work when I changed struts-plugin.xml in my project. I debug XmlConfigurationProvider and see only the struts-plugin.xml in struts-spring-plugin is contained in loadedFileUrls.
I tried to fix it by moving the loadedFileUrls.add(url.toString()); into the while (urls.hasNext()) loop. I send a pull request in github: https://github.com/apache/struts/pull/6, and I test it running well.