Using Spring Events can be very handy to decouple code. But have you ever tried creating generic events and then write a listener for them? Java or Kotlin themselves don’t prevent you from doing so but when you try receiving the events you will see that it doesn’t work. The reason for this is type …
With Spring Boot 3 some classes were deprecated and also the Keycloak adapter and the admin client stopped working in an application I am maintaining. In https://blog.coffeebeans.at/archives/1904 I already showed how to instantiate a WebClient which is the new way Spring wants us to call external APIs – not considering external libs like feign now. …
RestTemplate is dead and everybody should use WebClient now. That’s what you find everywhere so I had a look how to configure an instance of WebClient properly: This defines a bean genericWebClient with Spring Boot configured Jackson ObjectMapper instance. Here is also the code for the WebClientLoggerBuilder: This simply logs method, path and headers of …
While using Java and Kotlin with Spring Boot the following exception occurs and it’s quite hard to find how to fix it. The simple solution is to add the following top level config in your gradle file:
When upgrading to the latest tools and libraries in a Spring Boot application with OpenAPI code generator in place the OpenAPI Kotlin generator introduced jakarta.annotation:jakarta.annotation-api. But with this in place the application refused to start with something like org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat…Caused by: java.lang.IllegalStateException: …
java.lang.ClassNotFoundException: javax.annotation.PostConstruct Read More »
Project lombok has become a defacto standard in close to every Java project I see. Because of this I want to also write about the ongoing log4j problems as described under https://blog.coffeebeans.at/archives/1709. The annotation @Log4j allows to create a log4j logger field in the annotated class. This of course implicates that your project is using …
I’ve started to write a simple plugin to analyse gradle projects and send dependency information to a central server. This way I want to get insight into all projects in the company and check if there is some log4j2 dependency below 2.16.0. You can find the code under https://github.com/mbogner/gradle-status-plugin. The plugin was accepted and is …
I was looking for a way to validate JSON data structure with the schema saved in the database. PostgreSQL has a very cool way to store json in JSONB fields but the question was how to validate this without extra PostgreSQL plugins and integrated in hibernate’s lifecycle with bean validation. Under https://github.com/mbogner/schema-validator I came up …
JSON in PostgreSQL with application side validation Read More »
Sometimes, especially during debugging, it would be helpful to mark single lines in the log in colours. There is a simple way to achieve this with Spring Boot and logback. With this dependency in place you can extend your logger to achieve this. Here a sample setup: This allows you to mark a resource in …
Spring Boot contains a quite nice configuration for logback with color coding and good readability. But it lacks logging MDC (Mapped Diagnostic Context) content. I tried around and found a way to append MDC to every logged line by setting the console pattern in my application.properties/yml under logging.pattern.console to Without any MDC set this adds …