Java中Runnable與Callable介面的區別詳解

public static void main(String[] args) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                System.out.println(Thread.currentThread().getName() + "我是一個無返回結果的任務執行緒");
            }
        },"執行緒一:").start(); //start()開啟任務
    }

public class PrimitiveCallable implements Callable, Runnable {
    
    public static void main(String[] args) {
        //實現
        new Thread(new PrimitiveCallable(), "執行緒二:").start();
    }
    @Override
    public void run() {//Runnable實現
        try {
            Object call = this.call();
            System.out.println(call);
        } catch (Exception exception) {
            exception.printStackTrace();
        }
    }
    @Override
    public Object call() throws Exception { //Callable 實現
        return "非同步任務返回的結果!!!";
    }
}

public class FutureTask<V> implements RunnableFuture<V> { //RunnableFuture 實現了以上2個介面
    ........省略.........
	public void run() { //重寫run實現
        if (state != NEW ||
            !UNSAFE.compareAndSwapObject(this, runnerOffset,
                                         null, Thread.currentThread()))
            return;
        try {
            Callable<V> c = callable; //構建物件是傳入的引數
            if (c != null && state == NEW) {
                V result;
                boolean ran;
                try {
                    result = c.call(); //呼叫任務並返回結果
                    ran = true;
                } catch (Throwable ex) {
                    result = null;
                    ran = false;
                    setException(ex); //設定異常時的結果
                }
                if (ran)
                    set(result); //設定結果
            }
        } finally {
            runner = null;
            int s = state;
            if (s >= INTERRUPTING)
                handlePossibleCancellationInterrupt(s);
        }
    }
     ........省略.........
}

 public Thread()
 public Thread(Runnable target)
 Thread(Runnable target, AccessControlContext acc)
 public Thread(ThreadGroup group, Runnable target)
 public Thread(String name)
 public Thread(ThreadGroup group, String name)
 public Thread(Runnable target, String name)
 public Thread(ThreadGroup group, Runnable target, String name)
 public Thread(ThreadGroup group, Runnable target, String name,
                  long stackSize)