well from error stack its clear that exception is thrown from line 11 of LoginValidationTest so Port class is not in picture yet. also it is shouting about null argument and only possibility from line 46 of LoginValidation is LOGINVALIDATION_WSDL_LOCATION being null.
I assumed you have overridden WSDL location to http://localhost:8082/JaxWsSunTopDown/LoginServicePort?wsdl is the ?wsdl correct here? I think it should be just [b]http://localhost:8082/JaxWsSunTopDown/LoginServicePort. so you need to rerun wsimport
if this does not work then try using jax-ws-catalog.xml with systemId=http://localhost:8082/JaxWsSunTopDown/LoginServicePort and uri=path of your wsdl, something like wsd/LoginServicePort.wsdl.
hope this helps.
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