jms - serial execution in Java-ee -

i have incoming concurrent requests should processed in serial. have attempted achieve converting requests messages , post jms queue. use mdb process queue.

using vendor specific config, understand can limit mdb 1 instance, recommended , portable way solve problem?

edit: forgot mention don't need features of jms (reliability etc).

assume have job this.

class logjob implements runnable{     private final string name;     public logjob(string name){         this.name = name;     }     @override     public void run() {         system.out.println(" starting ."+name);         try {             thread.sleep(1000);         } catch (interruptedexception e) {             // todo auto-generated catch block             e.printstacktrace();         }         system.out.println(" end ."+name);     } } 

it display starting , ending job. placed sleep demo

create list of jobs

        arraylist<logjob> jobs = new arraylist<logjob>();         ( int i=0;i<10;i++){             logjob job = new logjob("job"+i);             jobs.add(job);         } 

let see how process in serial

   executorservice singlethread = executors.newsinglethreadexecutor();         (iterator<logjob> iterator = jobs.iterator(); iterator.hasnext();) {             singlethread.execute(iterator.next());         }         singlethread.shutdown(); 

this provide output.

starting .job0  end .job0  starting .job1  end .job1  starting .job2  end .job2  starting .job3  end .job3  starting .job4  end .job4  starting .job5  end .job5  starting .job6  end .job6  starting .job7  end .job7  starting .job8  end .job8  starting .job9  end .job9 

---

update

based on conversation in comment, came know have use in java-ee environment. said have use managedexecutorservice . how ever dont need use singleton ejb , concurrentlinkedqueue.

you can implement jobs callable , can block further processing using future.get()

string name = managedservice.submit(iterator.next()).get(); 

from api

    if block waiting task,  can use constructions of form result = exec.submit(acallable).get();