Search⌘ K
AI Features
Home
Courses
Learn REST and SOAP API Test Automation in Java

Async Requests

Explore how to handle asynchronous requests in REST API automation using Rest Assured along with the AsyncHttpClient library. Understand the difference between synchronous and asynchronous calls, how to implement async requests in Java, manage timeouts, and retrieve responses effectively in test automation scenarios.

We'll cover the following...

What is an async request?

Synchronous request blocks the execution of server code until the response is received, whereas asynchronous request (async in short), does not block the execution and returns a callback to the client which can be used to receive the actual data once the execution is complete.

Handling async requests

REST Assured does not support async requests out of the box. We can automate these use cases using a third-party open-source library.

We will be using asynchttpclient for the same and to use this, let’s add below dependency to our build file.

Maven

Add this in the pom.xml file:

<dependency>
    <groupId>org.asynchttpclient</groupId>
    <artifactId>async-http-client</artifactId>
    <version>2.12.0</version>
</dependency>

Gradle

Add this in the build.gradle file:

compile group: 'org.asynchttpclient', name: 'async-http-client', version: '2.12.0'

Let’s now understand how we can handle async requests using the code below:

Java
import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import org.testng.annotations.Test;

import org.asynchttpclient.Dsl;

import java.util.concurrent.Future;

import org.asynchttpclient.Response;

import java.util.concurrent.TimeoutException;

import java.util.concurrent.ExecutionException;



public class APIDemo {



	private static Logger LOG = LoggerFactory.getLogger(APIDemo.class);



	static {

		// setting logger to INFO to disable unwanted http client logs

		((ch.qos.logback.classic.Logger) org.slf4j.LoggerFactory

				.getLogger(ch.qos.logback.classic.Logger.ROOT_LOGGER_NAME))

						.setLevel(ch.qos.logback.classic.Level.INFO);

	}



	@Test

	public void asyncTest() throws InterruptedException, ExecutionException, TimeoutException {



		String url = "https://reqres.in/api/users?delay=3";



		Future<Response> whenResponse = Dsl.asyncHttpClient().prepareGet(url).execute();

		

		Response response = whenResponse.get();	

		LOG.info(response.getResponseBody());

	}

}

Let’s understand the code above

  • Target URL sends back the response after a delay of 3 secs

    String url = "https://reqres.in/api/users?delay=3";

  • Creates an object of Future of type Response and makes a GET call using the prepareGet(url) method

    Future<Response> whenResponse = Dsl.asyncHttpClient().prepareGet(url).execute();

  • Using the Future Response above, it waits if necessary, for the computation to complete, and then retrieves its result until the future returns response

    Response response = whenResponse.get();

    To wait with a maximum timeout, we can use the code below:

    Response response = whenResponse.get(10, TimeUnit.SECONDS);

    If Future does not complete (or if we don’t receive response) with 10 seconds, we get java.util.concurrent.TimeoutException.

In the next lesson, we will learn about proxy server settings.