java - 什么是 JAX-RS 资源？

Question

我经常听到提到 JAX-RS 的“资源”这个词，但我不知道它是什么意思。我知道什么是 JAX-RS Web 服务。我经常创建它们，但我发现“资源”这个词非常含糊。 JAX-RS 是或可以是很多东西，所以每次我听到世界“资源”时，我的大脑都会将其解释为“神奇的神秘事物，我们不知道是什么”。用最明确的术语来说，什么是 JAX-RS 资源？是客户端吗？服务器？任何一个？还有别的东西在一起吗？资源这个词似乎到处都是，但我几乎找不到代码中 Resource 类型的 Java 对象。然后是 Spring 和 ORM 映射注释..

如果我是 911 接线员，而您在发生可怕事故后调用我让自己恢复原状，我可能会向您发送“医疗资源”。那是一个叫乔的机械师，他从护理人员学校辍学并正在骑自行车，还是救护车上的真正护理人员？ ;-)

乔正在为手术做准备。有什么遗言吗？？ ;-)

Answer 1

JAX-RS 资源类(参见下面的“根资源类”)用于表示 RESTful 资源。引用资料:

1. Chapter 3 Resources

   Using JAX-RS a Web resource is implemented as a resource class and requests are handled by resource methods. This chapter describes resource classes and resource methods in detail.

   3.1 Resource Classes

   A resource class is a Java class that uses JAX-RS annotations to implement a corresponding Web resource. Resource classes are POJOs that have at least one method annotated with @Path or a request method designator.

   — JSR 339: JAX-RS 2.0: The Java API for RESTful Web Services, Version 2.0 Final Release, page 11.

2. Root resource classes are "plain old Java objects" (POJOs) that are either annotated with @Path or have at least one method annotated with @Path or a request method designator, such as @GET, @PUT, @POST, or @DELETE. Resource methods are methods of a resource class annotated with a request method designator. This section explains how to use JAX-RS to annotate Java classes to create RESTful web services.

   — 29.2 Creating a RESTful Root Resource Class - Java Platform, Enterprise Edition: The Java EE Tutorial (Release 7).

RESTful 资源:

5.2.1.1 Resources and Resource Identifiers

The key abstraction of information in REST is a resource. Any information that can be named can be a resource: a document or image, a temporal service (e.g. "today's weather in Los Angeles"), a collection of other resources, a non-virtual object (e.g. a person), and so on. In other words, any concept that might be the target of an author's hypertext reference must fit within the definition of a resource. A resource is a conceptual mapping to a set of entities, not the entity that corresponds to the mapping at any particular point in time.

— Fielding Dissertation: CHAPTER 5: Representational State Transfer (REST).