import java class into matlab fails because class not found

hi everyone,

I'm importing java classes into MATLAB from the command line. First I do

>> javaaddpath('hadoop-1.1.2/hadoop-core-1.2.0.jar');

Inside my jar file I can see the class list

org/apache/hadoop/security/KerberosInfo.class

org/apache/hadoop/security/KerberosName$BadFormatString.class

org/apache/hadoop/security/KerberosName$NoMatchingRule.class

org/apache/hadoop/security/KerberosName$Rule.class

org/apache/hadoop/security/KerberosName.class

and so on. However importing the KerberosName class fails:

>> import org.apache.hadoop.security.KerberosName

Error using import Import argument 'org.apache.hadoop.security.KerberosName' cannot be found or cannot be imported.

I don't see this error with any other class in the jar. Also, the class imports ok outside MATLAB in a standalone java job so I think the jar file is sound.

Does anybody see any reason why this class:

https://hadoop.apache.org/docs/r1.1.2/api/org/apache/hadoop/security/KerberosName.html

would not import into MATLAB?

best

Ellie