package concurrency;

import java.io.*;

import java.util.concurrent.*;

import java.util.*;

/**

* RUN:

* javac concurrency/CallableDemo.java && java concurrency.CallableDemo

*

* OUTPUT:

* result of TaskWithResult 0

* result of TaskWithResult 1

* result of TaskWithResult 2

* result of TaskWithResult 3

* result of TaskWithResult 4

* result of TaskWithResult 5

* result of TaskWithResult 6

* result of TaskWithResult 7

* result of TaskWithResult 8

* result of TaskWithResult 9

*/

public class CallableDemo {

public static void main(String[] args) {

ExecutorService exec = Executors.newCachedThreadPool();

ArrayList<Future<String>> results = new ArrayList<Future<String>>();

for (int i = 0; i < 10; i++) {

results.add(exec.submit(new TaskWithResult(i)));

}

for (Future<String> fs : results) {

try {

System.out.println(fs.get());

}

catch (InterruptedException e) {

System.out.println(e);

return;

}

catch (ExecutionException e) {

System.out.println(e);

}

finally {

exec.shutdown();

}

}

}

}

class TaskWithResult implements Callable<String> {

private int id;

public TaskWithResult(int id) {

this.id = id;

}

public String call() {

return "result of TaskWithResult " + id;

}

}