REST Assured Tutorial 50 – How to set Content-Type for request in Rest Assured

Introduction

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.

Prerequisite

I have used below dependency of Rest Assured library for this post:-



    io.rest-assured
    rest-assured
    4.3.1
    test

Why we may need to set Content-Type explicitly for a request?

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.

Adding Content-Type to a request in Rest Assured

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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1 thought on “REST Assured Tutorial 50 – How to set Content-Type for request in Rest Assured”

  1. I have simple test using rest assured as below.
    Case1: If I pass json string as below, it works fine.

    @Test
    public void dummyTest throws Exception {

    String newUserEmail = “postOrder” + UUID.randomUUID() + “@gmail.com”;
    String json = “{\n” +
    ” \”name\”: \”Marisa\”,\n” +
    ” \”birthday\”: \”1997-10-06\”,\n” +
    ” \”title\”: \”Dr.\”,\n” +
    ” \”email\”: \”postOrder26@gmail.com\”,\n” +
    ” },\n”
    given()
    .baseUri(“my_request_url”)
    .header(“Content-Type”, “application/json”)
    .body(json)
    .when()
    .post()
    .then()
    .log().all();
    }

    Above returns 200 response.
    ***************************************************************************************************
    But If I write my test as below , passing email as variable, returns 500
    @Test
    public void dummyTest throws Exception {

    String newUserEmail = “postOrder” + UUID.randomUUID() + “@gmail.com”;
    String json = “{\n” +
    ” \”name\”: \”Marisa\”,\n” +
    ” \”birthday\”: \”1997-10-06\”,\n” +
    ” \”title\”: \”Dr.\”,\n” +
    ” \”email\”: \””+newUserEmail+”\”,\n” +
    ” },\n”
    given()
    .baseUri(“my_request_url”)
    .header(“Content-Type”, “application/json”)
    .body(json)
    .when()
    .post()
    .then()
    .log().all();
    }

    **********************************************************************************************************************************

    I get 500 error response

    HTTP/1.1 500 Internal Server Error
    Content-Type: text/html; charset=UTF-8
    Transfer-Encoding: chunked
    Connection: keep-alive
    Date: Mon, 16 Aug 2021 17:05:36 GMT
    Server: Apache
    Cache-Control: no-cache, private
    X-Cache: Error from cloudfront
    Via: 1.1 871dedfc10f4428aa2412b6f788b791a.cloudfront.net (CloudFront)
    X-Amz-Cf-Pop: ZRH50-C1
    X-Amz-Cf-Id: xGkO8cJGV0Pq7wAx71YyglWzQNdZzooohqZLZBHkC54iZgiNhGmpEA==

    /* Copyright (c) 2010, Yahoo! Inc. All rights reserved. Code licensed under the BSD License: https://yuilibrary.com/license/ */
    html{color:#000;background:#FFF;}body,div,dl,dt,dd,ul,ol,li,h1,h2,h3,h4,h5,h6,pre,code,form,fieldset,legend,input,textarea,p,blockquote,th,td{margin:0;padding:0;}table{border-collapse:collapse;border-spacing:0;}fieldset,img{border:0;}address,caption,cite,code,dfn,em,strong,th,var{font-style:normal;font-weight:normal;}li{list-style:none;}caption,th{text-align:left;}h1,h2,h3,h4,h5,h6{font-size:100%;font-weight:normal;}q:before,q:after{content:”;}abbr,acronym{border:0;font-variant:normal;}sup{vertical-align:text-top;}sub{vertical-align:text-bottom;}input,textarea,select{font-family:inherit;font-size:inherit;font-weight:inherit;}input,textarea,select{*font-size:100%;}legend{color:#000;}
    html { background: #eee; padding: 10px }
    img { border: 0; }
    #sf-resetcontent { width:970px; margin:0 auto; }
    body { background-color: #fff; color: #222; font: 16px/1.5 -apple-system, BlinkMacSystemFont, “Segoe UI”, Roboto, “Helvetica Neue”, Arial, sans-serif; margin: 0; }
    .container { margin: 30px; max-width: 600px; }
    h1 { color: #dc3545; font-size: 24px; }

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