创建线程的4种方法

线程创建方法

1、继承Thread，重写run方法

	    private static void one() {

            class T extends Thread{
                @Override
                public void run() {
                    log.debug("one is running...");
                }
            }

            T t = new T();
            t.start();
        }

简写

    private static void one() {

        Thread t = new Thread(){
            @Override
            public void run() {
                log.debug("one is running...");
            }
        };

        t.start();
    }

结果如图

2、Runnable配合Thread

Thread代表线程

Runnable代表可运行的任务（要执行的代码）

Runnable实现run方法，创建的对象作为Thread的构造参数

    private static void two() {
        Runnable runnable = new Runnable() {
            @Override
            public void run() {
                log.debug("two is running...");
            }
        };

        Thread t = new Thread(runnable);
        t.start();

//        //简写
//        Thread t = new Thread() {
//            @Override
//            public void run() {
//                log.debug("two is running...");
//            }
//        };
//        t.start();

//        //lambda表达式
//        Thread t = new Thread(() -> {
//            log.debug("two is running...");
//        });
//        t.start();
    }

3、FutureTask配合Thread

    private static void three() {
        //FutureTask间接继承了Runnable
        FutureTask<Integer> task = new FutureTask<Integer>(() -> {
            log.debug("three is running...");
            return 1;
        });

        Thread t3 = new Thread(task);
        t3.start();
    }

FutureTask可以接受Callable类型的参数，同时间接继承了Runnable，所以FutureTask可以作为Thread的构造参数创建线程

结果如图

4、使用ThreadPoolExecutor执行任务

    private static void four() {
        ThreadPoolExecutor t1 = new ThreadPoolExecutor(
                //核心线程数
                2,
                //最大线程数
                3,
                //救急线程存活时间
                1,
                //救急线程存活时间单位
                TimeUnit.SECONDS,
                //任务队列
                new ArrayBlockingQueue<Runnable>(5),
                //线程工厂，可以给线程起一个好名字
                r -> new Thread(r, "t1"),
                //拒绝策略
                new ThreadPoolExecutor.AbortPolicy()
        );

        t1.execute(() -> {
            log.debug("four is running...");
        });
    }