Hmm.. I'm not sure if I understood what you're trying to do but let's try this: If you're embedding the PlatterCode class in the TreatmentPlatter class, I suppose you want to query TreatmentPlatter instances that have a certain platter code, right? In this scenario, you probably have an attribute that maps the platter code in your PlatterCode class, let's call it platterCode. Now, you have to annotate this platterCode attribute with @Field, not the oid attribute. So you can search like this:
Code:
String[] fields = new String[]{"oid","platterCode","code","description","location","dxLocation", "platterCode.platterCode"};
MultiFieldQueryParser parser = new MultiFieldQueryParser(fields, new StandardAnalyzer());
String searchString = "platterCode.platterCode: 3"; // here you want to find platter codes with code '3'
org.apache.lucene.search.Query query = parser.parse(searchString);
// wrap Lucene query in a org.hibernate.Query
org.hibernate.Query hibQuery = fullTextSession.createFullTextQuery(query, TreatmentPlatter.class);
List result = hibQuery.list();
Is this what you wanted to do?