AWS SDK - 异步配置的目的 SdkAdvancedAsyncClientOption.

Question

asyncConfiguration 的目的是什么 SdkAdvancedAsyncClientOption.FUTURE_COMPLETION_EXECUTOR？我们应该在哪些用例中使用它？从 java doc 上FUTURE_COMPLETION_EXECUTOR，我看到：Configure the executor that should be used to complete the CompletableFuture that is returned by the service clients.我认为后续对CompletableFuture异步结果的调用将在传入的执行程序上执行FUTURE_COMPLETION_EXECUTOR，但事实并非如此。ClientAsyncConfiguration.Builder asyncConfig = ClientAsyncConfiguration.builder()        .advancedOption(SdkAdvancedAsyncClientOption.FUTURE_COMPLETION_EXECUTOR, customExecutor);SnsAsyncClient.builder()        .asyncConfiguration(asyncConfig.build())        .build();异步请求示例：snsAsyncClient.publish(publishRequest).thenApplyAsync(..);

Answer 1

AWS SDK 异步请求返回CompletableFuture。默认情况下，对返回实例的调用thenApply(..)和对返回实例的调用将在类似线程上执行。async配置的思路是提供线程池executor，用于后续对like和 的调用。该执行器将不会应用于像和由于实现这样的方法（如果未将执行器传递给，它将默认使用，或者我们可以将自定义执行器作为第二个方法参数传递）。whenComplete(..)CompletableFuturesdk-async-response-0-XSdkAdvancedAsyncClientOption.FUTURE_COMPLETION_EXECUTORCompletableFuturethenApply(..)whenComplete(..)thenApplyAsyncwhenCompleteAsyncCompletableFuturethenApplyAsync(..)ForkJoinPool.commonPool()

snsAsyncClient.publish(publishRequest)
        .thenApply(..)
        .whenComplete(..);

内部代码thenApply，whenComplete将在配置的执行程序上处理SdkAdvancedAsyncClientOption.FUTURE_COMPLETION_EXECUTOR。