Details
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Bug
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Resolution: Done
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Major
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None
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None
Description
If the same class is container in 2 modules and 1 module depends on the other. In EAP 7, the class in the resource-root will take precedence over the class coming from the dependency. This is a change from EAP 6 where the class from the dependency would take precedence over the one in the resource-root.
Attaching test-overlay.zip which can be unzipped onto EAP 6 or EAP 7
unzip -d jboss-eap-7/ test-overlay.zip
Start the server and it will log a message indicating which took priority.
EAP 7:
com.jboss.examples.servlet.Servlet - Test: Resource Root loaded from: jar:file:/tmp/jboss-eap-7.0/modules/test/main/resource-root.jar!/
EAP 6:
com.jboss.examples.servlet.Servlet - Test: Dependency loaded from: jar:file:/tmp/jboss-eap-6.4/modules/test/dependencies/main/dependency.jar!/
<module xmlns="urn:jboss:module:1.1" name="test"> <resources> <resource-root path="resource-root.jar"/> </resources> <dependencies> <module name="test.dependencies" export="true"/> </dependencies> </module>
<module xmlns="urn:jboss:module:1.1" name="test.dependencies"> <resources> <resource-root path="dependency.jar"/> </resources> <dependencies> <module name="javax.api"/> </dependencies> </module>
Side note when classes are duplicate in modules, it is important to ensure that there is only 1 class visible to a deployment or module otherwise ClassCastException, LinkageError and other Classloading errors can occur.
A module can prevent exporting of classes using exports (exclude/include) as shown below:
<module xmlns="urn:jboss:module:1.1" name="org.apache.santuario.xmlsec"> <exports> <exclude path="javax/**"/> </exports> ... </module>
A module can also include/exclude classes from a module it depends on such as:
<module xmlns="urn:jboss:module:1.1" name="org.picketlink.federation"> ... <module name="org.apache.santuario.xmlsec"> <imports> <exclude path="javax/*"/> </imports> </module> ... <module name="org.picketlink.config"> <imports> <exclude-set> <path name="org.picketlink.config.idm"/> </exclude-set> </imports> </module>
