The OpenEdge Hive

In recent years, there has been a dramatic rise in the popularity of the concept of an Enterprise Service Bus (ESB) over a Service-Oriented Architecture (SOA). This popularity has been especially notable in the context of Enterprise Application Integration (EAI) and related domains where the requirement is for multiple applications to interact, often from multiple companies and distributed across multiple computers. Sonic Software has been one of the most notable evangelists of this concept and arguably provides the best overall infrastructure for implementing this approach.

A use case prepared for Progress Software to document the need for a multi-threaded client.

One of the problems faced by ABL programmers for many years is the lack of a true exception handling mechanism in the language. By “exception handling”, we mean a mechanism by which a program encounters an error or unexpected condition then can communicate up the call stack with the purpose of:
1. Signaling that requested execution has not completed as expected;
2. Communicating any necessary information about the details of why this condition occurred; and
3. Providing a structure such that the condition is “handled” in a graceful fashion at an appropriate level in the code.

In developing a foundation framework for Object-Oriented ABL, it seems natural to consider creating a set of Collection classes since they have a broad utility in OO design in other languages. It also seems natural to consider imitating the Collection classes in Java since that is a tried and true implementation into which there has been a considerable investment of thought and effort.