completablefuture.join方法

`CompletableFuture.join()` 方法是一个阻塞方法，它会等待 `CompletableFuture` 的计算完成并返回结果。如果 `CompletableFuture` 的计算已经完成，它会立即返回结果，否则它会一直阻塞直到计算完成。

以下是一个使用 `CompletableFuture.join()` 方法的例子：

CompletableFuture<String> future = CompletableFuture.supplyAsync(() -> {
    // 模拟一个长时间的计算
    try {
        Thread.sleep(1000);
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
    return "Hello";
});

String result = future.join(); // 阻塞等待计算完成并返回结果

System.out.println(result); // 输出：Hello

在上面的例子中，我们使用 `CompletableFuture.supplyAsync()` 方法创建了一个异步计算任务，并返回一个 `CompletableFuture` 对象。然后我们调用 `join()` 方法等待计算完成并返回结果。

相关问题

CompletableFuture.join

CompletableFuture.join()是一个阻塞方法，会等待Future的完成，返回Future的结果或者抛出Future的异常。具体而言，如果Future已经完成，那么join()立即返回结果；否则，join()会让当前线程阻塞，直到Future完成，然后返回结果或者抛出异常。它通常用于等待异步操作完成，然后获取其结果。

completableFuture.join

CompletableFuture.join() is a method in Java's CompletableFuture class that blocks the current thread until the CompletableFuture has completed its computation and returns the result of the computation. It is similar to calling get() method, but with one important difference: join() does not throw checked exceptions, so it can be used in lambda expressions and method references that do not declare any checked exceptions.

Here is an example of using join() method:

CompletableFuture<String> future = CompletableFuture.supplyAsync(() -> {
    return "Hello";
});

String result = future.join();
System.out.println(result);

In this example, we create a CompletableFuture that returns the string "Hello" asynchronously using the supplyAsync() method. We then call the join() method on the CompletableFuture to block the current thread until the computation is completed and get the result of the computation. Finally, we print the result "Hello" to the console.