java - How to run different methods parallely -

i have 1 java method contains 5 different internal methods. performance improvement, want call these methods parallely.

e.g. run method1, method2, ... method5 parallel using thread.

private void getinformation() throws sqlexception,             classnotfoundexception, namingexception {     method1();     method2();     method3();     method4();     method5(); } 

but these 5 methods have different business logic.

do this:

1. for each method, create callable object wraps method.
2. create executor (a fixed thread pool executor should fine).
3. put callables in list , invoke them executor
4. iterate on each future returned executor, wait thread complete, , results. here's simple example:

public void testthread() {     //create callable each method    callable<void> callable1 = new callable<void>()    {       @override       public void call() throws exception       {          method1();          return null;       }    };     callable<void> callable2 = new callable<void>()    {       @override       public void call() throws exception       {          method2();          return null;       }    };     callable<void> callable3 = new callable<void>()    {       @override       public void call() throws exception       {          method3();          return null;       }    };     //add list    list<callable<void>> tasklist = new arraylist<callable<void>>();    tasklist.add(callable1);    tasklist.add(callable2);    tasklist.add(callable3);     //create pool executor 3 threads    executorservice executor = executors.newfixedthreadpool(3);     try    {       //start threads       list<future<void>> futurelist = executor.invokeall(tasklist);        for(future<void> voidfuture : futurelist)       {          try          {             //check status of each future.  block until task             //completes or time expires             voidfuture.get(100, timeunit.milliseconds);          }          catch (executionexception e)          {             system.err.println("error executing task " + e.getmessage());          }          catch (timeoutexception e)          {             system.err.println("timed out executing task" + e.getmessage());          }        }      }    catch (interruptedexception ie)    {       //do if care interruption;    }  }  private void method1() {    system.out.println("method1"); }  private void method2() {    system.out.println("method2"); }  private void method3() {    system.out.println("method3"); } 

make sure each method not share state (like common mutable field in same class) or may unexpected results. oracle provides a introduction java executors. also, this book awesome if doing kind of threading in java.