RestAssured testing, get user token - spring

Question

What I want to do: I want to test my endpoint using RestAssured. The key is that the endpoint is available only for users who are logged in. For logging in I'm using spring security default endpoint with custom successHandler in which I'm setting some random token, saving it to database and returning in header "User-Token". I'm not creating a session on the back end. When I want to access a secured endpoint, front-end makes a call to it, with "User-Token" header. Then I'm using the token for checking in the database. Each token is different and random. Also I don't use any spring-security things for token. Now I want to test this behavior.
Technologies: React & Redux, Spring Boot, RestAssured, JUnit, Tomcat
What's not working: First of all, I'm not really sure how to obtain the token. I mean I can force it by hand to database to some test user, but AFAIK it's a bad bad practice. I read the documentation and come across part about auth().form. But below it was mentioned that it's not the best approach as have to made to the server in order to retrieve the webpage with the login details and it's not possible - webpage is totally separated from backend. I did try the approach nevertheless but it didn't work.
#Before
public void LogInUser(){
String loginUrl = "http://localhost:8080/login";
userToken =
given().auth().form("username","password").
when().get(loginUrl).getHeader("User-Token");
System.out.println(userToken);
}
So then I thought that maybe I don't need auth() at all - I don't need session, so calling the endpoint itself with data should be enough. I checked how data is passed from front-end to back-end and did this:
Form Data: username=something&password=something
#Before
public void LogInUser(){
String loginUrl = "http://localhost:8080/login";
userToken =
given().parameter("username=oliwka&password=jakies")
.when().get(loginUrl).getHeader("User-Token");
System.out.println(userToken);
}
And while it's passing, userToken is null. It's declared as class variable not method variable and it's String.
How can I obtain token for user and test my endpoint for which I need a token?

Answer 1

You can use below procedure to get the access token.
Step 1 : Create a method that will accept a json string and parse the data and return the access token. below is the method. You can use your preferable json parser library.
public String getAccessToken(String jsonStr) {
JSONParser parser = new JSONParser();
Object obj = null;
try {
obj = parser.parse(jsonStr);
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
JSONObject jsonObject = (JSONObject) obj;
String accessToken = (String) jsonObject.get("access_token");
System.out.println("access_token : " + accessToken);
return accessToken;
}
Step 2 : Now call your login api with username and password like below
String loginUrl = "http://localhost:8080/login";
Response res = null;
String returnValue = "";
response = given().param("username", "yourUserName")
.param("password", "yourpassword")
.param("client_id", "If Any otherwise skip it")
.param("grant_type", "If Any otherwise skip it")
.param("clear_all", "true")
.post(loginUrl);
returnValue = response.body().asString();
String accessToken = getAccessToken(returnValue);
Please let me know if you can get your desired access token.