Adding ExecutorService files

Java/ExecutorService/ExecutorServiceCallableExample.java

@@ -0,0 +1,48 @@
+import java.util.concurrent.*;
+
+class CallableTask implements Callable<Integer>{
+    private int id;
+
+    CallableTask(int id){
+        this.id = id;
+    }
+    @Override
+    public Integer call() {
+        try {
+            TimeUnit.MILLISECONDS.sleep(5000);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+        return id;
+    }
+}
+
+public class ExecutorServiceCallableExample {
+
+    static void printFutureData(Future future){
+        System.out.println("isDone : "+future.isDone());
+
+        try {
+            System.out.println("get : "+future.get());
+        } catch (InterruptedException | ExecutionException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public static void main(String[] args) {
+        ExecutorService service = Executors.newFixedThreadPool(2);
+
+        Future future = service.submit(new CallableTask(1));
+        service.shutdown();
+
+        while(!future.isDone()){
+            try {
+                System.out.println("Waiting for the Future to complete ...");
+                Thread.sleep(1000);
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        }
+        printFutureData(future);
+    }
+}