multithreading - Java - Run a method on Main thread, called from worker thread -

how can call , run method on main thread, called worker thread?

main thread code, (foo() function accessible main thread):

thread newthread = new thread(mythread, mythread.getthreadname()); newthread.start(); 

worker thread code (newthread):

@override public void run(){ // need call here foo() function - has run on main thread } 

thanks!

the words "call method in thread" have no meaning in java.

you need understand thread , thread 2 different things: thread path of execution through code. thread java object can used start new thread , manage life cycle.

a new thread begins when other thread calls t.start() t refers thread object. thread begins executing t.run() method, , wanders , out of function calls until reaches end of t.run(), @ point dies. meanwhile, other threads following own paths through code.

at lowest level, only way 1 thread interact updating fields of shared objects , classes.

thread can tell thread b execute function or sending message (i.e., updating field in object), thread can never make thread b something. thread b can code executing says do. if code says, @ field f, , if value greater zero, call function foobar(), thread b do. or if code tells pop runnable off of queue , call runnable's run() method, thread do.

but no thread can change code other thread running once thread starts running it. can change fields influence code next.