[jira] [Commented] (OLINGO-312) Reading resource via Classloader

["Chandan V.A (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/OLINGO-312?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14016489#comment-14016489 ] 

Chandan V.A commented on OLINGO-312:
------------------------------------

Hi,
Instead of JPA processor internally reading the mapping XML based on different runtime environments (including OSGI) what if the applications provide the mapping XML as Input stream to JPA Processor through callback mechanism.

For Example JPAEdmExtension Interface will have an additional method say "loadMappingModel". Applications shall implement this method to read the Mapping XML and provide the XML as input stream. JPA processor while constructing the EDM model will make a call to this method to see if there is any input stream available else would fallback to loading it via Class Loader (current implementation) .

So in your use case you might have to implement this callback method.

I hope this solves your issue which very specific to Websphere platform and also would solve issues arising from other platforms (say OSGI).

Thanks
Kind Regards
Chandan

> Reading resource via Classloader
> --------------------------------
>
>                 Key: OLINGO-312
>                 URL: https://issues.apache.org/jira/browse/OLINGO-312
>             Project: Olingo
>          Issue Type: Bug
>          Components: odata2-jpa
>    Affects Versions: V2 1.2.0
>            Reporter: Giacomo Pati
>            Assignee: Chandan V.A
>
> While many servlet-containers tested by me work fine with construct below, WebSphere 8 doesn't like it and returns null for the resources path requested (it's actually outside of Classloader managed filesystem area, which I would consider being bad practice):
> {code}
> InputStream is = JPAEdmMappingModelService.class.getClassLoader().getResourceAsStream("../../" + mappingModelName);
> {code}
> As the class in question (JPAEdmMappingModelService) doesn't have access to the servlet context to properly read a file from the web space area I'd suggest (also for backwards compatibility reasons) to add this to the code as shown in the following patch:
> {code}
> @@ -195,6 +195,9 @@ public class JPAEdmMappingModelService implements JPAEdmMappingModelAccess {
>    protected InputStream loadMappingModelInputStream() {
>      InputStream is = JPAEdmMappingModelService.class.getClassLoader().getResourceAsStream("../../" + mappingModelName);
> +      if(is == null) {
> +          is = JPAEdmMappingModelService.class.getClassLoader().getResourceAsStream(mappingModelName);
> +      }
>      return is;
> {code}
> which would alternatively allow to put the mapping file into the WEB-INF/classes folder.



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