My standard WCF/ RESTful service is going to return big complex object.
In WCF as and when someone adds the service reference it creates a proxy of it, i.e. I am exposing data contract to client and its strongly typed at the client level.
How are we going to do with RESTful service, is there anyway to the same for RESTful service.
One of the benefits of RESTful services is that they are lightweight. That implies no infrastructure like WSDL files, proxies, etc.
RESTful services are not self-describing, so you don't have to worry about providing a WSDL file; maintaining all the schemas online, etc.
If the payload is complex, then why are you using REST? Just because it's a fad? Do the operations on your service correspond to HTTP operations on "resources" as the HTTP Protocol specification defines it?
If not, then don't use REST.
Related
I have a system (kind of aggregator) that integrates with hundreds of different SOAP services - most of them do the same business functionality, but each service having different data structure in SOAP request & very few having 2 API calls to complete one transaction.
The present service integration workflow is
create stubs from WSDL
map data to the generated stub api
setup a new endpoint to fire this api
I see this a repeated, unintelligent work & requires development effort for every new service integration.
Was there different approaches to integrate with lot many systems? Any libraries that can generate soap requests based on configurations, or I have to rely on some Java SOAP, Spring lirbaries to create custom SOAP xml request from my own configurations? I see Spring's WebServiceGatewaySupport for webservice client but requires stubs created from wsdl?
Is it wise to define soap request xml as templates for every service, generate xml with input data?
Other ways I thought was to develop each integrations as independent microservice layered under an API gateway that routes each requests to specific service. But this design approach will have hundreds of services running, consuming more resources (in case of Spring boot).
Generate stubs & deposit the jar to disk, load this jar with a classloader & use the stubs using reflection - not so simple, I believe.
Use of serverless looks promising but is not possible immediately.
I have a spring mvc application which runs correctly,now another colleague wants to call the same functions from another application but he needs REST URL of my functions.
how is it possible to provide the same functionality through spring REST?
is it just with new annotations .please provide some resource to show me how to do it.
when server has a service, only legal clients which had any contracts with server can access it. And clients can use service by the way such as: use RestTemplate to get/post request to URL of service, and clients can get data as JSON, or XML type if you have an equivalent object as this image:
Also, a service can be support as a interface, ex: google search is a service supported by google, but it's not rest service.
If you know each other URL address you can consume each other REST API from java code by using RestTemplate object.
I would advise you to go over the Spring starter guide which deals with that issue, here is the link (Consuming a RESTful Web Service):
https://spring.io/guides/gs/consuming-rest/
After read the Gordon's article about Best Practices to build Enterprise Application using Spring Framework, I would like to share some ideas about the Service layer.
My architecture represents exactly what Gordon described in this image http://gordondickens.com/wordpress/wp-content/uploads/2012/07/Spring-App-Layers.png
The application is complex, has a heavy business rule and demands to use different resources like Database, SOAP, REST and file handle sometimes in the same use case.
For this scenery that I have described above, I have a Service class that needs to perform SOAP and REST requests and handle some database data. So, I have autowired in my Service class a SOAP and a REST component and the Repository to handle the database stuff.
I'm concerned about if this is the best approach do handle the integration between my Services and the resources like SOAP, REST, Database and etc.
Thanks
So, I have autowired in my Service class a SOAP and a REST component
and the Repository to handle the database stuff.
Sounds problematic even though it will work.
Think about the dependency between layers. Service layer will depend on Repository layer (Business logic layer will depend on data layer). Service integration layer (or service communication layer) for incoming requests will depend on the Service layer. But the data layer does not depend on the service layer. Nor the service layer depend on the inbound service invocation layer.
So, remove the SOAP and REST components from the Service class. To the SOAP and REST components, wire the Service instance (i.e. avoid SOAP and REST components wired into the Service, do it in the reverse direction).
This way, when you want to support another integration protocol (say JMS), you do all such work not by modifying your service.
Your data access seems to be fine. I hope your Service accesses the repository via DAOs.
So, I have autowired in my Service class a SOAP and a REST component
and the Repository to handle the database stuff.
Sounds fine. You are using dependency injection, this means they can be easily tested or altered.
We are planning to develop a big application in web, our current plan is to create a WCF service for each class in the Business layer. Is this effective? I want to know where can we use WCF in a big web application and main advantages of using it
we have these projects
1) MVC3 with Razor that handles UI
2) Class Library Project that communicate with Database
3) WCF Project
Method we using
1)Creates UI and Model in MVC
2)Makes dll that communicate with UI (eg:Save function/Update function) using ClassLibrary Project
3)The Class Library Created is Added (Added to Bin) in WCF Project
4) Builds the WCF and Host It in Server
5) The Hosted Service is Used in MVC Project for Communication with DB
Our Technical lead is saying it is light weight and more secure but i am wondering why he is saying to use WCF for whole appication
First ask this question, why do you need a service layer, when it could be achieved by a separate application. If you want to achieve this for just loose coupling, then it does not makes sense.
In my opinion, the service layer would be useful for exposing your data (dal-layer) and not Business Layer. For example take twitter. Twitter exposes it data over Web Services. What you do with the data is completely your interpretation. The data could be consumed by many application over HTTP. So your client could be remotely situated and need not to be on the same server as your application. The business layer could change based upon interpretation of data. The consumer, then need to worry about latest changes and including latest DLL. It will just consume the webservice. Also mocking your service would be pretty easy and you could write your NUnits tests very easy on your Business layer then. I would also recommend you to have a look at ASP.Net Web API, which provides restful way of exposing your services and data(with inbuilt capablity of exposing it as JSON). The RestFull service has many advantages over WCF, like you then need not to worry about WSDL and etc. The interface always remains same. Consuming a RestFul service is very easy.
As again with the twitter example. The clients consuming twitter api's are not situated on same server. So it makes sense to expose it over HTTP.
But if you do not have such a requirement(Client is not remotely situated), then exposing your data over web services does not make sense. Then a separate application will give you loose coupling and that should be good enough for you. Also exposing data on HTTP will have some performance impact too.
UPDATE 2
I understand the scenario you are trying to implement and I think its perfectly allright. By light weight he means, from your WCF service he would do interaction with Database and then send light weight DTO's for each action and controller as per requirement. So basically your WCF would do nothing but invoke methods from your class library, would fetch some Business Object and Convert it back to DTO(as required by your action to render UI) and send it to Controller.
Also make sure, you use Dependency Injection for your Services, so that you could write NUnit tests for your controller with mock data and hence no requirement of Database for running your NUnits
My preference is to have the service layer be a completely independent application that can be consumed by many applications. It makes projects, especially large ones, much easier to scale, than if you were to create your service layer inside a single web application.
Unfortunatly to tell you. Using WCF is less effective. The main purpose to use WCF it to let your data can be accessed with any client application. not just web application. you may also have a Silverlight or winform. WCF has nothing to do with "A BIG" web app.
im trying to understand where WSDL's fit in, in a typical web service backend application. i am coming from a Spring background and in my experience so far, in Spring, each url request gets mapped to a specific controller class via a dispate servlet running in the web container. you can specify which url matches a given controller via xml config or from annotations.
is using a WSDL the same thing as using an xml config file to map url requests to java objects?
Thanks in advance. im moving from Spring to standard j2ee/EJB3.
WSDL is just a description of Web Service interface, most Web Service systems generate those descriptions on fly like for example when you create asmx web services you can generate WSDL on fly by typing http://yourhost/yourwebcontext/yourwebservicename.asmx?wsdl and it will return you the description of that web service. Then you can use a tools that generate stub proxies for coding using those descriptions automatically, for example in Visual Studio when you add an Web Service Reference those operations are done automatically
No, WSDLs are not like a dispatch servlet.
A WSDL file is a description of a web service (SOAP, REST, etc.). A WSDL can (theoretically) be used by anyone to generate executable code which consumes the web service described by that WSDL.
From the WSDL tag info:
"WSDL" stands for "Web Services Description Language." It is an XML language used to describe a web service to code that wishes to consume it. It describes the messages sent and received, the possible faults, and the communication and security requirements.
From WSDL Essentials:
In a nutshell, WSDL represents a contract between the service requestor and the service provider, in much the same way that a Java interface represents a contract between client code and the actual Java object. The crucial difference is that WSDL is platform- and language-independent and is used primarily (although not exclusively) to describe SOAP services.
Using WSDL, a client can locate a web service and invoke any of its publicly available functions. With WSDL-aware tools, you can also automate this process, enabling applications to easily integrate new services with little or no manual code. WSDL therefore represents a cornerstone of the web service architecture, because it provides a common language for describing services and a platform for automatically integrating those services.