Hot deploying a context

The reloadable attribute of a context indicates that resources should be watched for modification and that a reload of the context should be triggered if an application's resources have been modified.

Note

While reloading a context is invaluable during development, it requires significant runtime overhead and so should be left turned off in a production environment.

Determining if a reload is necessary

As we saw in the last chapter, a context may be reloaded when a watched resource is modified or deleted. In addition, a key responsibility of a WebappLoader is to provide a backgroundProcess() method implementation that is called by its parent container's background processing thread. Note that this method is of use only for a context whose reloadable attribute is set to true.

This method delegates to its WebappClassLoader instance, which checks each class or resource name in the paths array to see whether it has been modified since it was last accessed, by comparing its...