Duplicate fragment name ERROR Jetty Maven Plugin

Question

I run the jetty-maven-plugin 8.0.0M2. Works fine after startup (mvn jetty:run) . If I change a source the plugin tries to hot deploy but gets stuck because of the following error

 Duplicate fragment name: PrimeFaces for jar:file:/C:/path/to/project/webroot/WEB-INF/lib/primefaces-2.1.jar!/META-INF/web-fragment.xml and jar:file:/C:/path/to/project/webroot/WEB-INF/lib/primefaces-2.1.jar!/META-INF/web-fragment.xml

It worked fine with plugin version 7.2.0. I was upgrading because I needed el-api 2.2. Any ideas? Thanks

Marcel

Answer 1

I think we should fight the cause instead of hiding the problem. I.e. avoid duplicate fragments. In my case fragments with the same name came from different versions of Spring, so to solve the issue I had to manage my project's dependencies properly. Analyze by the error message where are the duplicates and think whether you really need both of them or is it a dependency conflict.

Answer 2

If you tried Stephen Connolly's fix and you are still are having issues, you may just need to modify a your web.xml slightly to get "allowDuplicateFragmentNames" to work.

In your WEB-INF/web.xml, look for the tag (should be at the top), and modify atributes to match these values:

<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/j2ee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
metadata-complete="true"
..
>