Request Specifications

As your API tests become more complex, you will need to customize your requests with headers, query parameters, cookies, and more. REST Assured provides a powerful feature called Request Specification to make your tests cleaner and easier to maintain.

What is a Request Specification?

A Request Specification in REST Assured allows you to define reusable settings for API requests. This helps you avoid writing the same code repeatedly for every test.

With Request Specification, you can:

Set base URIs and endpoints.
Add headers, query parameters, and cookies.
Reuse these settings across multiple tests.

Why Use Request Specifications?

Avoid Code Duplication – Define common settings once.
Improve Readability – Keep your tests clean and simple.
Increase Flexibility – Easily update settings in one place.

Example Scenario

Let's say you want to test an API that requires:

Base URL: http://1xx.xxx.xx.xxx:8080
Content Type: application/json

Instead of adding these details to every test, we'll use a Request Specification.

Create a Request Specification

Here's how to define a Request Specification:

Java

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import io.restassured.RestAssured;
import io.restassured.specification.RequestSpecification;
import io.restassured.response.Response;
import static io.restassured.RestAssured.*;
import static org.hamcrest.Matchers.*;

public class AdvancedRequestSpec {

    public static void main(String[] args) {

        // Create a reusable Request Specification
        RequestSpecification requestSpec = given()
                .baseUri("http://1xx.xxx.xx.xxx:8080")
                .contentType("application/json");

        // Use the Request Specification to send a GET request
        Response response = given()
                .spec(requestSpec) // Reuse the specification
                .when()
                .get("/books/20250401");

        // Validate and print the response
        response.then().statusCode(200);
        System.out.println("Response: " + response.getBody().asString());
    }
}

Understanding the Code

Let's break down the important parts:

1. Create the Request Specification

Java

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RequestSpecification requestSpec = given()
    .baseUri("http://1xx.xxx.xx.xxx:8080")
    .contentType("application/json");

baseUri() – Defines the API's base URL.
contentType() – Specifies the content format (JSON).

2. Reuse the Specification

given().spec(requestSpec).when().get("/books/20250401");

spec() – Applies the reusable request configuration.

Adding Query Parameters

Use query parameters to filter results or customize the request.

Example:

Fetch Books with the book name Book1:

Java

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RequestSpecification requestSpec = given()
    .baseUri("http://1xx.xxx.xx.xxx:8080")
    .queryParam("name", "Book 1");

Response response = given()
    .spec(requestSpec)
    .when()
    .get("/books");

response.then().statusCode(200);
System.out.println("Filtered Response: " + response.getBody().asString());

Adding Path Parameters

Use path parameters to specify dynamic parts of a URL.

Example:

Get details for book with ISBN 20250401:

Java

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RequestSpecification requestSpec = given()
    .baseUri("http://1xx.xxx.xx.xxx:8080");

Response response = given()
    .spec(requestSpec)
    .pathParam("isbn", 20250401) // Set the path parameter
    .when()
    .get("/books/{isbn}");

response.then().statusCode(200);
System.out.println("Book Details: " + response.getBody().asString());

Adding Cookies

Some APIs require cookies for authentication or tracking.

Example

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RequestSpecification requestSpec = given()
    .baseUri("https://example.com")
    .cookie("sessionId", "abc123");

Response response = given()
    .spec(requestSpec)
    .when()
    .get("/profile");

response.then().statusCode(200);
System.out.println("Cookie Response: " + response.getBody().asString());

Logging Requests and Responses

Enable logging to debug and view API request and response details.

Example:

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RequestSpecification requestSpec = given()
    .baseUri("http://1xx.xxx.xx.xxx:8080")
    .log().all(); // Log request details

Response response = given()
    .spec(requestSpec)
    .when()
    .get("/books/20250401");

response.then().log().all(); // Log response details

Reusing Request Specifications in Multiple Tests

You can extract your Request Specification into a reusable method.

Example:

Java

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public class ApiUtils {

    public static RequestSpecification getRequestSpec() {
        return given()
                .baseUri("http://1xx.xxx.xx.xxx:8080")
                .contentType("application/json");
    }
}

public class BooksTests {
    public static void main(String[] args) {

        // Use the reusable Request Specification
        Response response = given()
                .spec(ApiUtils.getRequestSpec())
                .when()
                .get("/books/20250401");

        response.then().statusCode(200);
        System.out.println("Book Data: " + response.getBody().asString());
    }
}

Combining Multiple Specifications

You can merge different parts of the request using .spec() multiple times.

Example:

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RequestSpecification baseSpec = given()
    .baseUri("http://1xx.xxx.xx.xxx:8080");

RequestSpecification authSpec = given()
    .header("Authorization", "Bearer token123");

Response response = given()
    .spec(baseSpec)
    .spec(authSpec)
    .when()
    .get("/books/20250401");

response.then().statusCode(200);