java sync和async区别_java – Spring RestTemplate – async vs sync rest...

我编写了以下代码来测试同步RestTemplate和AsyncRestTemplate的性能.我只是在POSTMAN上手动运行了几次.

我们只是将10个引用传递给GET调用,以便我们可以返回10个链接：

RestTemplate – 同步并在2806ms返回：

ArrayList references = new ArrayList<>();

ArrayList links = new ArrayList<>();

RestTemplate restTemplate = new RestTemplate();

restTemplate.getMessageConverters().add(new StringHttpMessageConverter());

for (int i = 0; i < 10; i++) {

ResponseEntity resource = restTemplate.getForEntity(references.get(i), String.class);

links.add(resource.getBody().toString());

}

RestTemplate – 异步并返回2794ms：

//Creating a synchronizedList so that when the async resttemplate returns, there will be no concurrency issues

List links = Collections.synchronizedList(new ArrayList());

//CustomClientHttpRequestFactory just extends SimpleClientHttpRequestFactory but disables automatic redirects in SimpleClientHttpRequestFactory

CustomClientHttpRequestFactory customClientHttpRequestFactory = new CustomClientHttpRequestFactory();

//Setting the ThreadPoolTaskExecutor for the Async calls

org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor pool = new org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor();

pool.setCorePoolSize(5);

pool.setMaxPoolSize(10);

pool.setWaitForTasksToCompleteOnShutdown(true);

pool.initialize();

//Setting the TaskExecutor to the ThreadPoolTaskExecutor

customClientHttpRequestFactory.setTaskExecutor(pool);

ArrayList references = new ArrayList<>();

ArrayList links = new ArrayList<>();

AsyncRestTemplate asyncRestTemplate = new AsyncRestTemplate(customClientHttpRequestFactory);

restTemplate.getMessageConverters().add(new StringHttpMessageConverter());

for (int i = 0; i < 10; i++) {

Future> resource = asyncRestTemplate.getForEntity(references.get(i), String.class);

ResponseEntity entity = resource.get(); //this should start up 10 threads to get the links asynchronously

links.add(entity.getBody().toString());

}

在大多数情况下,两种方法实际上都以非常相似的时间返回结果,在异步和同步调用中平均为2800ms.

我做错了什么,因为我希望异步调用更快？