Yuri Mednikov

Tag: Java

Some thoughts on server side validation with Vertx and a bit of Vavr

Eclipse Vertx is a robust technology to build reactive microservices or serverless functions. When you develop such applications, the role of server side validation rises. In traditional web applications we combine both client-side…

How to check if a list contains a value in Clojure

Recently I started to learn Clojure, and usually, my first phase is to complete small programming exercises. To practice Clojure I decided to solve some CodingBat problems. A common task here is to…

Exception handling in Clojure

In some form or another, but exceptions exist in almost any languages. Due to the fact, that Clojure actually runs on JVM, it inherits its exception system from Java. From a technical point…

Home made JWT authentication for Javalin

An authentication with tokens became a must-have feature for modern web apps. It suits natively to single page applications and mobile applications. While Spring is de facto standard in Java ecosystem, there are…

Understand Java Collections

When we talk about Java collections, we consider two things. First, more wide concept, means implementations of common data structures. An another, narrow understanding, corresponds to concrete interfaces and their implementations, that are…

Secure Webflux API endpoints with HandlerFilterFunction

In the previous post we have already talked about authentication in Spring Webflux. We implemented a component, that contains a required business logic to process login and signup, and to issue JWT. However,…

Simple email notification microservice using Vertx

Almost any more or less complex application has to deliver notifications. As usual, it is done via traditional emails, especially in cases of password reset messages or transactional notifications etc. There is a…

Testing Spring reactive services

Unit tests serve to verify individual components, mostly on business logic level, and to ensure that components perform as expected. In Spring Webflux apps this level is a level of services. Here we…

Error handling in Spring Webflux

The topic of error handling in web applications is very important. From a client perspective it is essential to know on how was the request proceeded and in case of any error is…

Two-factor authentication for Spring Webflux APIs

Multi-factor authentication became a common practice for many cases, especially for enterprise ones, or those that deal with sensitive data (like finance apps). Moreover, MFA is enforced (especially in the EU) by law…