• Web Service - RESTful
  • What is RESTful
  • REST v.s. SOAP
    • Differences between SOAP WS and RESTful WS
    • When to use REST?
    • When to use SOAP?
  • Server Response Format
  • Example
    • JAX-RS with Jersey
    • REST with Spring
    • Other Spring-REST Peojects
  • Testing Tools
  • Links

Web Service - RESTful

What is RESTful

Representational State Transfer （表现层状态转化）

an architecture design that define a stateless client where web services are treated like resources and can be accessed and identified by URL

RESTful架构，是目前流行的一种互联网软件架构

• 每一个URI代表一种资源
• 客户端和服务器之间(Client-Server架构)，传递这种资源的某种表现层
• 客户端通过四个HTTP动词，对服务器端资源进行操作，实现”表现层状态转化”

组合起来就是，基于Client-Server架构，使用HTTP动词，对资源进行操作/传递。

http://www.ruanyifeng.com/blog/2011/09/restful.html

REST v.s. SOAP

Example: querying a phonebook application for the details of a given user using user’s ID.

use REST

http://www.example.com/phonebook/UserDetails/12345

use Web services and SOAP

<?xml version="1.0"?>
<soap:Envelope
xmlns:soap="http://www.w3.org/2001/12/soap-envelope"
soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">
 <soap:body pb="http://www.acme.com/phonebook">
  <pb:GetUserDetails>
   <pb:UserID>12345</pb:UserID>
  </pb:GetUserDetails>
 </soap:Body>
</soap:Envelope>

Differences between SOAP WS and RESTful WS

• 首先，两个的 工作/使用 流程完全不一样
  • in SOAP, service provider registers their services to UDDI, then client looks into UDDI for certain services, and client use WSDL to access web services
  • in RESTful, it simply use HTTP to make calls between client and server
• SOAP is stateful; RESTful is stateless
• SOAP use XML; RESTful use JSON, XML, CSV…
• SOAP support HTTP/s, TCP, UDP; RESTful support HTTP/s
• REST is much more lightweight and fast

When to use REST?

• Limited bandwidth and resources
• Totally stateless operations
• Caching situations

When to use SOAP?

• Asynchronous processing and invocation
• Formal contracts
• Stateful operations

其实，说了这么多，总结起来就一句话，除非万不得已一定要用SOAP，其它情况都用RESTful。而什么情况是非用SOAP不可呢？那就是Stateful operations。 至于这种带状态的网络请求，设计上是否合理，那就是另一个话题了。（有一种叫做legecy application的东西）

Server Response Format

• XML
• JSON
• CSV

<parts-list>
 <part id="3322">
  <name>ACME Boomerang</name>
  <desc>
        Used by Coyote in <i>Zoom at the Top</i>, 1962
  </desc>
  <price currency="usd" quantity="1">17.32</price>
  <uri>http://www.acme.com/parts/3322</uri>
 </part>
 ...
</parts-list>

Example

JAX-RS with Jersey

e.g. RESTfulDemo.zip, RESTfulClient.zip

Steps to Create RESTful Services:

• import jersey api using maven
• write business logic method
• add annotation @Path("/XXX/{X})", @Get, @Produces(MediaType.XXX)

Steps to Consume RESTful Services:

• config -> client -> service ->
• service.path(…PATH…).accept(…MEDIA-TYPE…).get(…VALUE-TYPE…)

http://www.java2blog.com/2013/04/create-restful-web-servicesjax-rs-using.html

REST with Spring

e.g. ConsumeRestSpring-demo.zip, BuildRestSpring-demo.zip

Steps to Consume Spring RESTful Services

• create an POJO class and use jackson annotation to contain the data
• create a RestTemplate object -> use its getForObject(url, class) method
• https://spring.io/guides/gs/consuming-rest/

Steps to Build Spring RESTful Services

• Add dependencies using maven
• Create a resource representation class
• Create a resource controller using @RestController and @RequestMapping
• Start the service using SpringBootApplication
• https://spring.io/guides/gs/rest-service/

Other Spring-REST Peojects

• TaskManagerAPP.zip reference here
• AccountManagementSystem.zip

Testing Tools

• POSTMAN(Chrome)
• SOAPUI

Links

• REST Tutorial