my blog. for you.

Let’s talk digital.

I’m an independent IT consultant and entrepreneur in the Internet and software business. I’m interested in design, enterprise applications, web apps and SaaS products. I design and develop business solutions and applications. I help companies in terms of software quality and knowledge transfer, e.g. with Angular and Spring Boot.

Better Error Handling for Your Spring Boot REST APIs: Error Handling Spring Boot Starter by Wim Deblauwe

Robust and consistent error handling is key when working with any kind of software framework. While Spring itself generally is doing a pretty decent job at that, when it comes to providing REST APIs with Spring Boot the framework is rather lacking. To provide a more consistent error handling experience with Spring Boot REST APIs, Wim Deblauwe (of Taming Thymeleaf fame has release an Error Handling Spring Boot Starter, which enforces robust error handling across a Spring Boot application. See his article on ...

REST next level: Crafting domain-driven web APIs by Julien Topçu @ Spring I/O 2023

Sunday December 3rd, 2023 by Bjoern in Enterprise Software, Software, Web Applications

Action Jackson! Effective JSON processing in Spring Boot Applications by Joris Kuipers @ Spring I/O 2023

Sunday August 6th, 2023 by Bjoern in Enterprise Software, Software

JSON Visualization With JSON Crack

JSON Crack is a JSON visualization solution that allows to generated ad-hoc graph visualizations for your JSON data. While one of the huge advantages of JSON over other data formats certainly is that it's human-readable, more complex JSON documents containing linked data structures can become unwieldy and difficult to understand - at a cursory glimpse, at least. Such situations is where a tool like JSON Crack for visualizing data can come handy.

Saturday April 1st, 2023 by Bjoern in Software, Web Applications

Problem Spring Web: A Library for Handling Problems in Spring Web MVC

Problem Spring Web is an implementation of the proposed application/problem+json HTTP API problem details response for Spring Web (im both its MVC and WebFlux flavours). Error responses should be a first-class citizen when it comes to providing REST APIs. These responses often are generated in an ad-hoc, non-standardised fashion, which not only makes handling such responses more difficult and tedious in client applications but also makes for less maintainable software in the back-end software providing the API. Problem Spring Web attempts to ...

Sunday October 23rd, 2022 by Bjoern in Enterprise Software, Software, Web Applications

Documenting REST APIs Provided by Express Applications

swagger-jsdoc is an NPM library that allows us to generate an OpenAPI specification for REST APIs provided by an Express application. swagger-jsdoc consumes YAML-formatted OpenAPI specification segments within JSDoc comments annotated with the @openapi annotation and turns those into a comprehensive OpenAPI specification for our API. This specification, in turn, can for example be used for automatically having a Swagger UI documentation page created for our REST APIs (using Swagger UI Express, for instance). While annotating Express routes with syntactically and semantically correct OpenAPI ...

Sunday March 13th, 2022 by Bjoern in Software, Web Applications

CORS: What It Is and How It Works

Expanding on last week's article on best practices for REST API Design I'd like to point to a specific aspect working REST APIs frequently entails: A browser security feature called "Cross-Origin Resource Sharing (CORS)". This feature allows you to define which resources provided by a web application are supposed to be accessible from which origin, which in turn typically is comprised of protocol, host / domain name and port. This website's origin for example is https://bjoernkw.com:80 (port 80 is the default port ...

Sunday May 2nd, 2021 by Bjoern in Front End Development, Software, Web Applications

REST API Design: Best Practices

It's probably safe to say that REST (REpresentational State Transfer - originally described by Roy Fielding) is the most widely used architectural pattern when it comes to APIs in web application contexts. From statelessness, to self-descriptive messages, and hypermedia as the engine of application state (HATEOAS) REST comes with quite a few principles, constraints, patterns, and flavours, not all of which are used or applied consistently with each REST API. REST often is a rather loosely-applied architectural pattern or a continuum, on ...

Sunday April 25th, 2021 by Bjoern in Software, Web Applications

The Richardson Maturity Model for REST APIs

On his website about software design patterns Martin Fowler provides an in-depth explanation of the Richardson Maturity Model for HTTP-based REST APIs by Leonard Richardson. According to that model REST APIs come in 4 levels of sophistication: Level 0, aka the "Everything is a POST request" model for example propagated by SOAP. This is basically tantamount to remote procedure invocation. Level 1 - Resources: Every resource is accessed through its own canonical URL. Level 2 - HTTP Verbs: Verbs such as GET, PUT, PATCH and ...

Sunday March 15th, 2020 by Bjoern in Software, Web Applications

JSON Web Tokens: Downsides, Best Practices and Secure and Robust Alternatives

JSON Web Tokens (JWTs) nowadays are commonly used for transmitting authentication data in web applications, especially those exhibiting the widespread client-server architecture where you have a fat client / single-page application written in JavaScript as a front-end and a back-end server providing REST endpoints for use by that front-end client. However, while common there are good arguments against this practice. In a nutshell, JWT often are used for storing session data such user authorization and authentication information although they aren't particularly well-suited to ...

Sunday November 10th, 2019 by Bjoern in Enterprise Software, Front End Development, Software, Web Applications

Björn Wilmsmann

my blog. for you.

Let’s talk digital.