Rest API Automation in Java – Get Method

Using Rest-assured and TestNG

In this post, we will learn to automate REST APIs using the Rest-Assured library and TestNG. Rest Assured is a Java library using which we can test and validate the REST web services. Although Rest-assured provides its own validating mechanism(assertions for validating response) but we can combine Rest-assured with TestNG to get the best of both the libraries.

During the course of this tutorial, we will be using the following-

• Sample Rest API to be used in Automation – RestCountries API
• Rest-Assured and its dependencies (https://code.google.com/p/rest-assured/wiki/Downloads) (Remember to download and add to the class path, the other dependencies also). POM dependencies for the Rest Assured and its dependencies-

<dependency>
    <groupId>com.jayway.restassured</groupId>
    <artifactId>rest-assured</artifactId>
    <version>2.3.4</version>
</dependency>

<dependency>
	<groupId>org.codehaus.groovy</groupId>
	<artifactId>groovy-all</artifactId>
	<version>2.3.5</version>
</dependency>

• TestNG as a testing framework
  

Rest API Get Method Automation in Java

In the following example, we are using the Rest-assured library’s “get” method to make an HTTP Get request to the restcountries.eu API- http://restcountries.eu/rest/v1/name/{countryName} that fetches the capital of a country. Then we will fetch the response in JSONArray and use TestNG’s assert method for validation.

You can also download the RestAPI Automation sample script from API Automation Script.

package RestAPITest;

import static com.jayway.restassured.RestAssured.get;

import org.json.JSONArray;
import org.json.JSONException;
import org.testng.Assert;
import org.testng.annotations.Test;

import com.jayway.restassured.response.Response;

public class RestTest {

 @Test
 public void getRequestFindCapital() throws JSONException {
 
 //make get request to fetch capital of norway
 Response resp = get("http://restcountries.eu/rest/v1/name/norway");
 
 //Fetching response in JSON
 JSONArray jsonResponse = new JSONArray(resp.asString());
 
 //Fetching value of capital parameter
 String capital = jsonResponse.getJSONObject(0).getString("capital");
 
 //Asserting that capital of Norway is Oslo
 Assert.assertEquals(capital, "Oslo");
 }
 
}

In our next tutorial – Rest API POST method automation in Java, we will study the HTTP post method automation using the Rest-assured library in Java.

Kuldeep Rana

Kuldeep is the founder and lead author of ArtOfTesting. He is skilled in test automation, performance testing, big data, and CI-CD. He brings his decade of experience to his current role where he is dedicated to educating the QA professionals. You can find him on LinkedIn.