First of all, you should ask from developers the API Documentation and understand it. Then prioritize the cases after discussion with them.
I would suggest using Rest Assured which is a Java Library to test Rest API.
You can integrate it with your existing UI Testing Framework if you have one. Below is the example of automating GET Request using Rest Assured:
import org.testng.Assert;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.Test;
import static com.jayway.restassured.RestAssured.*;
import com.jayway.restassured.RestAssured;
import com.jayway.restassured.response.Response;
public class GetStatusCodeTest {
@BeforeClass
public void setBaseUri () {
RestAssured.baseURI = "https://maps.googleapis.com";
}
@Test
public void testStatusCode () {
Response res =
given ()
.param ("query", "restaurants in mumbai")
.param ("key", "Xyz")
.when()
.get ("/maps/api/place/textsearch/json");
Assert.assertEquals (res.statusCode (), 200);
}
}
Here we check whether the response code is 200. If yes then the test has passed.
A detailed tutorial on Rest Assured can be found at below link:
https://restservicestesting.blogspot.in/
SOAPUI
forSOAP
webservice and not forREST
ones? (Have only worked with it againstSOAP
)