本部分提供了概述，关于RESTful服务在GeoServer中是如何工作的。
https://docs.geoserver.org/stable/en/developer/programming-guide/rest-services/index.html
第一章：Overview概述
GeoServer uses a library known as Restlet for all REST related functionality. Restlet is a lightweight rest framework written in Java that integrates nicely with existing servlet based applications.
GeoServer使用一个类库叫做Restlet来处理所有的REST相关的功能。Restlet是一个轻量级的REST框架，以Java语言写的，与现有的Servlet程序能够完美的融合。
REST dispatching
In GeoServer, all requests under the path /rest are considered a call to a restful service. Every call of this nature is handled by a rest dispatcher. The job of the dispatcher is to route the request to the appropriate end point. This end point is known as a restlet.
Restlets are loaded from the spring context, and therefore are pluggable.
Restlets
A restlet is the generic entity which handles calls routed by the dispatcher, and corresponds to the class org.restlet.Restlet. One can extend this class directly to implement a service endpoint. Alternatively one can extend a subclass for a specialized purpose. Namely a finder, which is described in the next section.
Finders and resources¶
Restful services are often implemented around the concept of resources. A finder is a special kind of restlet whose job is to find the correct resource for a particular request. The resource then serves as the final end point and handles the request. The appropriate classes from the restlet library are org.restlet.Finder and org.restlet.resource.Resource.
Representations
A representation, commonly referred to as a format, is the state of a particular state or encoding of a resource. For instance, when a request for a particular resource comes in, a representation of that resource is returned to the client.
最新的GeoServer是使用SpringMVC来实现的REST服务，抛弃了Restlet。。：https://blog.csdn.net/nmj2008/article/details/116997868 从GeoServer2.12版（2017）开始采用的SpringMVC，但是开发文档没有更新
新旧REST对比：
左边为原来实现REST的方式，很简单就实现了一个REST服务。但是，新的例子不能用
应该换成哪些类呢？
调试：发现从DispatcherServlet->RestInterceptor->RequestInfo
