java - Refactoring to test -

i have piece of code equivalent following.

  public class concretethread extends otherthread {   private daofirst firstdao;   private daosecond seconddao;   private transformservice transformservice;   private networkservice networkservice;    public concretethread(daofirst first, daosecond second, transformservice service1,         networkservice service2) {     firstdao = first;     seconddao = second;     transformservice = service1;     networkservice = service2;   }    public future go() {     results r1 = firstdao.getresults();     mycallable c1 = new mycallable(r1);     return super.getthreadpool().submit(c1);   }    private class mycallable implements callable {        private results result;      private long count;     private mycallable(results r) {       this.result = r;       this.count = new long(0);     }      public long call() {       singleton transactions = singleton.getinstance();       try {         transactions.begin();         while(result != null) {           transformed t = transformservice.transform(r1);           networkservice.sendsomewhere(t);           count = count += result.size();           seconddao.persist(result);           result = firstdao.getnext(result);         }       }       catch (exception e) {         e.printstacktrace();       }       {          transactions.end();        }     }   }   

neither of these classes (the inner or outer) have unit tests, , turns out inner class, mycallable, has bug in it. in simplified version of code i've given above, bug isn't present.

so, lets assume decide fix bug, , implement unit tests mycallable. question this; how go writing unit tests mycallable inner class?

my own solution first refactor mycallable , concretethread. mycallable made public class in own file, , concretethread passes in daos, services , singleton constructor arguments mycallable, rather relying on inner-class' access it's private variables.

i used easymock heavily in unit tests mock dependencies , verify being called in manner expected.

a consequence of code mycallable larger was. no longer has access private variables in concretethread, concretethread must pass them in arguments in constructor, , mycallable sets them private variables.

do think wrong approach? perhaps in performing sort of refactoring have broken encapsulation , added unnecessary boilerplate code base? have used reflection in tests instead?

a consequence of code mycallable larger was. no longer has access private variables in concretethread, concretethread must pass them in arguments in constructor, , mycallable sets them private variables.

that's consequence, mycallable no longer dependent on changes in concretethread.

i think question , answer quite subjective, think followed solid principle in refactoring (which thing).

and if can, make mycallable package protected, not public :)