Handling multiple query parameters in REST Assured can seem a bit challenging at first, but it's quite straightforward once you know the basics. REST Assured provides a clean and intuitive way to construct requests with various parameters effortlessly. Here's a simple breakdown and example to help you get started.

Understanding Query Parameters

Query parameters are key-value pairs sent in the URL after a question mark ?. For example, in the URL https://api.example.com/items?category=books&sort=asc, category and sort are query parameters. You can pass multiple query parameters by separating them with an ampersand &.

Setting Up REST Assured

Before you begin, make sure that you have added REST Assured as a dependency in your project. For example, with Maven, you can include the following in your pom.xml:

<dependency>
    <groupId>io.rest-assured</groupId>
    <artifactId>rest-assured</artifactId>
    <version>5.4.0</version> <!-- Check for the latest version -->
    <scope>test</scope>
</dependency>

Making Requests with Multiple Query Parameters

You can handle multiple query parameters in REST Assured using the queryParam() method. Here’s how to do it:

import io.restassured.RestAssured;
import io.restassured.response.Response;

public class QueryParametersExample {
    public static void main(String[] args) {
        // Set the base URI
        RestAssured.baseURI = "https://api.example.com";

        // Making a GET request with multiple query parameters
        Response response = RestAssured.given()
            .queryParam("category", "books")
            .queryParam("sort", "asc")
            .queryParam("price_min", "10")
            .queryParam("price_max", "100")
            .when()
            .get("/items");

        // Print the response
        System.out.println("Response: " + response.getBody().asString());
        System.out.println("Status Code: " + response.getStatusCode());
    }
}

Explanation of the Code

1. Base URI: Set the base URI of the API you want to test using RestAssured.baseURI. Ensure the URI is the correct endpoint for your API.

2. Query Parameters: Use the queryParam() method to append your query parameters. You can call queryParam() multiple times to add as many parameters as needed.

3. HTTP Request: After adding the query parameters, you specify the type of request you want to make, using the when() method followed by chaining with get() to perform a GET request.

4. Response Handling: The response from the server can be captured in a Response object. You can then print out the body of the response and the status code using getBody().asString() and getStatusCode() respectively.

Testing Different Combinations

Testing different combinations of query parameters is crucial for comprehensive API testing. You can loop through a set of parameters or use parameterized tests to systematically validate the desired outcomes.

Conclusion

When handling multiple query parameters in REST Assured, the key is to take advantage of the queryParam() method for a clean and robust way to build your requests. With practice, adding and testing query parameters will become a natural part of your API testing flow.

By following the simple steps outlined in this guide, exchanging data with RESTful web services using multiple query parameters can be an easy and effective task for any Java developer.