Validation for Spring Webflux APIs with Yavi

In Spring MVC a server-side validation was implemented using annotations. We could just put @Valid before the body payload in the controller method and Spring did all dirty work for us. On the other side, Spring Webflux implements a functional-style web layer, which is based on router functions and handlers. This is non-blocking API and […]

Read More

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 and server-side validation techniques. However, in API world we can be in situations without clients (when you have a public API). We […]

Read More

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 check, if an array does contain some value. The expected result should be a boolean value. When I moved to practical implementations, […]

Read More

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 developers, who prefer to use alternative solutions. This is true, because Spring is quite heavy platform and there is a number of […]

Read More

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, to fullfil this security flow, we also need a component, that we assert a token: extract Authorization header from HTTP request and […]

Read More

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 number of cloud solutions that abstract mail flow via consumable REST API. For example, Postmark. I used Postmark for some time, but […]

Read More

You don’t need Hibernate with Spring Webflux and R2DBC

One of issues when you work with relational databases in Java is that they are unable to translate object relationships (such as composition) due to the tabular nature of data sources. That means that as developers we usually tend to have an intermediate layer, which is responsible to abstract the data source’s data organization. This […]

Read More