Hardcore Java

Chapter 9. Practical Reflection

Reflection is one of the least understood aspects of Java, but also one of the most powerful. Reflection is used in almost every major production product on the market, yet it often has to be learned from developers who are already experts, and these developers are often few and far between.

The reason for using reflection is because of the difficulties in building complex projects in a short time. As your projects become more advanced, you may find that you have less time to finish them.

For example, consider the Online Only Bank data model from Chapter 8. It was relatively small and simple to understand. When designing a GUI to manipulate this data model, you may be tempted to fire up a GUI builder tool and start making forms for each of the objects. In the end, you would have as many forms as there are data model objects. In fact, this is how most GUIs are built today.

However, consider if you used the same technique on a data model with over 200 data model objects and thousands of relationships among the items. In this situation, the idea of using the GUI builder tool is much less appealing—you would need to budget months of man-hours to complete the project. Furthermore, whenever any of these objects changes, even slightly, you would need to go back and fix all of the panels of the affected object. The icing on this particularly bitter cake is that you would have to create new panels each time a new object is introduced into the system. Clearly, ...