java - Submit task which implements a subinterface of Callable<T> to an ExecutorService -

how submit task implements subinterface of callable<t> executorservice?

i have subinterface of callable<t> defined as:

public interface ctigwtask<t>     extends callable {      ... } 

it defines static constants adds no methods.

then have following method execservice fixedthreadpool instance.

@override public ctigwtaskresult<integer> postctitask(ctigwtask<ctigwtaskresult<integer>> task) {      future<ctigwtaskresult<integer>> result =             execservice.submit(task);      try {         return result.get();      } catch (interruptedexception | executionexception ex) {         logger.log(level.finest,                 "could not complete ctigwtask", ex);         return new ctigwtaskresult<>(                 ctigwresultconstants.ctigw_server_shuttingdown_error,                 boolean.false,                 "cannot complete task: ctigateway server shutting down.",                 ex);     } } 

unfortunately giving 2 unchecked conversion , 1 unchecked method invocation warnings.

...\ctigwworkerimpl.java:151: warning: [unchecked] unchecked conversion             execservice.submit(task); required: callable<t> found:    ctigwtask<ctigwtaskresult<integer>> t type-variable:   t extends object declared in method <t>submit(callable<t>)  ...\ctigwworkerimpl.java:151: warning: [unchecked] unchecked method invocation: method submit in interface executorservice applied given types             execservice.submit(task); required: callable<t> found: ctigwtask<ctigwtaskresult<integer>> t type-variable:   t extends object declared in method <t>submit(callable<t>)  ...\ctigwworkerimpl.java:151: warning: [unchecked] unchecked conversion             execservice.submit(task); required: future<ctigwtaskresult<integer>> found:    future 

if change submit call to

future<ctigwtaskresult<integer>> result =     execservice.submit( (callable<ctigwtaskresult<integer>>) task); 

then seems work unchecked cast warning.

...\src\com\dafquest\ctigw\cucm\ctigwworkerimpl.java:151: warning: [unchecked] unchecked cast             execservice.submit((callable<ctigwtaskresult<integer>>) task); required: callable<ctigwtaskresult<integer>> found:    ctigwtask<ctigwtaskresult<integer>> 

so i'm missing? shouldn't submit() apply instance of subclass of callable?

you using raw callable type.

change:

public interface ctigwtask<t> extends callable 

to this:

public interface ctigwtask<t> extends callable<t>