All posts by Dan Newton

I am a Computer Science graduate from the University of Leicester and currently working at Accenture as a Java Developer. Opinions and views found in my posts are my own and do not represent Accenture's views on any subject.

Removing elements from a Map in Java

Very short and simple post on removing elements from a Map in Java. We will be focusing on removing multiple elements and ignore the fact you can remove a single element using Map.remove. The Map below will be used for this post: There are a few ways to remove elements. You could loop through the ...

Extending and Overriding Flows from external CorDapps

Corda 4 was released last week (21st Feb) bringing with it a ton of new features to make Corda more enjoyable to work with. To be honest, I am kind of assuming there are a lot of new features. I had a quick browse through the changelog, mainly to see my contributions being referenced, but ...

Asynchronous RDBMS access with Spring Data R2DBC

Not too long ago, a reactive variant of the JDBC driver was released. Known as R2DBC. It allows data to be streamed asynchronously to any endpoints that have subscribed to it. Using a reactive driver like R2DBC together with Spring WebFlux allows you to write a full application that handles receiving and sending of data ...

Testing exceptions in Kotlin with assertFailsWith

I wanted to write this short post to highlight the assertFailsWith function available to Kotlin that makes testing exceptions a bit easier. Testing exceptions isn't something fancy or new to JVM languages (from now on I will use Java for comparisons) but Kotlin comes with the nice extra benefit of providing this functionality as part ...

Configuring Logback with Spring Boot

Logback is provided out of the box with Spring Boot when you use one of the Spring Boot starter dependencies as they include spring-boot-starter-logging providing logging without any configuration and can be altered to work differently if required. There are two ways of providing your own configuration, if you only need simpler alterations they can ...

https://pixabay.com/en/chainlink-fence-metal-wire-690503/

Privately scoped variable in a `when` block

Super short post, on a change introduced in Kotlin 1.3 (yes I know it has been out for a while now). We will take a quick look at capturing the subject of a when block into a scoped variable. This is a quality of life improvement that saves a line or so of code while ...

https://pixabay.com/en/sydney-opera-house-opera-house-3381786/

Validating external data with an Oracle

I hang out in the Corda Slack channel quite a lot and try to answer questions when I can. A reasonable number of questions I have attempted to answer are related to Oracles. More specifically, when to use one. I feel like I can answer that, "Use an Oracle when you need to validate external ...