[jira] [Resolved] (ARIES-2108) Catch 'NoClassDefFoundError' when loading Service-Provider instances

["Jean-Baptiste Onofré (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/ARIES-2108?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Jean-Baptiste Onofré resolved ARIES-2108.
-----------------------------------------
    Resolution: Fixed

> Catch 'NoClassDefFoundError' when loading Service-Provider instances
> --------------------------------------------------------------------
>
>                 Key: ARIES-2108
>                 URL: https://issues.apache.org/jira/browse/ARIES-2108
>             Project: Aries
>          Issue Type: Bug
>          Components: SPI Fly
>    Affects Versions: spifly-1.3.6
>            Reporter: Hannes Wellmann
>            Assignee: Jean-Baptiste Onofré
>            Priority: Major
>             Fix For: spifly-1.3.7
>
>
> Loading ServiceProvider instances which depend on classes absent at runtime (e.g. because they are contained in an optional dependency) throws a {{NoClassDefFoundError}} instead of a {{{}ClassNotFoundException{}}}, which is propagated to the caller of {{ProviderBundleTrackerCustomizer.addingBundle()}} and leads to an empty list of providers. Instead a {{NoClassDefFoundError}} should be handled like a {{{}ClassNotFoundException{}}}.
> The reason for this different exception in this case is that although the service class is found it cannot be defined.
> The javadoc of {{NoClassDefFoundError}} states:
> {code:java}
> Thrown if the Java Virtual Machine or a ClassLoader instance tries to load in the definition of a class
> (as part of a normal method call or as part of creating a new instance using the new expression)
> and no definition of the class could be found.{code}
> The javadoc of {{ClassNotFoundException}} states:
> {code:java}
> Thrown when an application tries to load in a class through its string name using:
> - The forName method in class Class.
> - The findSystemClass method in class ClassLoader .
> - The loadClass method in class ClassLoader.
> but no definition for the class with the specified name could be found.{code}
> One example where this scenario occurs is Logback for SLF4J-2. Besides the {{SLF4JServiceProvider}} service this bundle also provides a {{{}ServletContainerInitializer{}}}, which is only relevant/intended for server/web-app environments where an implementation of the {{jakarta./javax.servlet}} API is provided.
> Therefore the maven dependencies for {{jakarta./javax.servlet}} are in the provided scope and optional and correspondingly the {{jakarta./javax.servlet}} packages are only optionally imported in the MANIFEST.MF.
> [https://github.com/qos-ch/logback/blob/4e069d34d9422a43511ae7d6242a27caa8834e14/logback-classic/pom.xml#L335-L356]



--
This message was sent by Atlassian Jira
(v8.20.10#820010)