Spring Data MongoDB Index not created when no data available -

i using spring data framework mongodb groovy , can't solve problem: want: want spring data create mongodb collection 2 indices. have pojo class

@document(collection='language') class language {     @id     string id      @indexed(unique = true)     string isocode      string description } 

that repository:

public interface languagerepository extends mongorepository<language, string>    list<language> findbyisocode(string isocode); } 

maybe there more annotations, writing code without having sourcecode right here...

i have written spock test checks if possible insert 2 languages same isocode , expects exceptoion. spock test wires application context , works pretty fine except of 1 point: index not created when run test first time.

i wire test, test inserts twi languages same isocode mongodb , test fails because there no index prevents duplicate isocodes. can see in mongoshell well. test fails because there no index violation , no exception. when run same test again application can't start because spring data seems create index on mongodb - fails, because there duplicate entries in database , creation of index fails (of course...). when delete 1 of entries manually via mongoshell , run same test again works fine, because index can created , expected exception.

can tell me if , why mongodb can create indices if there entries in collection? , if way: how handle issue best?

kind regards sebastian

edit spock test:

def 'there must not duplicate languages'() {         setup:         language lang1 = new language(                 isocode: 'de-de',                 description: 'deutsch (deutschland)'         )         language lang2 = new language(                 isocode: 'de-de',                 description: 'deutsch (schweiz)'         )         languagerepository.save(lang1)          when:         languagerepository.save(lang2)          then:         final org.springframework.dao.duplicatekeyexception ex = thrown()          cleanup:         languagerepository.deleteall()      }