How to send GET Request in Rest Assured

@Test
    public void getMethodWithoutBDDApproach() {
        RequestSpecification request = RestAssured.given();
        request.baseUri("http://localhost:8088");

        Response response = request.get("/employees");

        // Let's print response body.
        String responseString = response.asString();
        System.out.println("Response Details : " + responseString);

        /*
         * To perform validation on response like status code or value, we need to get
         * ValidatableResponse type of response using then() method of Response
         * interface. ValidatableResponse is also an interface.
         */
        ValidatableResponse validatableResponse = response.then();
        // It will check if status code is 200
        validatableResponse.statusCode(200);
        // It will check if status line is as expected
        validatableResponse.header("Content-Type", "application/json;charset=UTF-8");
        validatableResponse.body("[0].id", Matchers.equalTo(1));
        validatableResponse.body("[0].firstName", Matchers.equalTo("saurabh"));
        validatableResponse.body("[0].lastName", Matchers.equalTo("oza"));
        validatableResponse.body("[0].salary", Matchers.equalTo(1000));
        validatableResponse.body("[0].email", Matchers.equalTo("saurabh@abc.com"));
    }

Let’s start with some basic points about Rest Assured:-

RestAssured is a class which consists many static fields and methods.
It supports POST, GET, PUT, DELETE, HEAD, PATCH and OPTIONS requests and to verify the response of these requests.

1. Set URI
First we need to set the base uri of our api. uri is the base url without the resource. means in our case the complete url is http://localhost:8088/employees and here the uri is http://localhost:8088/ and the resource name is employees.

RequestSpecification request = RestAssured.given();
request.baseUri("http://localhost:8088/");

2. Call get method
RestAssured has a static overloaded method named get(String resourceName) which returns a reference of Response interface. In fact return type of all http methods in RestAssured class is of type Response. This response contains every details returned by hitting request i.e. response body, response headers, status code, status lines, cookies etc. Here we have captured the response and printed on console.

Response response = request.get("/employees");

3. Validate the response
To validate response like status code or value , we need to get reference of type ValidatableResponse. ValidatableResponse is an interface. Response interface has a method named “then()” which returns ValidatableResponse. In fact there is an interface called “Validatable” which has “then()” method. Response interface extends
Once we get ValidatableResponse reference, we can do many assertions. In this post, we will verify status code and status line. It consists of many validation methods.

In below code we are first validating the status code then the value of “Content-Type” header and then we are validating the first record of the employee list and comparing all the properties with expected value. We are using the JsonPath to retrieve the value from the response json. [0] means 0th index of the array and [0].id means id of first element.
Don’t worry about the JsonPath. We will learn about them in our upcoming blog.

body method takes 2 parameters, first is the json path for which the value you have to compare nd second one is the Matcher which has lots of method to compare the value.

T body(String var1, Matcher<?> var2, Object... var3);
 

/*
         * To perform validation on response like status code or value, we need to get
         * ValidatableResponse type of response using then() method of Response
         * interface. ValidatableResponse is also an interface.
         */
        ValidatableResponse validatableResponse = response.then();
        // It will check if status code is 200
        validatableResponse.statusCode(200);
        // It will check if status line is as expected
        validatableResponse.header("Content-Type", "application/json;charset=UTF-8");
        validatableResponse.body("[0].id", Matchers.equalTo(1));
        validatableResponse.body("[0].firstName", Matchers.equalTo("saurabh"));
        validatableResponse.body("[0].lastName", Matchers.equalTo("oza"));
        validatableResponse.body("[0].salary", Matchers.equalTo(1000));
        validatableResponse.body("[0].email", Matchers.equalTo("saurabh@abc.com"));

Rest assured http get request api automation with BDD approach – 
BDD is an agile software development process (Not a Software Testing process) which defines expectation from an application to behave from intended user prospective.
Each scenario is written in form of

• Given (Pre-conditions/ Context), 
• When (Action/Event Performed) and 
• Then (Result/Outcomes) format.

@Test
public void getMethodWithBDDApproach() {
    RestAssured.given() //precondition is to give the base uri
        .baseUri("http://localhost:8088/")
        .when() //actual action is to perform the get request
        .get("employees")
        .then() // will return the ValidatadleResponse from the Response object
        .statusCode(200)
        .body("[0].id", Matchers.equalTo(1))
        .body("[0].firstName", Matchers.equalTo("saurabh"))
        .body("[0].lastName", Matchers.equalTo("oza"))
        .body("[0].salary", Matchers.equalTo(1000))
        .body("[0].email", Matchers.equalTo("saurabh@abc.com"));
}

BDD http get request with specific employee –

@Test
 public void getWithIdMethodWithBDDApproach() {
     String requestEmployeeId = "2";
     RestAssured.given() //precondition is to give the base uri
             .baseUri("http://localhost:8088/")
             .pathParam("employee_id", requestEmployeeId)
             .when() //actual action is to perform the get request
             .get("employees/{employee_id}")
             .then() // will return the ValidatadleResponse from the Response object
             .statusCode(200)
             .header("Content-Type", "application/json;charset=UTF-8")
             .body("id", Matchers.equalTo(2))
             .body("firstName", Matchers.equalTo("only"))
             .body("lastName", Matchers.equalTo("fullstack"))
             .body("salary", Matchers.equalTo(2000))
             .body("email", Matchers.equalTo("onlyfullstack@abc.com"));
 }

Below is the complete program for http get request method with rest assured

package onlyfullstack.httpMethods;

import io.restassured.RestAssured;
import io.restassured.module.jsv.JsonSchemaValidator;
import io.restassured.response.Response;
import io.restassured.response.ValidatableResponse;
import io.restassured.specification.RequestSpecification;
import org.hamcrest.Matchers;
import org.testng.annotations.Test;

public class GetHttpMethodExample {

    @Test
    public void getMethodWithoutBDDApproach() {
        RequestSpecification request = RestAssured.given();
        request.baseUri("http://localhost:8088");

        Response response = request.get("/employees");

        // Let's print response body.
        String responseString = response.asString();
        System.out.println("Response Details : " + responseString);

        /*
         * To perform validation on response like status code or value, we need to get
         * ValidatableResponse type of response using then() method of Response
         * interface. ValidatableResponse is also an interface.
         */
        ValidatableResponse validatableResponse = response.then();
        // It will check if status code is 200
        validatableResponse.statusCode(200);
        // It will check if status line is as expected
        validatableResponse.header("Content-Type", "application/json;charset=UTF-8");
        validatableResponse.body("$", Matchers.hasSize(3));
        validatableResponse.body("[0].id", Matchers.equalTo(1));
        validatableResponse.body("[0].firstName", Matchers.equalTo("saurabh"));
        validatableResponse.body("[0].lastName", Matchers.equalTo("oza"));
        validatableResponse.body("[0].salary", Matchers.equalTo(1000));
        validatableResponse.body("[0].email", Matchers.equalTo("saurabh@abc.com"));
    }

    @Test
    public void getMethodWithBDDApproach() {
        RestAssured.given() //precondition is to give the base uri
                .baseUri("http://localhost:8088/")
                .when() //actual action is to perform the get request
                .get("employees")
                .then() // will return the ValidatadleResponse from the Response object
                .statusCode(200)
                .header("Content-Type", "application/json;charset=UTF-8")
                .body("[0].id", Matchers.equalTo(1))
                .body("[0].firstName", Matchers.equalTo("saurabh"))
                .body("[0].lastName", Matchers.equalTo("oza"))
                .body("[0].salary", Matchers.equalTo(1000))
                .body("[0].email", Matchers.equalTo("saurabh@abc.com"));
    }

    @Test
    public void getWithIdMethodWithBDDApproach() {
        String requestEmployeeId = "2";
        RestAssured.given() //precondition is to give the base uri
                .baseUri("http://localhost:8088/")
                .pathParam("employee_id", requestEmployeeId)
                .when() //actual action is to perform the get request
                .get("employees/{employee_id}")
                .then() // will return the ValidatadleResponse from the Response object
                .statusCode(200)
                .header("Content-Type", "application/json;charset=UTF-8")
                .body("id", Matchers.equalTo(2))
                .body("firstName", Matchers.equalTo("only"))
                .body("lastName", Matchers.equalTo("fullstack"))
                .body("salary", Matchers.equalTo(2000))
                .body("email", Matchers.equalTo("onlyfullstack@abc.com"));
    }
}

Lets go to our next tutorial where we will discuss below points :

Part 4 – How to make a POST Request using Rest Assured

 – What is POST?
 – How to make a POST Request using Rest Assured?
 – Rest assured http post request api automation without BDD approach
– Rest assured get api automation with BDD approach
https://www.onlyfullstack.com/how-to-send-post-request-in-rest-assured/

Source Code
You can find the complete source code on below GitHub repository – 
https://github.com/onlyfullstack/rest-assured-tutorial

Rest Assured Tutorial
https://www.onlyfullstack.com/rest-assured-tutorial-for-beginners/