Can we create SOAP and REST Web Services in an single application.
If "YES" then how to distinguish between them while performing testing
Applications usually expose either SOAP, or REST services. However, if you have both customers who prefer REST (e.g. for simplicity) and who prefer SOAP (e.g. because it is better supported by their integration tools and standards), it might be right to provide both SOAP and REST. Of course there is a drawback of higher development and support cost, so you need to consider whether it's worthy to do both.
These services should share business logic as much as possible to avoid inconsistencies.
Regarding the testing you simply test the set of REST services and the set of SOAP services. In addition I recommend to test the REST and SOAP service for the same function and compare whether they produce the same result (in service response and within application).
Related
We are using SOAP based web services to let end user schedule service appointments. Our portal is WebService client & we have a number of Vendors(who are spread across the globe in various timezones) who are building Webservice Server operations.
We are thinking to build it as a contract first SOAP based web services so that we have tight control(interface based e.g. date-time format should be standard xsd:dateTime etc.) over what can be sent & received as part of XML messages for possible success & error scenarios(via different error codes). We want to keep single client code for all the vendors. We would like to determine
1) Should we think about using RESTful web services?
2) Is there any way the vendors can use RESTful services also if they want at their end(by sticking to our WSDL contract) & we use SOAP at our end
First a little bit about,
REST (Representation State Transfer) is an architecture style to develop webservice. In which data and functionality are considered as a resource and can be accessed via URI (Uniform Resource Indicator). It follows client server architecture and uses stateless protocol (usually HTTP). Typically in REST webserivces resources are acted upon by GET, PUT, POST,DELETE operation. Generally we use JSON to exchange data between client and server. It is light weight.
On the other hand SOAP (Simple Object Access Protocol) is a XML based mesaage protocol. Which is generally used on enterprise level to define their own interfacing and operations as services. It also follows REST architecture.
So basically, it is a RESTful webservice.
Now to answer your question,
It seems you are going to expose your webservice client on enterprise level. Which is going to be used by many vendors to implement their own webservice server.
So, it is perfect, you go with SOAP webservices.
You will define the skeleton of the webservice like Message formats, Operations, binding etc which is called WSDL. It is widely used standard and very easy to understand by any third party. Something called WADL is used for REST services also but it is not very user friendly.
The same contract (WSDL) will be used by your vendors to implement the webservice on their server in Top to Bottom approach using some API, for example JAX-WS.
This way you will have a tighter control over your operations, formats, security etc. in a single contract (WSDL).
Now if a vendor wants to use REST webservice instead of SOAP. You can build a JAVA proxy on top of your client. Which will convert your soap messages into REST to send/receive request/response to REST webservices. But you can not dictate your contract in this approach. Although, You can recommend vendors to build their own proxy to handle your SOAP webservice requests. This way your contract will be intact.
If you are going to expose your webservice client for small applications then it is alright to go with REST but if you are an enterprise and going to expand in future, you should go with SOAP for robust features and easy maintenance.
Disclaimer: please do not consider this answer as really serious.
Well, I think question too abstract. Why do you asking it? Because you see yourself that currently everything is RESTful? Then you'r right. You can do any protocol. But if you will do REST with JSON instead of XML, everybody will thank you. And if you will use 40 years old technology for creating modern service, then probably not. Same for your contractors.
The only advantage SOAP seems to have in your situation is that it is already implemented.
SOAP is a complex standard with unfriendly implementation and verbose implementation - i.e. hard to work with and maintain. Also note that you are not even using it "by the book" since your security is external to it and not using ws-security
REST based interfaces would make your and your users' lives easier. I suggest you take a look at standards and tools like swagger for building APIs.If you're running on premise you can take a look at API gateways like tyk If you're running in the cloud you also take a look at AWS API Gateway
I am new to web services. I am studying it through various sites. Got confused for below query.
Why do we need client to test SOAP web services, but not for REST?
Thank You :)
Cheers!!!
Nitin
The short answer is "you don't mandatory need client to work with SOAP web services, and you may wish to use a client for ReST service".
Having a SOAP client makes things much simpler. In case of SOAP web service there's thing called WSDL, where your client can get all the information about this service - classes, operations, etc... all together called service contract. Based on this knowledge, a decent client will present you with user-friendly UI to make SOAP calls and display output. But, again, if you're skilled (and crazy) enough, you can do it even through telnet command.
The ReST is more general term. Actually SOAP web services can be referred to as ReST level 0 services. Since ReST is more general, by definition there are more general rules. For example, there's no common rule where to get service contract. On the other hand, ReST services nowadays are written the way that they can be simply consumed from e.g. JavaScript. This means that you can use tools like Postman or DHC Chrome extensions to make requests and see results - and they will work as a client to your ReST service.
We have implemented a project based on Spring MVC REST, which also has Spring Security.
Now we have a client who is only SOAP compliant (To implement SOAP we want to use Apache CXF), so we have two options.
Write and Adapter Service which takes SOAP as incoming request, converts them to JSON calls and vice-versa.
Expose the existing Spring MVC REST Service as both SOAP and REST.
Concern for option-1 is that if writing an adapter service just to support new SOAP protocol is worth it? Regarding Option-2 I am yet to come across an example which shows Spring MVC REST service exposed as SOAP/WSDL approach.
Thank you,
Himalay
I followed the second approach, as with the first approach there is lot of duplication, I would follow the first approach if you have a matured REST framework used by many clients, and avoid introducing any bugs.
Does a RESTful web service (e.g. in a JAX-RS implementation) support both contract-first (top-down) approach and contract-last (bottom-up) approach?
Do RESTful web services support both contract-first and contract-last approaches?
It depends on what tools/frameworks you use.
What you are talking about applies to a SOAP web service and its accompanying WSDL.
A WSDL describes what a web service expects as input and what should a client expect as output. It defines the contract to be followed in order for both parties to communicate with each other. You can obtain the WSDL by doing contract-first or contract-last and you can later use this WSDL to generate code for a client stub or a service skeleton.
But doing REST isn't the same as doing SOAP. Processes that worked for SOAP (a protocol) can't necessarily be applied to REST (an architectural style) just because we are familiar with them.
Unlike SOAP that exposes methods and method signatures, REST exposes resources. An understanding of the media types used in the exchange of those resources is all a REST client needs in order to communicate with a REST web service. There is no need for a separate document to describe the resources.
Because of the HATEOAS principle, REST clients are more dynamic and can adapt to other services that communicate using the same media types. Exposing static service description documents would be limiting for a REST service.
Having said that, there are REST tools that do expose a description document, for example Jersey who exposes a WADL (contract-last). I'm sure you can use the published WADL to build client stubs and I don't see a reason why you couldn't write the WADL by hand (contract-first) and use it to generate stubs and skeletons. But as I said, that might not be the best solution for REST.
Here are some posts you might want to read to form an opinion if contract-last or contract-first approaches make sense in REST:
Does REST Need a Description Language?
Why the slow WADL uptake?
There are 2 types of web-services as I know. First one is custom xml formatted messages and the second one SOAP standard xml messages. What are the differences between them? Which one is better, what are pros and cons of each of that two approaches?
By "ordinary" I assume you mean RESTful services. This discussion would be a long one, so I'll try to give you some key points:
RESTful services are the most used flavor of Web Services. They are closely linked to the functionality and principles of HTTP and can be accessed as simple as a GET request (other operations are POST, DELETE and PUT). The core concept is the "resource" which is identified by an URI. Common formats for REST are XML and JSON. It's a pretty straightforward and easy to use technology, which is what makes it so widely available.
SOAP web services are based on XML, most of them adhering to the RPC-style of app design (calling remote methods on a server and getting a response), and use 3 main pillars:
WSDL - Web Service Description Language - used to describe a service in terms of available operations, parameters, etc.
SOAP - Simple Object Access Protocol - used to construct interaction messages between the entities involved (client, server).
UDDI - Universal Description, Discovery and Integration - used to classify and publish available web services to a repository and enable discovery by potential users.
SOAP Web Services tend to have high overhead and generally have very verbose messages, but may be good if you need to implement more complex functionality and interaction in your application.
Strictly speaking only the Soap services are webservices. They are based on the WS-* Specs standardisized by W3C and Oasis. Sometimes a also reffered as Webservice are so called POX-Endpoint (Plain old XML) or REST Endpoint, which allows you to simply get a raw XML via HTTP GET.
SOAP Services carry their schema in form of a wsdl endpoint (usualy append ?wsdl to the service endpoint), so there a lots of tools to create proxy objects and hide the complexity of the webservice call. With POX Services you need to know which schema to use from e.g. the documentation.
SOAP Services carry the payload inside the SOAP Envelope (an XML Schema with header and body with the payload in the body). Having a header independent from the payload allows to reroute the content, sign and encrypt, authenticate etc. without knowing the content. But you pay by additional overhead in the message itself.
POX on the other hand leaves all that to the webserver and relies usualy on HTTP for authentification and compression. Encription and signing had to be done by your system. It is low overhead but also low discoverability.
Whats works best for you depends a lot on your scenario. If you work in a .Net or Java World, you often find it simplest to create a proxy and use that to work with the webservices as remote objects. You get a well build infrastructure and a comfortable programming experience. If youre environment does not support the proxy generation or if it had to be called from anything, POX might the very much more lightweight way to go.
"Web Service" refers to a more abstract and general concept. We can say that anything that can be served on web is a Web Service. SOAP Web Services or RESTful services are special kind of Web Services which has wide acceptance and has their own standards. While SOAP services are built on a new XML based standard, RESTful approach makes use of existing HTTP methods, hence more widely accepted (to my experience).