Hey
Sandro2020,
Id double check in your validating .xsd if the elements are nillable=true. Do both the <value /> and <providerOrganizationID /> tags have minOccurs=0 in the .xsd? Both minOccurs and maxOccurs defaults are '1' in xml schema so the elements will need to have minOccurs set to '0' for this to be allowed. What you dont want is nillable=true and minOccurs=1 cos this will force the population of empty elements in your xml instance.
As to your question regarding whether you can use Java rather than groovy? Absolutely. Groovy uses the Java runtime, but you can use any java library from the Java api and use any bespoke ones as long as you add the relevant .jar files in and declare what youre using at the start.
I mentioned groovy cos thats what the default scripting language is packaged with ReadyAPI!. You can use JavaScript too, although that's extra effort and i think people are less knowledegeable on the forum relative to groovy experts on this thing.
Cheers
Rich