Thread创建

1. 线程分类

     a. 无返回值Runnable,

     b. 有返回值Callable

2. 线程创建

    new Thread(Runnable runnable);

    无返回值的线程:

 new Thread(() -> System.out.println("run runnable")).start();

    有返回值的线程

 FutureTask futureTask = new FutureTask<>(() -> {
            return -1;
        });
        new Thread(futureTask).start();
        Integer integer = futureTask.get();

 FutureTask本身是一个Runnable, 包含成员变量outcome用来存放结果，部分源码如下：

 

3. 使用线程池创建

@Test
    public void test04() throws InterruptedException, ExecutionException {
        ExecutorService executor = Executors.newCachedThreadPool();

        //Runnable
        executor.execute(() -> {
            System.out.println("executor runnable");
        });


        //Callable
        List> taskList = Arrays.asList(new Callable[]{new Callable() {
            @Override
            public Integer call() throws Exception {
                return -1;
            }
        }});
        List> futures = executor.invokeAll(taskList);
        for (Future future : futures) {
            System.out.println(future.get());
        }
    }