To allow requests against a Spring Boot REST API from a website it is necessary to configure CORS properly. In case you don’t know your client URLs you can allow all clients by adding a mapping like the following in your Kotlin project: This allows access to all endpoints from all origins via GET, POST […]
CORS configuration for REST api accessed from browser Read More »
I’m using PostgreSQL in a lot of projects and in my dev environments I always run it with docker-compose. But configuring it properly isn’t so clear if you want to use proper time zone and a health check. Attached the config with a custom database name “db” and an admin user. With this pg_isready is
Start PostgreSQL correctly with docker-compose.yml Read More »
My intellij 2023.2 continued to repeatedly index something and it was obvious that it was the same again and again. The typical suggestions to invalidate caches plus restart didn’t work. Then I found the suggestion to edit the custom properties file via Help > Edit Custom Properties and add the following: Taken from https://www.jetbrains.com/help/objc/configuring-file-size-limit.html this
Intellij stuck with indexing Read More »
I found lots of samples for creating a redis testcontainer in Spring Boot tests. But none of them really worked. Below is a working base class with a sample. It is based on Spring Boot 3.1.2 and latest testcontainer version at time of writing (“org.testcontainers:testcontainers:1.18.3”). The testcontainer-redis versions were avoided on purpose because they were
Redis Testcontainer with Kotlin and Spring Boot Read More »
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
Using Generic Spring Boot Events Read More »
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.
OAuth2 client with Spring Boot 3 Read More »
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
Spring Boot WebClient with request logging Read More »
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:
duplicate but no duplicate handling strategy has been set – gradle DuplicationStrategy Read More »
Following the documentation using arkade was (as stated in the docs) the fastest and easiest way to get a working local installation running. There are numerous outdated tutorials about how to run OpenFaaS locally but none of really worked in my envrionment. I am using a MacBook M1 Max with docker driver. I have docker
Local OpenFaaS environment with minikube and docker driver Read More »
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 »