Heath Casey's Blog

Jakarta (Java) EE 8 Observer Example

CDI 2.0 Observer The observer pattern is very when you want to perform actions based on events that are being fired in your application. To implement the pattern with CDI in the Jakarta EE 8 api you will need to add the following pieces: Event Trigger Listener Event The javax.enterprise.event.Event is what you will need…

InJava Programming

Java EE Design Patterns

Classification and Scope Summary The original Gang of Four Design Patterns can be categorized by their scope (compile-time or run-time) and by their purpose. Creational patterns are for creation and initialization. Structural patterns define relations between classes and objects. Behavioral patterns control communications and interactions. Creational Structural Behavioral Class Scope (Compile-time) -Factory Method -Adapter* -Interpreter-Template…

InDatabases SQL

Common Task performed on Data with SQL Queries

Some useful Snippets While working with multiple database vendors, slight differences in syntax can cause the query to return unexpected results. For my own quick reference, reference I have decided to jot down a few select statements that perform some common task well in MySQL. The tables used for the examples can be created with…