Java, create threads Three ways: to achieve Callable Interface

java.util.concurrent.Callable Import; 
Import java.util.concurrent.ExecutionException; 
Import java.util.concurrent.FutureTask; 

/ ** 
* Create a thread Three ways: implement Callable interface. --- JDK 5.0 added 
* 
* 
* How to understand the way to achieve Callable interface to create multi-threaded multi-threaded Runnable interface to create powerful than achieved? 
* 1. call () can return a value. 
* 2. call () can throw an exception, being outside of the capture operation, access to information abnormalities 
* 3. Callable supports generic 
* 
* / 
// 1. Create an implementation class that implements the Callable 
class NumThread the implements Callable { 
    / . / 2 to achieve a method call, this operation is declared to be executed thread () in the call 
    @Override 
    public Object call () throws Exception { 
        int SUM = 0; 
        for (int I =. 1; I <= 100; I ++) { 
            if (i% 2 == 0) {
                System.out.println (I); 
                SUM = I +; 
            } 
        } 
        return SUM; 
    } 
} 


public class ThreadNew { 
    public static void main (String [] args) { 
        .. 3 // Create Callable interface class object 
        NumThread numThread = numThread new new (); 
        // this. 4 Callable object class interface as FutureTask passed to the constructor, creates FutureTask object. 
        FutureTask FutureTask = new new FutureTask (numThread); 
        .. 5 // FutureTask the object passed as an argument to the Thread class constructor Create Thread object and calls Start () 
        new new Thread (FutureTask) .start (); 

        the try { 
            . Callable acquired. 6 // the return value of the call 
            // get () returns the value is the FutureTask Callable implementation class constructor argument rewritten to call () return value.
            Object sum = futureTask.get();
            System.out.println("总和为：" + sum);
        } catch (InterruptedException e) {
            e.printStackTrace();
        } catch (ExecutionException e) {
            e.printStackTrace();
        }
    }

}