Resource attribute of DataWeave in Mule is not accepting flow variable - mule

Question

My dataweave code configuration xml is as below :
<dw:transform-message doc:name="Transform Message">
<dw:set-payload resource="#[flowVars['sample']]" />
</dw:transform-message>
where sample is a flow variable that contains the file path of the .dwl file that has the actual transformation logic.
<set-variable doc:name="Variable" value="file:D:/Transformer/sample.dwl" variableName="sample"/>
The error that i see when deploying the application is as follows:
org.mule.module.launcher.DeploymentInitException: FileNotFoundException: class path resource [#[flowVars['sample']]] cannot be opened because it does not exist
at org.mule.module.launcher.application.DefaultMuleApplication.init(DefaultMuleApplication.java:197) ~[mule-module-launcher-3.7.3.jar:3.7.3]
at org.mule.module.launcher.artifact.ArtifactWrapper$2.execute(ArtifactWrapper.java:62) ~[mule-module-launcher-3.7.3.jar:3.7.3]
at org.mule.module.launcher.artifact.ArtifactWrapper.executeWithinArtifactClassLoader(ArtifactWrapper.java:129) ~[mule-module-launcher-3.7.3.jar:3.7.3]
at org.mule.module.launcher.artifact.ArtifactWrapper.init(ArtifactWrapper.java:57) ~[mule-module-launcher-3.7.3.jar:3.7.3]
at org.mule.module.launcher.DefaultArtifactDeployer.deploy(DefaultArtifactDeployer.java:25) ~[mule-module-launcher-3.7.3.jar:3.7.3]
at org.mule.module.launcher.DefaultArchiveDeployer.guardedDeploy(DefaultArchiveDeployer.java:324) ~[mule-module-launcher-3.7.3.jar:3.7.3]
at org.mule.module.launcher.DefaultArchiveDeployer.deployArtifact(DefaultArchiveDeployer.java:345) ~[mule-module-launcher-3.7.3.jar:3.7.3]
at org.mule.module.launcher.DefaultArchiveDeployer.deployPackagedArtifact(DefaultArchiveDeployer.java:163) ~[mule-module-launcher-3.7.3.jar:3.7.3]
at org.mule.module.launcher.DefaultArchiveDeployer.deployPackagedArtifact(DefaultArchiveDeployer.java:268) ~[mule-module-launcher-3.7.3.jar:3.7.3]
at org.mule.module.launcher.DefaultArchiveDeployer.deployPackagedArtifact(DefaultArchiveDeployer.java:83) ~[mule-module-launcher-3.7.3.jar:3.7.3]
at org.mule.module.launcher.DeploymentDirectoryWatcher.deployPackedApps(DeploymentDirectoryWatcher.java:275) ~[mule-module-launcher-3.7.3.jar:3.7.3]
at org.mule.module.launcher.DeploymentDirectoryWatcher.start(DeploymentDirectoryWatcher.java:150) ~[mule-module-launcher-3.7.3.jar:3.7.3]
at org.mule.module.launcher.MuleDeploymentService.start(MuleDeploymentService.java:104) ~[mule-module-launcher-3.7.3.jar:3.7.3]
at org.mule.module.launcher.MuleContainer.start(MuleContainer.java:170) ~[mule-module-launcher-3.7.3.jar:3.7.3]
at org.mule.tooling.server.application.ApplicationDeployer.main(ApplicationDeployer.java:15) ~[tooling-support-3.7.3.jar:?]
Caused by: org.mule.api.config.ConfigurationException: IOException parsing XML document from URL [file:/C:/Users/Satyakeerthika_Ch/AnypointStudio/workspaceLatest/.mule/apps/sample/sample.xml]; nested exception is java.io.FileNotFoundException: class path resource [#[flowVars['sample']]] cannot be opened because it does not exist (org.mule.api.lifecycle.InitialisationException) (org.mule.api.config.ConfigurationException)
at org.mule.config.builders.AbstractConfigurationBuilder.configure(AbstractConfigurationBuilder.java:49) ~[mule-core-3.7.3.jar:3.7.3]
at org.mule.config.builders.AbstractResourceConfigurationBuilder.configure(AbstractResourceConfigurationBuilder.java:69) ~[mule-core-3.7.3.jar:3.7.3]
at org.mule.context.DefaultMuleContextFactory$1.configure(DefaultMuleContextFactory.java:89) ~[mule-core-3.7.3.jar:3.7.3]
at org.mule.context.DefaultMuleContextFactory.doCreateMuleContext(DefaultMuleContextFactory.java:222) ~[mule-core-3.7.3.jar:3.7.3]
at org.mule.context.DefaultMuleContextFactory.createMuleContext(DefaultMuleContextFactory.java:81) ~[mule-core-3.7.3.jar:3.7.3]
at org.mule.module.launcher.application.DefaultMuleApplication.init(DefaultMuleApplication.java:188) ~[mule-module-launcher-3.7.3.jar:3.7.3]
... 14 more
Can someone help me how to read the variable in the resource?

Answer 1

You can't do it that way, but you can use the MEL function to evaluate dataweave scripts inside a set-payload.
#[dw(<dw-script-string>)]
#[dw(<dw-script-string>, <out-content-type>)]
If you don't specify a content-type the default is java.
So, it would end up as:
<set-payload value="#[dw(<dw-script-string>)]" doc:name="Set Payload"/>
Link to docs

Answer 2

I also experience the same issue in my anypoint studio with Mule 3.9.0
I had to correct the java library in my anypoint studio using below guide.
right click on the project
select properties from the context menu
on the project propearties page select java build path
in java build path click on libraries
select Add Library -> click on JRE System Library
select alternate JRE and browse to the JDK you would like to add to the project
this should resolve your issue