runAsync:无入参、无返回值
CompletableFuture.runAsync() 方法用于执行没有返回值的任务。
public class CompletableFutureRunAsyncDemo {
public static void main(String[] args) {
ExecutorService executor = Executors.newFixedThreadPool(5);
System.out.println("main start ...");
CompletableFuture<Void> future = CompletableFuture.runAsync(() -> {
System.out.println("开启异步任务...");
}, executor);
System.out.println("main end ...");
executor.shutdown();
}
}
执行结果：
main start ...
main end ...
开启异步任务...
supplyAsync ：无入参，可以获取返回值
使用CompletableFuture.supplyAsync() 方法来创建 CompletableFuture 对象的示例
public class CompletableFutureSupplyAsyncDemo {
public static void main(String[] args) throws Exception {
ExecutorService executor = Executors.newFixedThreadPool(5);
System.out.println("main start ...");
CompletableFuture<String> future = CompletableFuture.supplyAsync(() -> {
System.out.println("开启异步任务...");
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
return "开启异步任务,我是返回值";
}, executor);
System.out.println("main here are not blocked ...");
System.out.println("获取异步任务返回值：" + future.get());
System.out.println("main end ...");
executor.shutdown();
}
}
执行结果：
main start ...
main here are not blocked ...
开启异步任务...
获取异步任务返回值：开启异步任务,我是返回值
main end ...
