CompletableFuture异步编排

代码一

public class ThreadTest {

	public static ExecutorService executor = Executors.newFixedThreadPool(10);
	
	public static void main(String[] args) throws Exception {
		System.out.println("main---start");
//		CompletableFuture.runAsync(()->{
//			System.out.printf("当前线程  %d \n",Thread.currentThread().getId());
//			int i = 10/2;
//			System.out.printf("运行结果：%d",i);
//		}, executor);
		CompletableFuture<Integer> future = CompletableFuture.supplyAsync(()->{
			System.out.printf("当前线程  %d \n",Thread.currentThread().getId());
			int i = 10/0;
			System.out.printf("运行结果：%d \n",i);
			return i;
		}, executor).whenComplete((result,exception)->{
			//能得到异常信息，没法修改返回数据
			System.out.println("异步任务成功完成了...\n结果是 " + result + "\n异常是：" + exception);
		}).exceptionally(throwable -> {
			//可以感知异常，同时返回默认值
			return 777;
		});
		Integer result = future.get();
		System.out.printf("main---end... 结果是：%d ",result);
	}	
}

运行结果

代码二

public class ThreadTest {

	public static ExecutorService executor = Executors.newFixedThreadPool(10);
	
	public static void main(String[] args) throws Exception {
		System.out.println("main---start");
		CompletableFuture<Integer> future = CompletableFuture.supplyAsync(()->{
			System.out.printf("当前线程  %d \n",Thread.currentThread().getId());
			int i = 10/0;
			System.out.printf("运行结果：%d \n",i);
			return i;
			//handle比whenComplete更强大，可以处理结果
		}, executor).handle((result,exception)->{
			if(result != null) {
				return result*2;
			}
			if(exception != null) {
				return 1990;
			}
			return -1;
		});
		Integer result = future.get();
		System.out.printf("main---end... 结果是：%d ",result);
	}	
}

运行结果

代码三

public class ThreadDemo {
	
	public static ExecutorService executor = Executors.newFixedThreadPool(10);

	public static void main(String[] args) throws Exception{
		System.out.println("main...start...");
		/**
		 * 线程串行化
		 * 1、thenRunAsync：不能获取上一步的执行结果，无返回值
		 * 
		 CompletableFuture.supplyAsync(() -> {
			System.out.println("当前线程：" + Thread.currentThread().getId());
			int i = 10 / 2;
			System.out.println("运行结果：" + i);
			return i;
		}, executor).thenRunAsync(() -> {
			System.out.println("任务2启动了");
		}, executor);
		
		   2、thenAcceptAsync：能接收上一步的结果，但是无返回值
		   
		   CompletableFuture.supplyAsync(() -> {
			System.out.println("当前线程：" + Thread.currentThread().getId());
			int i = 10 / 2;
			System.out.println("运行结果：" + i);
			return i;
		}, executor).thenAcceptAsync(res -> {
			System.out.println("任务2启动了 " + res);
		}, executor);
		
			3、thenApplyAsync：能接收上一步的结果，有返回值
			
			thenApplyAsync(res -> {
			System.out.println("任务2启动了 " + res);
			return res * 3;
		}, executor)
		 */
		CompletableFuture<Integer> future = CompletableFuture.supplyAsync(() -> {
			System.out.println("当前线程：" + Thread.currentThread().getId());
			int i = 10 / 2;
			System.out.println("运行结果：" + i);
			return i;
		}, executor).thenApplyAsync(res -> {
			System.out.println("任务2启动了 " + res);
			return res * 3;
		}, executor);
		System.out.println("main...end..." + future.get());
	}
}

运行结果

代码四

public class ThreadDemo {
	
	public static ExecutorService executor = Executors.newFixedThreadPool(10);

	public static void main(String[] args) throws Exception{
		System.out.println("main...start...");
		
		/**
		 * 两个都完成
		 */
		CompletableFuture<Integer> future01 = CompletableFuture.supplyAsync(() -> {
			System.out.println("任务1线程：" + Thread.currentThread().getId());
			int i = 10 / 2;
			System.out.println("任务1结束");
			return i;
		}, executor);
		
		CompletableFuture<String> future02 = CompletableFuture.supplyAsync(() -> {
			System.out.println("任务2线程：" + Thread.currentThread().getId());
			System.out.println("任务2结束");
			return "Hello";
		}, executor);
		
		//无返回结果，取不到结果
//		future01.runAfterBothAsync(future02, () -> {
//			System.out.println("任务3开始...");
//		}, executor);
		
		//无返回结果，可以取到结果，但不能返回
//		future01.thenAcceptBothAsync(future02, (f1,f2) -> {
//			System.out.println("任务3开始。。。汇总了任务1和2的结果：" + f2 + " " + f1);
//		}, executor);
		
		//有返回结果，可以取到结果，可以返回
		CompletableFuture<String> future = future01.thenCombineAsync(future02, (f1,f2) -> {
			return f2 + f1 + " 你好...";
		}, executor);
		System.out.println("main...end..." + future.get());
	}
}

运行结果

代码五

public class ThreadDemo {
	
	public static ExecutorService executor = Executors.newFixedThreadPool(10);

	public static void main(String[] args) throws Exception{
		System.out.println("main...start...");
		
		CompletableFuture<Object> future01 = CompletableFuture.supplyAsync(() -> {
			System.out.println("任务1线程：" + Thread.currentThread().getId());
			int i = 10 / 2;
			System.out.println("任务1结束");
			return i;
		}, executor);
		
		CompletableFuture<Object> future02 = CompletableFuture.supplyAsync(() -> {
			System.out.println("任务2线程：" + Thread.currentThread().getId());
			try {
				TimeUnit.SECONDS.sleep(3);
			} catch (Exception e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			System.out.println("任务2结束");
			return "Hello";
		}, executor);
		
		/**
		 * 两个都完成只要有一个完成，就执行任务3
		 * runAfterEitherAsync ：不感知结果，无返回值
		 * acceptEitherAsync ：感知结果，有返回值
		 */
//		future01.runAfterEitherAsync(future02, ()->{
//			System.out.println("任务3开始");
//		},executor);
//		future01.acceptEitherAsync(future02, res -> {
//			System.out.println("任务3 " + res);
//		}, executor);
		CompletableFuture<String> future = future01.applyToEitherAsync(future02, (res) -> {
			return "fuck " + res;
		}, executor);
		
		System.out.println("main...end..." + future.get());
	}
}

运行结果

代码六

public class ThreadDemo {
	
	public static ExecutorService executor = Executors.newFixedThreadPool(10);

	public static void main(String[] args) throws Exception{
		System.out.println("main...start...");
		CompletableFuture<String> futureImg = CompletableFuture.supplyAsync(() -> {
			System.out.println("查询商品的图片信息");
			return "hello.jpg";
		}, executor);
		CompletableFuture<String> futureAttr = CompletableFuture.supplyAsync(() -> {
			try {
				TimeUnit.SECONDS.sleep(3);
			} catch (Exception e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			System.out.println("查询商品的属性");
			return "黑色  + 256G";
		}, executor);
		CompletableFuture<String> futureDesc = CompletableFuture.supplyAsync(() -> {
			System.out.println("查询商品介绍");
			return "华为";
		}, executor);
		
		//必须之前所有任务都成功
//		CompletableFuture<Void> future = CompletableFuture.allOf(futureImg,futureAttr,futureDesc);
		//只要有一个成功就可以
		CompletableFuture<Object> future = CompletableFuture.anyOf(futureImg,futureAttr,futureDesc);
		//等待所有任务完成
		future.get();
//		System.out.println("main...end..." + futureImg.get() + "_" + futureAttr.get() + "_" + futureDesc.get());
		System.out.println("main...end...结果:" + future.get());
	}
}

运行结果

参考博客：
https://mp.weixin.qq.com/s?__biz=Mzg3NzU5NTIwNg==&mid=2247490456&idx=1&sn=95836324db57673a4d7aea4fb233c0d2&chksm=cf21c4b1f8564da72dc7b39279362bcf965b1374540f3b339413d138599f7de59a5f977e3b0e&mpshare=1&scene=1&srcid=05216AhbyPfYI9jZONs8b0N7&sharer_sharetime=1662776308715&sharer_shareid=d8593a58e3ccb2c2182cb847784a1e12#rd