java - Spring RestTemplate - 异步与同步 restTemplate

Question

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 2806 毫秒内返回:

ArrayList<String> references = new ArrayList<>();
ArrayList<String> links = new ArrayList<>();
RestTemplate restTemplate = new RestTemplate(); 
restTemplate.getMessageConverters().add(new StringHttpMessageConverter());
for (int i = 0; i < 10; i++) {
    ResponseEntity<String> resource = restTemplate.getForEntity(references.get(i), String.class);
    links.add(resource.getBody().toString());
}

RestTemplate - 异步并在 2794 毫秒内返回:

//Creating a synchronizedList so that when the async resttemplate returns, there will be no concurrency issues
List<String> links = Collections.synchronizedList(new ArrayList<String>());

//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<String> references = new ArrayList<>();
ArrayList<String> links = new ArrayList<>();
AsyncRestTemplate asyncRestTemplate = new AsyncRestTemplate(customClientHttpRequestFactory); 
restTemplate.getMessageConverters().add(new StringHttpMessageConverter());
for (int i = 0; i < 10; i++) {
    Future<ResponseEntity<String>> resource = asyncRestTemplate.getForEntity(references.get(i), String.class);
    ResponseEntity<String> 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，这两种方法实际上以非常相似的时间返回结果，在异步和同步调用中平均为 2800 毫秒。

我是否做错了什么，因为我希望异步调用更快？

Answer 1

现在，AsyncRestTemplate 是 @Deprecated，有利于 WebClient。所以没有人应该再使用那个类了!

https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/web/reactive/function/client/WebClient.html