[FIXED] How to delete a cookie from backend upon an error

Issue

Currently setting up http only cookie in a Spring boot project via configurations as follows.
This cookie is getting set correctly when ever I call following endpoint.

  @Bean
  public CookieSerializer cookieSerializer() {
    DefaultCookieSerializer serializer = new DefaultCookieSerializer();
    serializer.setDomainNamePattern(".*");
    serializer.setCookieName("my_cookie");
    serializer.setCookieMaxAge(60 * 10); // 10 mins
    serializer.setUseSecureCookie(true);
    serializer.setUseHttpOnlyCookie(true);
    return serializer;
  }

As can see, the cookie called my_cookie is being set for 10 mins.
In my controller within same project, I have the following controller method.
In the event I enter the error block, I wish to delete the cookie called my_cookie. How can I do that?

This is the closest question I found for this but is not the same case considering I set it via configurations.
https://stackoverflow.com/questions/9821919/delete-cookie-from-a-servlet-response

  @PostMapping(value = "/endpoint")
  public List CustomResponse(
          @RequestBody Request request,
          // this is a session cookie coming from frontend, not related to the cookie I want to delete
          @CookieValue(required = false) String otherCookie
  ) throws Exception {

    CustomResponse response = null;
    if (otherCookie != null) {
        CustomResponse response = // perform some other rest request and get value from there 
    }

    if (response == null) {

        // I want to delete the cookie named `my_cookie` at this stage. 

        throw new CustomException('name');
    }

    return response;
  }

Solution

To delete a cookie, set the Max-Age directive to 0 and unset its value. You must also pass the same other cookie properties you used to set it. Don't set the Max-Age directive value to -1. Otherwise, it will be treated as a session cookie by the browser.

// create a cookie
Cookie cookie = new Cookie("username", null);
cookie.setMaxAge(0);
cookie.setSecure(true);
cookie.setHttpOnly(true);
cookie.setPath("/");

//add cookie to response
response.addCookie(cookie);

For more, refer to the post by Dzone: https://dzone.com/articles/how-to-use-cookies-in-spring-boot

Answered By - Pranay Srivastava