Java – Integrity by Design Through Ensuring Illegal States Are Unrepresentable(javajanitorjim.substack.com)

javajanitorjim.substack.com

Java – Integrity by Design Through Ensuring Illegal States Are Unrepresentable

https://javajanitorjim.substack.com/p/java-janitor-jim-integrity-by-design

1 comments

jimofl6 mesi fa

I wanted a simple pattern for preventing a class from being instantiated in an invalid state, or from mutating into one.

Why? Because it vastly reduces the amount and complexity of reasoning required for use at client call-sites.

Think of it as “integrity by design”, a compliment to the “integrity by default” effort undertaken by the Java architects, detailed here.

This article discusses the design and implementation of a record pattern, very similar to the one I designed and implemented for Scala’s case class several years ago, which provides the “integrity by design” guarantees by ensuring that only valid record instances can be observed.

This pattern is also trivially cross-applicable to Java classes.