Relationship between uniform, restlet, and sub-classes -- restlet 2.2

Uniform is the top-level interface of the restlet WebService framework. Only one public void handle (request, response) method is declared.

Restlet implements the uniform interface, but does not overwrite the handle (request, response) method in the uniform, so restlet is an abstract class.

In this way, a rule is generated:

1. All restlet subclasses must implement the handle (request, response) method in the uniform;

2. When all restlet subclasses implement the handle (request, response) method, they must first call the handle (request, response) method in restlet.