Re-read configuration without restart

Question

Suppose I've got a Java application, which uses properties files as its configuration. Now I'd like to make the application re-read the configuration without restart. I'll call such configuration "refreshable".

What is the easiest way to do that?

Suppose I am developing an application from scratch. How should I design it to make its configuration "refreshable"?

Answer 1

Using the commons-configuration is probably the easiest way to go. Here is an example of usage. There are many other features included, like hierarchical configuration (with overriding by defaults), JDBC sources, etc.