Java Futures usage #java #future #concurrency #multithreading #communication

FuturesConcurrency.java

/* This program is free software. It comes without any warranty, to
* the extent permitted by applicable law. You can redistribute it
* and/or modify it under the terms of the Do What The Fuck You Want
* To Public License, Version 2, as published by Sam Hocevar. See
* http://www.wtfpl.net/ for more details. 
*/
    /**
     *  Executes Multiple futures 
     * 
     */
    public void futureRequests(){
        
        List<Future<Object>> rawList = new ArrayList<Future<Object>>();

        ExecutorService executor = Executors.newCachedThreadPool();
        List<Object> results = new ArrayList<Object>();

        //this.parameters is a List with the parameters for the executors
        for(Object o : this.parameters){
            rawList.add(executor.submit(new CustomFuture(o)));
        }

        for(Future<Object> futu : rawList){
            try {
                results.add(futu.get());

            } catch (InterruptedException ex) {
                Logger.getLogger(SimulationBean.class.getName()).log(Level.SEVERE, null, ex);
            } catch (ExecutionException ex) {
                Logger.getLogger(SimulationBean.class.getName()).log(Level.SEVERE, null, ex);
            }
        }


    }
    private class CustomFuture implements Callable<Object>{

        Object parameter;

        public CustomFuture(Object parameter) {
            this.parameter = parameter;
        }


        @Override
        public Serializable call() throws Exception {
            return someLongMethodCall(this.object);
        }

    }