高并发编程-异步-JDK8-CompletableFuture(三)

七.任务交互

　　任务交互就是指两个线程获取任务速度的比较，按照规则进行下一步的处理。

　1.applyToEither

　　两个线程任务进行比较,先获得执行结果的，执行下一步的操作,有返回值

public <U> CompletionStage<U> applyToEither(CompletionStage<? extends T> other,Function<? super T, U> fn);
public <U> CompletionStage<U> applyToEitherAsync(CompletionStage<? extends T> other,Function<? super T, U> fn);
public <U> CompletionStage<U> applyToEitherAsync(CompletionStage<? extends T> other,Function<? super T, U> fn,Executor executor);

 代码实例

public static void main(String[] args) throws InterruptedException {
    applyToEitherDemo();
    countDownLatch.await();


}
@SneakyThrows
public static void  applyToEitherDemo(){
    CompletableFuture<Integer> futrue1 = CompletableFuture.supplyAsync(new Supplier<Integer>() {
        @SneakyThrows
        @Override
        public Integer get() {
            int number = new Random().nextInt(10);
            System.out.println(Thread.currentThread().getName() + "第一个任务线程获得的随机数：" + number);
            Thread.sleep(5000);
            return number;
        }
    });


    CompletableFuture<Integer> futrue2 = CompletableFuture.supplyAsync(new Supplier<Integer>() {
        @SneakyThrows
        @Override
        public Integer get() {
            int number = new Random().nextInt(10);
            System.out.println(Thread.currentThread().getName() + "第二个任务线程获得的随机数：" + number);
            Thread.sleep(2000);
            return number;
        }
    });

    CompletableFuture<Integer> futrue3 = futrue1.applyToEither(futrue2, new Function<Integer, Integer>() {


        @Override
        public Integer apply(Integer num) {
            System.out.println("查询最快的数字为" + num);

            return num * 2;
        }
    });

    System.out.println(futrue3.get());

}

 　　2.acceptEither

　　　　两个线程任务相比较，先获得执行结果的，就对该结果进行下一步的消费操作,无返回值

public CompletionStage<Void> acceptEither(CompletionStage<? extends T> other,Consumer<? super T> action);
public CompletionStage<Void> acceptEitherAsync(CompletionStage<? extends T> other,Consumer<? super T> action);
public CompletionStage<Void> acceptEitherAsync(CompletionStage<? extends T> other,Consumer<? super T> action,Executor executor);

　　使用实例

 public static void main(String[] args) throws InterruptedException {
        acceptEitherDemo();
        countDownLatch.await();


    }

    @SneakyThrows
    public static void  acceptEitherDemo(){

        CompletableFuture<Integer> futrue1 = CompletableFuture.supplyAsync(new Supplier<Integer>() {
            @SneakyThrows
            @Override
            public Integer get() {
                int sum = new Random().nextInt(20);
                Thread.sleep(5000);
                System.out.println(Thread.currentThread().getName() + "第一阶段" + sum);
                return sum;
            }
        });

        CompletableFuture<Integer> futrue2 = CompletableFuture.supplyAsync(new Supplier<Integer>() {


            @SneakyThrows
            @Override
            public Integer get() {
                int sum = new Random().nextInt(20);
                Thread.sleep(7000);
                System.out.println(Thread.currentThread().getName() + "第二阶段" + sum);
                return sum;
            }
        });
        CompletableFuture<Void> result = futrue1.acceptEither(futrue2, new Consumer<Integer>() {
            @Override
            public void accept(Integer sum) {
                System.out.println("先结束的数值为" + sum);

            }
        });
        System.out.println(result.get());
    }

　　3.runAfterEither

　　　　两个线程相比较，有任何一个线程执行完毕就执行下一步的操作，不考虑线程的返回结果。

public CompletionStage<Void> runAfterEither(CompletionStage<?> other,Runnable action);

public CompletionStage<Void> runAfterEitherAsync(CompletionStage<?> other,Runnable action);

public CompletionStage<Void> runAfterEitherAsync(CompletionStage<?> other,Ru nnable action,Executor executor);

　　使用实例

public static void runAfterEitherDemo(){
        CompletableFuture<Integer> futrue1 = CompletableFuture.supplyAsync(new Supplier<Integer>() {


            @SneakyThrows
            @Override
            public Integer get() {
                int sum = new Random().nextInt(10);
                Thread.sleep(1000);
                System.out.println(Thread.currentThread().getName() + "获取的随机数为" + sum);


                return sum;
            }

        });


        CompletableFuture<Integer> futrue2 = CompletableFuture.supplyAsync(new Supplier<Integer>() {


            @SneakyThrows
            @Override
            public Integer get() {
                int sum = new Random().nextInt(10);
                Thread.sleep(3000);
                System.out.println(Thread.currentThread().getName() + "获取的随机数为" + sum);


                return sum;
            }

        });
        futrue2.runAfterEither(futrue1, new Runnable() {
            @Override
            public void run() {
                System.out.println("已经有线程执行完毕");

　　　　　　　　　　countDownLatch.countDown();
}

} }); }

　　4.anyOf

　　anyOf 方法的参数是多个给定的 CompletableFuture，当其中的任何一个完成时，方法返回这个 CompletableFuture。

public static CompletableFuture<Object> anyOf(CompletableFuture<?>... cfs)

　　使用实例

　　

    @SneakyThrows
    public static void anyOfDemo(){
        ExecutorService executorService = Executors.newFixedThreadPool(3);
        CompletableFuture<Integer> futrue1 = CompletableFuture.supplyAsync(new Supplier<Integer>() {


            @SneakyThrows
            @Override
            public Integer get() {
                int sum = new Random().nextInt(30);
                Thread.sleep(3000);
                System.out.println(Thread.currentThread().getName() + "开始执行：" + sum);
                return sum;
            }
        },executorService);
        CompletableFuture<Integer> futrue2 = CompletableFuture.supplyAsync(new Supplier<Integer>() {


            @SneakyThrows
            @Override
            public Integer get() {
                int sum = new Random().nextInt(30);
                Thread.sleep(5000);
                System.out.println(Thread.currentThread().getName() + "开始执行：" + sum);
                return sum;
            }
        },executorService);

        CompletableFuture<Integer> futrue3 = CompletableFuture.supplyAsync(new Supplier<Integer>() {

            @SneakyThrows
            @Override
            public Integer get() {
                int sum = new Random().nextInt(30);
                Thread.sleep(2000);
                System.out.println(Thread.currentThread().getName() + "开始执行：" + sum);
                return sum;
            }
        },executorService);

        CompletableFuture<Object> result = CompletableFuture.anyOf(futrue1, futrue2, futrue3);

        System.out.println(result.get());

    }

　　5.allOf

　　　　多个 CompletableFuture 的同时返回　　

public static CompletableFuture<Void> allOf(CompletableFuture<?>... cfs)

　

 

 @SneakyThrows
    public static void allOfDemo(){
        ExecutorService executorService = Executors.newFixedThreadPool(3);
        CompletableFuture<Integer> futrue1 = CompletableFuture.supplyAsync(new Supplier<Integer>() {


            @SneakyThrows
            @Override
            public Integer get() {
                int sum = new Random().nextInt(30);
                Thread.sleep(3000);
                System.out.println(Thread.currentThread().getName() + "开始执行：" + sum);
                return sum;
            }
        },executorService);


        CompletableFuture<Integer> futrue2 = CompletableFuture.supplyAsync(new Supplier<Integer>() {


            @SneakyThrows
            @Override
            public Integer get() {
                int sum = new Random().nextInt(30);
                Thread.sleep(5000);
                System.out.println(Thread.currentThread().getName() + "开始执行：" + sum);
                return sum;
            }
        },executorService);



        CompletableFuture<Integer> futrue3 = CompletableFuture.supplyAsync(new Supplier<Integer>() {


            @SneakyThrows
            @Override
            public Integer get() {
                int sum = new Random().nextInt(30);
                Thread.sleep(2000);
                System.out.println(Thread.currentThread().getName() + "开始执行：" + sum);
                return sum;
            }
        },executorService);

        CompletableFuture<Object> result = CompletableFuture.anyOf(futrue1, futrue2, futrue3);

        System.out.println(result.get());

    }

 

CompletableFuture 应用实例
　　

 

 　　这是一个烧水泡茶的程序，这里又两个线程，一个线程是T1，执行的操作是洗水壶、烧开水、等待拿茶叶之后泡茶。T2线程执行洗茶壶、洗茶杯、拿茶叶。T1在执行工序时，要等待T2执行完毕。

　　

 @SneakyThrows
    public static void TeaDemo(){
        ExecutorService executorService = Executors.newFixedThreadPool(3);
        CompletableFuture<Void> f1 = CompletableFuture.runAsync(() -> {
            System.out.println(Thread.currentThread().getName() + "洗水壶");
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }


            System.out.println(Thread.currentThread().getName() + "洗水杯");
            try {
                Thread.sleep(2000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

        }, executorService);
        CompletableFuture<String> f2 = CompletableFuture.supplyAsync(new Supplier<String>() {


            @Override
            public String get() {
                System.out.println(Thread.currentThread().getName() + "洗茶壶");
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }


                System.out.println(Thread.currentThread().getName() + "洗茶杯");
                try {
                    Thread.sleep(2000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }


                System.out.println(Thread.currentThread().getName() + "拿茶叶");
                try {
                    Thread.sleep(3000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }

                return "龙井";
            }
        });
        CompletableFuture<String> f3 = f2.thenCombine(f1, (name, _a) -> {
            System.out.println("拿到了茶叶" + name);
            System.out.println("开始泡茶");


            return "龙井茶泡好了";
        });
        System.out.println(f3.get());
        countDownLatch.countDown();

    }