Java中Runnable与Callable接口的区别详解

public static void main(String[] args) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                System.out.println(Thread.currentThread().getName() + "我是一个无返回结果的任务线程");
            }
        },"线程一:").start(); //start()开启任务
    }

public class PrimitiveCallable implements Callable, Runnable {
    
    public static void main(String[] args) {
        //实现
        new Thread(new PrimitiveCallable(), "线程二:").start();
    }
    @Override
    public void run() {//Runnable实现
        try {
            Object call = this.call();
            System.out.println(call);
        } catch (Exception exception) {
            exception.printStackTrace();
        }
    }
    @Override
    public Object call() throws Exception { //Callable 实现
        return "异步任务返回的结果!!!";
    }
}

public class FutureTask<V> implements RunnableFuture<V> { //RunnableFuture 实现了以上2个接口
    ........省略.........
	public void run() { //重写run实现
        if (state != NEW ||
            !UNSAFE.compareAndSwapObject(this, runnerOffset,
                                         null, Thread.currentThread()))
            return;
        try {
            Callable<V> c = callable; //构建对象是传入的参数
            if (c != null && state == NEW) {
                V result;
                boolean ran;
                try {
                    result = c.call(); //调用任务并返回结果
                    ran = true;
                } catch (Throwable ex) {
                    result = null;
                    ran = false;
                    setException(ex); //设置异常时的结果
                }
                if (ran)
                    set(result); //设置结果
            }
        } 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)