As a part of End to End REST Assured Tutorial, in this post, we will learn to why and how to set the Content-Type header in Rest Assured for a request.
Content-Type is a header that indicates the media type or MIME( Multipurpose Internet Mail Extensions ) type or type of a file. When we hit any POST or PUT API requests we may need to pass a payload. That payload can be in any supported format by API such as XML, JSON, etc. We need to use the Content-Type header to let the server know the format of the payload for a request which will be sent.
Similarly, Content-Type for response indicates the format of the response returned. It is not mandatory that the Content-Type of request and response should be the same.
I have used below dependency of Rest Assured library for this post:-
io.rest-assured rest-assured 4.3.1 test
Postman tool automatically adds a Content-Type header based on the request body we select. For example, if select request body format as JSON then Postman will add automatically a header named “Content-Type” with value as “application/json“. This does not happen automatically in Rest Assured and you may get an unexpected response as a server may not identify the format of payload.
Let’s see an example where we are not setting up Content-Type explicitly. We are passing a payload which is in a JSON format.
package RestAssuredBasicConcepts;
import org.testng.annotations.Test;
import io.restassured.RestAssured;
public class SetContentTypeForRequest {
@Test
public void WIthoutSettingContentType()
{
RestAssured
.given()
.log()
.all()
.body("{\r\n" +
" \"firstname\" : \"Jim\",\r\n" +
" \"lastname\" : \"Brown\",\r\n" +
" \"totalprice\" : 111,\r\n" +
" \"depositpaid\" : true,\r\n" +
" \"bookingdates\" : {\r\n" +
" \"checkin\" : \"2018-01-01\",\r\n" +
" \"checkout\" : \"2019-01-01\"\r\n" +
" },\r\n" +
" \"additionalneeds\" : \"Breakfast\"\r\n" +
"}")
.post("https://restful-booker.herokuapp.com/booking")
.then()
.log()
.all();
}
}
Output
[RemoteTestNG] detected TestNG version 7.0.1
Request method: POST
Request URI: https://restful-booker.herokuapp.com/booking
Proxy:
Request params:
Query params:
Form params:
Path params:
Headers: Accept=*/* Content-Type=text/plain; charset=ISO-8859-1
Cookies:
Multiparts:
Body:
{ "firstname" : "Jim", "lastname" : "Brown", "totalprice" : 111, "depositpaid" : true, "bookingdates" : { "checkin" : "2018-01-01", "checkout" : "2019-01-01" }, "additionalneeds" : "Breakfast"
}
HTTP/1.1 500 Internal Server Error
Server: Cowboy
Connection: keep-alive
X-Powered-By: Express
Content-Type: text/plain; charset=utf-8
Content-Length: 21
Etag: W/"15-/6VXivhc2MKdLfIkLcUE47K6aH0"
Date: Tue, 29 Sep 2020 07:42:56 GMT
Via: 1.1 vegur Internal Server Error
PASSED: WIthoutSettingContentType =============================================== Default test Tests run: 1, Failures: 0, Skips: 0
=============================================== ===============================================
Default suite
Total tests run: 1, Passes: 1, Failures: 0, Skips: 0
===============================================
We are passing a JSON payload to request but observe in output that it takes Content-Type as “text/plain” and return a response as “Internal server error“. Sever could not understand the correct format of the request payload and failed. This is the reason we should set Content-Type for a request properly.
As Content-Type is a header we can pass it as a key-value pair using methods discussed here. An example is as below:-
package RestAssuredBasicConcepts;
import org.testng.annotations.Test;
import io.restassured.RestAssured;
public class SetContentTypeForRequest {
@Test
public void settingContentTypeAsHeader()
{
RestAssured
.given()
.log()
.all()
.header("Content-Type", "application/json")
.body("{\r\n" +
" \"firstname\" : \"Jim\",\r\n" +
" \"lastname\" : \"Brown\",\r\n" +
" \"totalprice\" : 111,\r\n" +
" \"depositpaid\" : true,\r\n" +
" \"bookingdates\" : {\r\n" +
" \"checkin\" : \"2018-01-01\",\r\n" +
" \"checkout\" : \"2019-01-01\"\r\n" +
" },\r\n" +
" \"additionalneeds\" : \"Breakfast\"\r\n" +
"}")
.post("https://restful-booker.herokuapp.com/booking")
.then()
.log()
.all();
}
}
Output
[RemoteTestNG] detected TestNG version 7.0.1
Request method: POST
Request URI: https://restful-booker.herokuapp.com/booking
Proxy:
Request params:
Query params:
Form params:
Path params:
Headers: Accept=*/* Content-Type=application/json; charset=UTF-8
Cookies:
Multiparts:
Body:
{ "firstname": "Jim", "lastname": "Brown", "totalprice": 111, "depositpaid": true, "bookingdates": { "checkin": "2018-01-01", "checkout": "2019-01-01" }, "additionalneeds": "Breakfast"
}
HTTP/1.1 200 OK
Server: Cowboy
Connection: keep-alive
X-Powered-By: Express
Content-Type: application/json; charset=utf-8
Content-Length: 195
Etag: W/"c3-E5R+AIhAHdRg+t7MhfO18uLvLAw"
Date: Tue, 29 Sep 2020 07:52:19 GMT
Via: 1.1 vegur { "bookingid": 21, "booking": { "firstname": "Jim", "lastname": "Brown", "totalprice": 111, "depositpaid": true, "bookingdates": { "checkin": "2018-01-01", "checkout": "2019-01-01" }, "additionalneeds": "Breakfast" }
}
PASSED: WIthoutSettingContentType =============================================== Default test Tests run: 1, Failures: 0, Skips: 0
=============================================== ===============================================
Default suite
Total tests run: 1, Passes: 1, Failures: 0, Skips: 0
===============================================
In the above approach, if you misspell the header name and its expected values then you will get an unexpected response. So to overcome that RequestSpecification class provided a below method:-
RequestSpecification contentType(ContentType contentType);
ContentType is an enum which contains members as “ANY”, “JSON”, “XML” etc. If I want to set Content -Type as JSON then I will use contentType() method as below:-
contentType(ContentType.JSON)
A complete example is as below:-
package RestAssuredBasicConcepts;
import org.testng.annotations.Test;
import io.restassured.RestAssured;
import io.restassured.http.ContentType;
public class SetContentTypeForRequest {
@Test
public void settingContentTypeAsContentType()
{
RestAssured
.given()
.log()
.all()
.contentType(ContentType.JSON)
.body("{\r\n" +
" \"firstname\" : \"Jim\",\r\n" +
" \"lastname\" : \"Brown\",\r\n" +
" \"totalprice\" : 111,\r\n" +
" \"depositpaid\" : true,\r\n" +
" \"bookingdates\" : {\r\n" +
" \"checkin\" : \"2018-01-01\",\r\n" +
" \"checkout\" : \"2019-01-01\"\r\n" +
" },\r\n" +
" \"additionalneeds\" : \"Breakfast\"\r\n" +
"}")
.post("https://restful-booker.herokuapp.com/booking")
.then()
.log()
.all();
}
}
Output
[RemoteTestNG] detected TestNG version 7.0.1
Request method: POST
Request URI: https://restful-booker.herokuapp.com/booking
Proxy:
Request params:
Query params:
Form params:
Path params:
Headers: Accept=*/* Content-Type=application/json; charset=UTF-8
Cookies:
Multiparts:
Body:
{ "firstname": "Jim", "lastname": "Brown", "totalprice": 111, "depositpaid": true, "bookingdates": { "checkin": "2018-01-01", "checkout": "2019-01-01" }, "additionalneeds": "Breakfast"
}
HTTP/1.1 200 OK
Server: Cowboy
Connection: keep-alive
X-Powered-By: Express
Content-Type: application/json; charset=utf-8
Content-Length: 195
Etag: W/"c3-Hgn0HOW7t3wbXoNXHOll0aSCOGo"
Date: Tue, 29 Sep 2020 07:58:29 GMT
Via: 1.1 vegur { "bookingid": 12, "booking": { "firstname": "Jim", "lastname": "Brown", "totalprice": 111, "depositpaid": true, "bookingdates": { "checkin": "2018-01-01", "checkout": "2019-01-01" }, "additionalneeds": "Breakfast" }
}
PASSED: settingContentTypeAsContentType =============================================== Default test Tests run: 1, Failures: 0, Skips: 0
=============================================== ===============================================
Default suite
Total tests run: 1, Passes: 1, Failures: 0, Skips: 0
===============================================
You can download/clone the above sample project from here.
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