‘Advanced OO Design’ series

Real software sees entities (Customer, File etc) involved in multiple interactions. Simple OO examples model behavior in entity classes directly, but this becomes tangled as behaviors & interactions increase; and results in broken inheritance structures.

Instead of modelling these all in the entity, a more advanced OO approach considers separating behavior from the entity. We’ll consider key principles in this multi-part series. Continue reading

Value Types & List<int> coming for Java 10 ?

Oracle, with lead engineer Brian Goetz, have launched an experimental OpenJDK project to bring long-awaited features to the Java platform.

Major enhancements to generics & new ‘value types’ are planned. Highlights include:

  • Value Types;  highly-efficient small ‘objects’ without inheritance.
  • Reified Generics;  retaining their actual type at runtime.
  • Generic Specialization;  List<int> would be valid & highly efficient.
  • ‘volatile’ enhancements.

The effort is named Project Valhalla. Here’s a preview: Continue reading

Explicit vs Implicit configuration in Spring

With the move to annotations for use of Spring, many projects have become based on component-scanning, auto-wiring and property-placeholder injection — an ‘implicit’ approach to configuration.

However, it can still be very useful to specify ‘explicit’ configuration. This gives us control of top-level application config & enables extensible configuration using the Strategy pattern.

Gaining control of configuration is crucial to enable per-customer/ per-application customization. Continue reading