Using Java Stream API in already multi-threaded environment -

my application has own thread pool(mythreadpool) , assigning 1 of threads(producer) read file via java stream api. in runtime stream lost somewhere , never reaches print method. when run stream in single threaded environment works. happen because java stream api uses own thread pool underneath or conceptually wrong?

public class processor {    public void process() {     executorservice mythreadpool = executors.newfixedthreadpool(3);     mythreadpool.execute(new producer());   }    private class producer implements runnable{     @override     public void run() {         try (stream<string> lines = files.lines(paths.get("path"))) {             system.out.println(lines.count());         } catch (ioexception e) {             e.printstacktrace();         }     }  } } 

i don't know have happen. can give advice (maybe program exited , producer not terminated). copy code , see wrong of code.

public class processor {      public void process() {         executorservice mythreadpool = executors.newfixedthreadpool(3);         try {             mythreadpool.execute(new producer());             thread.currentthread().join();         } catch (exception ex) {             ex.printstacktrace();         }     }      private class producer implements runnable {         @override         public void run() {             try (stream<string> lines = files.lines(paths.get("path"))) {                 system.out.println(lines.count());             } catch (ioexception e) {                 e.printstacktrace();             }         }     } } 

or

public class processor {      public void process() {         executorservice mythreadpool = executors.newfixedthreadpool(3);         try {             mythreadpool.submit(() -> {                 new producer().run();                 return null;             }).get();         } catch (exception ex) {             ex.printstacktrace();         }     }      private class producer implements runnable {         @override         public void run() {             try (stream<string> lines = files.lines(paths.get("path"))) {                 system.out.println(lines.count());             } catch (ioexception e) {                 e.printstacktrace();             }         }     } }