In this article I will, using a test-case, show how to publish and consume MQTT messages using the reactive HiveMQ client library. I will use the Mosquitto MQTT broker for the test. The example application will be implemented using Spring Boot 3 and Java 17. The example will initially allow unauthenticated access that later will… Read More »
In this article I will show how to reduce the set of application configuration properties available to a Spring Boot test. The reason for me wanting to do this is to be able to write tests for code that relies on a dynamic set of configuration properties. The source-code of the completed example project can… Read More »
In this article I will use Prometheus and Alertmanager to send alarms when disk-space is low for a Spring Boot application. Actually, any service or application which have metrics that can be scraped by Prometheus can have alarms so the technique described in this article is not only applicable to Spring Boot services and applications.… Read More »
In this article I will show how I added disk-space metrics to the set of default metrics made available for scraping by Prometheus. There are a few ways to accomplish this but I have chosen to use data from the Spring Boot Actuator health data. A complete Spring Boot application with disk-space metrics is available… Read More »
The following are a few words and some simple examples showing how to use Spring Data DynamoDB to store and retrieve data in a DynamoDB database. In the example, which consists of a few tests, I will use a local instance of DynamoDB running in a container. No prior knowledge of DynamoDB is assumed, though… Read More »
Due to problems with PayPal, I have decided to move the sales of my book Core Spring 5 Certification in Detail to Kobo. Many thanks to LeanPub for the time that has been – they have been very friendly and helpful!
For quite some time now I have thought it would be very useful to have some type of id associated with the processing of a request logged in connection to the log messages generated when the request is processed. This in order to be able to query Elasticsearch or similar for all the logs generated… Read More »
In this article I will show how to prepare message payloads with parameters in different formats using the Thymeleaf template engine. No previous knowledge of Thymeleaf is assumed. As far as I am concerned there are several use cases for this. Some examples are: System integration. Requests can be maintained as plain files and no… Read More »
A short note to tell you that my REST example application has been updated for the first release candidate of Spring 5 as well as the first milestone for Spring Boot. Some minor changes in the API I’ve used, such as introducing findById in Spring Data JPA repositories which return an Optional. I’ve also created… Read More »
Now ladies and gentlemen! It is time for a debugging break in the series of articles about the REST service! Actually, this article is related to the REST service – it will describe a problem with the classpath-scanning of Jersey that manifest itself in standalone Spring Boot applications with a so-called fat JAR. I will also… Read More »