More API requests

In this section, we will explore how to send advanced API requests using REST Assured. You will learn how to:

Add headers, query parameters, and path parameters.
Send POST, PUT, PATCH, and DELETE requests with JSON payloads.
Handle different content types like JSON and XML.

Adding Headers, Query Parameters, and Path Parameters

In REST APIs, we often need to add extra information to our requests. Let’s break down these parts:

Adding Headers

Headers provide additional information about the request (e.g., content type, authentication).

Example: Setting the Content-Type header to application/json:

Java

Copy

given()
    .header("Content-Type", "application/json")
.when()
    .get("/books/20250401")
.then()
    .statusCode(200);

Common Headers in REST APIs:

Header	Purpose
Content-Type	Tells the server the request format (e.g., JSON, XML)
Authorization	Sends security tokens (e.g., Bearer token)
Accept	Tells the server what response format you expect

Adding Query Parameters

Query parameters are part of the URL and filter or modify the request.

Example: /books/?language=English(Get English Books))

In REST Assured:

Java

Copy

given()
    .queryParam("language", "English")
.when()
    .get("/books")
.then()
    .statusCode(200);

Adding Path Parameters

Path parameters are part of the URL and represent specific resources.

Example: /books/20250401 (Get book with ISBN 20250401)

In REST Assured:

Java

Copy

given()
    .pathParam("isbn", 20250401)
.when()
    .get("/books/{isbn}")
.then()
    .statusCode(200);

Sending POST, PUT, PATCH, and DELETE Requests

Now, let's work with these HTTP methods:

Sending a POST Request (Create Data)

Example: Add a new book with a JSON payload.

Step 1: Prepare the JSON Payload

Java

Copy

String requestBody = """
{
    "name": "Book 2",
    "language": "English",
    "price": 200,
    "publisher": "ABC publisher"
}
""";

Step 2: Send the POST Request

Java

Copy

given()
    .header("Content-Type", "application/json")
    .body(requestBody)
.when()
    .post("/books")
.then()
    .statusCode(201)  // 201 = Created
    .body("name", equalTo("book 2"));

Sending a PUT Request (Update Data)

Example: Update all book details.

Java

Copy

String updateBook = """
{
    "name": "book 2 Updated",
    "language": "Spanish",
    "price": 300.00,
    "publisher": "XYZ publisher"
}
""";

given()
    .header("Content-Type", "application/json")
    .body(updateBook)
    .pathParam("isbn", 20250401)
.when()
    .put("/books/{isbn}")
.then()
    .statusCode(200)
    .body("name", equalTo("book 2 Updated"));

Sending a PATCH Request (Modify Data)

Example: Update only the name of a book.

Java

Copy

String partialUpdate = """
{
    "name": "book 2 Patched"
}
""";

given()
    .header("Content-Type", "application/json")
    .body(partialUpdate)
    .pathParam("isbn", 20250401)
.when()
    .patch("/books/{isbn}")
.then()
    .statusCode(200)
    .body("name", equalTo("Book 2 Patched"));

Sending a DELETE Request (Remove Data)

Example: Delete a book by ISBN.

Java

Copy

given()
    .pathParam("isbn", 20250401)
.when()
    .delete("/books/{id}")
.then()
    .statusCode(204);

Handling Different Content Types (JSON and XML)

APIs may return data in various formats like JSON and XML. REST Assured can handle both.

Working with JSON Responses

Example: Validate a JSON response.

Java

Copy

given()
    .accept("application/json")
.when()
    .get("/books/20250401")
.then()
    .statusCode(200)
    .body("name", equalTo("Book 1"));

Working with XML Responses

Some APIs return XML instead of JSON. REST Assured can handle XML validation using XPath.

Example XML Response:

Java

Copy

<book>
    <id>20250401</id>
    <name>Book 1</name>
    <language>English</language>
    <price>200.00</price>
    <publisher>ABC publisher</publisher>
</book>

Request XML Response

Java

Copy

given()
    .accept("application/xml")
.when()
    .get("/books/20250401")
.then()
    .statusCode(200)
    .body("book.name", equalTo("Book 1"));

Combining Headers, Parameters, and Body

You can mix headers, query/path parameters, and body in one request.

Example: Update a book with query parameters and JSON body.

Java

Copy

String updatedBook = """
{
    "name": "Updated Book"
}
""";

given()
    .header("Content-Type", "application/json")
    .queryParam("language", "English")
    .pathParam("isbn", 20250401)
    .body(updatedbook)
.when()
    .put("/books/{id}")
.then()
    .statusCode(200)
    .body("name", equalTo("Updated Book"));

Error Handling and Validating Responses

When working with APIs, handle common errors like 404 (Not Found) and 400 (Bad Request).

Example: Handle a missing book.

Java

Copy

given()
    .pathParam("isbn", 123)
.when()
    .get("/books/{isbn}")
.then()
    .statusCode(404);