WCF communication with java web service - c#

Background
I'm primarily a .Net developer with limited experience in Java. I have a WCF web service that needs to communicate with a 3rd party Message Queue Server in order to send and receive files. The 3rd party has provided a Java API in order to access their Message Queue Server.
I've done some research into the best way to move forward and now I'd like to get some feedback from anyone with experience with a similar situation.
After some digging I determined that one option is to create a java web service in Eclipse and host it on Glassfish. This java webservice would reference:
The java api provided by the 3rd party thus allowing the 3rd party to send the xml files to us.
My existing WCF service in order to pass along the xml to be processed.
So the incoming xml file would flow as follows:
3rd party -> Java WS -> WCF WS
This incoming flow is only half the equation since my WCF web service can also initiate communiation with the third party. So I need an outgoing flow as well.
One option would be to reference the Java WS from my WCF service. However then the 2 web services would each be referencing each other. Is this considered a circular reference (bad practice) when 2 web services reference one another?
If option 1. is considered bad practice, my other option would be to have one of the web services poll the other service.
Other options?
Summary Questions
1. Any insight into the circular web reference question above?
2. Am I on the right track in general?
3. Any suggestions or personal experience you can provide?
Your insight is very much appreciated.

My first thought would be that if it's a quick RPC type call, provided you're calling a different web services for the The call back, I wouldn't be too concerned about a circular reference. Technically you're sending messages "by contract" So as a good practice put your contract definitions in a different project to your service implementation.
If the .NET processing takes a bit of time it may be worth it to use a message queue and a worker service as well.
The other consideration is to find out what MQ infrastructure they're actually using. You may be able to avoid the web services altogether as there are .NET connectors for a lot of MQ providers, like
MSMQ (obviously)
ActiveMQ http://activemq.apache.org/nms/
& WebSphere MQ http://www.redbooks.ibm.com/abstracts/sg247012.html
Just to name a few. There are also MSMQ bridges.

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WCF or Web API for windows form application [duplicate]

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I've spent a few months trying to grasp the concepts behind WCF and recently I've developed my first WCF service application.
I've struggled quite a bit to understand all the settings in the config file.
I am not convinced about the environment but it seems that you can do amazing stuff with it.
The other day I've found out that Microsoft has come out with a new thing called ASP.NET Web API.
For what I can read it's a RESTful framework, very easy to use and implement.
Now, I am trying to figure out what are the main differences between the 2 frameworks and if I should try and convert my old WCF service application with the new API.
Could someone, please, help me to understand the differences and usage of each?
For us, WCF is used for SOAP and Web API for REST. I wish Web API supported SOAP too. We are not using advanced features of WCF. Here is comparison from MSDN:
The new ASP.NET Web API is a continuation of the previous WCF Web API project (although some of the concepts have changed).
WCF was originally created to enable SOAP-based services. For simpler RESTful or RPCish services (think clients like jQuery) ASP.NET Web API should be good choice.
ASP.net Web API is all about HTTP and REST based GET,POST,PUT,DELETE with well know ASP.net MVC style of programming and JSON returnable; web API is for all the light weight process and pure HTTP based components. For one to go ahead with WCF even for simple or simplest single web service it will bring all the extra baggage. For light weight simple service for ajax or dynamic calls always WebApi just solves the need. This neatly complements or helps in parallel to the ASP.net MVC.
Check out the podcast : Hanselminutes Podcast 264 - This is not your father's WCF - All about the WebAPI with Glenn Block by Scott Hanselman for more information.
In the scenarios listed below you should go for WCF:
If you need to send data on protocols like TCP, MSMQ or MIME
If the consuming client just knows how to consume SOAP messages
WEB API is a framework for developing RESTful/HTTP services.
There are so many clients that do not understand SOAP like Browsers, HTML5, in those cases WEB APIs are a good choice.
HTTP services header specifies how to secure service, how to cache the information, type of the message body and HTTP body can specify any type of content like HTML not just XML as SOAP services.
Since using both till now, I have found many differences between WCF and Web API. Both technology stacks are suited well to different scenarios, so it is not possible to say which is better, this depends on configuration and scenario.
Properties ASP.Net Web API WCF
--------------------------------------------------------------------------------------------------
End point (mainly) Http based SOAP based
Service Type Front End Back-end
Support caching, compression, versioning No
Framework ASP.net WCF
Orientation Resource Oriented Service Oriented
Transports http http, tcp, MSMQ, Named pipe
Message pattern Request reply request Reply, one way, duplex
Configuration overhead Less Much
Security lesser than WCF (web standard security) Very high (WS-I standard)
Hosting IIS IIS, Windows Service, Self hosting
Performance Fast A bit slower than Web API
In use from .NET 4.0 .NET 3.5
Note: The data is not only my view, it is also collected from other official websites.
WCF will give you so much of out the box, it's not even comparable to anything. Unless you want to do on your own implementation of (to name a few) authentication, authorization, encryption, queuing, throttling, reliable messaging, logging, sessions and so on. WCF is not [only] web services; WCF is a development platform for SOA.
Why I'm answering:
I took huge amount of time to understand the difference between these two technologies. I'll put all those points here that I think "If I had these points at the time when I was wondering around in search of this answer, then I have decided very earlier in selecting my required technology."
Source of Information:
Microsoft® Visual Studio® 2015 Unleashed
ISBN-13: 978-0-672-33736-9 ISBN-10: 0-672-33736-3
Why ASP.NET Web API and WCF:
Before comparing the technologies of ASP.NET Web API and WCF, it is important to understand there are actually two styles/standards for creating web services: REST (Representational State Transfer) and SOAP/WSDL. The SOAP/WSDL was the original standard on which web services were built. However, it was difficult to use and had bulky message formats (like XML) that degraded performance. REST-based services quickly became the alternative. They are easier to write because they leverage the basic constructs of HTTP (GET, POST, PUT, DELETE) and typically use smaller message formats (like JSON). As a result, REST-based HTTP services are now the standard for writing services that strictly target the Web.
Let's define purpose of ASP.NET Web API
ASP.NET Web API is Microsoft’s technology for developing REST-based HTTP web services. (It long ago replaced Microsoft’s ASMX, which was based on SOAP/WSDL.) The Web API makes it easy to write robust services based on HTTP protocols that all browsers and native devices understand. This enables you to create services to support your application and call them from other web applications, tablets, mobile phones, PCs, and gaming consoles. The majority of applications written today to leverage the ever present Web connection use HTTP services in some way.
Let's now define purpose of WCF:
Communicating across the Internet is not always the most efficient means. For example, if both the client and the service exist on the same technology (or even the same machine), they can often negotiate a more efficient means to communicate (such as TCP/IP). Service developers found themselves making the same choices they were trying to avoid. They now would have to choose between creating efficient internal services and being able to have the broad access found over the Internet. And, if they had to support both, they might have to create multiple versions of their service or at least separate proxies for accessing their service. This is the problem Microsoft solved with WCF.
With WCF, you can create your service without concern for boundaries. You can then let WCF worry about running your service in the most efficient way, depending on the calling client. To manage this task, WCF uses the concept of endpoints. Your service might have multiple endpoints (configured at design time or after deployment). Each endpoint indicates how the service might support a calling client: over the Web, via remoting, through Microsoft Message Queuing (MSMQ), and more. WCF enables you to focus on creating your service functionality. It worries about how to most efficiently speak with calling clients. In this way, a single WCF service can efficiently support many different client types.
Example of WCF:
Consider the example:
The customer data is shared among the applications. Each application might be written on a different platform, and it might exist in a different location. You can extract the customer interface into a WCF service that provides common access to shared customer data. This centralizes the data, reduces duplication, eliminates synchronization, and simplifies management. In addition, by using WCF, you can configure the service endpoints to work in the way that makes sense to the calling client. Figure shows the example from before with centralized access of customer data in a WCF service.
Conclusion:
i) When to choose Web API:
There is no denying that REST-based HTTP services like those created using ASP.NET Web API have become the standard for building web services. These services offer an easy, straightforward approach for web developers building services. Web developers understand HTTP GET and POST and thus adapt well to these types of services. Therefore, if you are writing services strictly targeted to HTTP, ASP.NET Web API is the logical choice.
ii) When to choose WCF:
The WCF technology is useful when you need to support multiple service endpoints based on different protocols and message formats. Products like Microsoft BizTalk leverage WCF for creating robust services that can be used over the Web as well via different machine-to-machine configurations.If, however, you do need to write an application that communicates over TCP/IP when connected to the local network and works over HTTP when outside the network, WCF is your answer.
Be Warned:
Web developers often view WCF as more difficult and complex to develop against. Therefore, if you do not foresee the need for multiprotocol services, you would likely stick with ASP.NET Web API.
There is a comparison on MSDN about this
WCF and ASP.NET Web API
For me, the choice was about Who the clients are, and where are they located?
Within the company Network and .NET based clients : Use WCF with TCP binding (Fast communication than HTTP)
Outside the company Network, and use diverse technologies like PHP, Python etc: Use Web API with REST
Business speaking, WebApi lacks of a WSDL, so the developers should document all manually. And if, for example, the WebApi operation returns a list of objects then, the client should creates the objects manually, i.e. WebAPI is really prone to errors of definitions.
The pro of Webapi is its more lightweight than WCF.
Regarding the statement "WebApi lacks of WSDL" there are several ways to generate Rest client. One popular approach is Swagger UI / (Swashbukkle Nuget). This gives a rich interface to understand the REST end point's input and output schema and online tool to test the end points.
JSON LD (Json Linked Documents) is another emerging standard which will further improve the JSON based REST developer experience by exposing the JSON schema with better semantics.
With wcf we can configure and expose the same service support for multiple endpoints like tcp, http.if you want your service to be only http based then it will be better to go with web API. Web API has very less configuration when compared to wcf and is bit faster than wcf. Wcf also supports restful services. If you have limitation of .Net framework 3.5 then your option is wcf.

Sending data via WCF

I was wondering how you can send data from the client to the host. Currently I have 2 projects and one WCF library. One of the projects is a pump which is the client and I want it to be able to send data to the host? Although I may have a misunderstanding of how WCF works. I was wondering if anyone could point me in the right direction. The problem requires me to use WCF. I want to be able to pass a list of strings to the host.
WCF can send data over many different transport protocols like MSMQ and http. It also enables message security, distributed transactions and other more complex features of a distributed system.
You need to create a WCF service, which is available as a template in Visual Studio. The server should be hosted as a stand alone program os as a web application in IIS.
Afterwards you need to create a client, that can communicate with the server.
WCF is however a large and complicated framework and you should not expect to be able to just scratch the surface and build a system. You need some googling and could possibly start with MS own tutorials.
If you need real useful answers you should be more specific about your program and the client and server operations as well as the deployment scenario.
As faester already said, WCF is a large framework and you can not make a good application by just copy-pasting the code into your project.
You should really read into the matter and then create your programming masterpiece.
faester gave you a link, but it's for basic WCF client-server communication.
Here are some good links on sending and receiving data via WCF:
Data transfer and architectural overwiev
Using the Message class
For a simpler, task-oriented view of how to send and receive data, see:
Specifying Data Transfer in Service Contracts
I hope that this will help you and the people yet to come to this question.

Dynamic WCF service coupling on IIS

I am trying to build a service mechanism which should be add-on based and communicating through a publish subscribe system. It must be based on WCF services.
What I have right now is a concept which I can't get to work so I decided to ask you because maybe I am going at this the wrong way (I only just started using WCF).
What I want to achieve is making a single core service with session persistency which can be extended by linking an unknown number of add-on services. I want to set up the publish subscribe system at runtime, not at buildtime, so the core-service should be able to detect what add-on services are available (using the web.config?) and then bind them to the message bus.
From the front end (ASP classic) it must be possible to access any .svc file but, maintaining session, each .svc file must be connected to the message bus.
All is hosted in a single IIS active directory.
Can you give me some hints as to where to look?
I am especially interesed in:
WCF dynamic discovery
WCF to WCF communication on the same host (in the same active directory even)
Thanks in advance, hope you can help!
Update
Thanks for your answers, I'll read up at the links you send me. I'll post my final concept solution here in due time for future reference.
My 2 cents about Publish subscribe mechanism using WCF - WCF is not inherently built for pub/sub mechanism. It is built for Request/Response model of communication. Have a look at the NService Bus for pub/sub here
Talking about Add on services on top of core service, I am not able to get What you want exactly ? Is it the Routing service which you want ? WCF 4 now provides routing service For more information look here The link also talks in detail about the discovery mechanism in WCF 4.
Also have a look the Agatha framework which also have single WCF service and no. of request handlers where in the framework will decide which request handler to call based on each request.
Search for Agatha - Davy brion for more information
I was having a similar problem since I have one common WCF service but the implementation depends on the user's role so it was kind of difficult to do that at runtime.
I found this tutorial on the matter which runs great for my propouses: http://blog.micic.ch/net/dynamic-iis-hosted-wcf-service
I have tested in my env and is very powerful technique. Hope that helps you as well. Cheers.

WCF Test Client that allows me to view/edit the request XML

From time to time we need to test why a certain request coming from our MQ to a WCF service failed. I need to be able to debug the service and find out where it went wrong and resolve the issue. The only information i have is the XML request that was sent to the service. Before we moved to WCF i used a custom tool to send the request to my ASMX debug instance but since we moved to WCF I dont seem to have that option. All the clients i have tried only allow you to fill in the fields through a UI and this is not an option when dealing with huge requests.
Is there a free or open source client that will allow me to do this? I have searched and tried loads but none seem to do it.
Alternatively is there a tutorial or article on writing a test client of this kind? Again i have searched but there seems to be a lack of information on WCF clients and a huge amount on the services.
tl;dr; Im looking for a WCF test client that will allow me to paste in an XML request and send it to a WCF service or a tutorial that will start me in the right direction.
Of course it is not free, but one of our teams is using Altova XMLSpy for that purpose and it works fine.
You can also check (Not sure they will allow you to edit SOAP, but have a try):
SoapUI
WCF Storm
Also check Web Service Studio 2.0 I have tried it will allow you to edit requests.
Not sure I totally understand what you're looking for:
to see the MSMQ messages, you should open the MMC snapin for MSMQ administration on your server where the MSMQ queues live - is that what you're looking for?
in order to create and send out arbitrary XML messages, have a look at SoapUI which is available in a free (and already very capable) version, or alternatively look at SoapBits

Howto make this Windows-Service-Scenario as comely as possible

I have following scenario:
alt text http://static.zooomr.com/images/7579022_e64808b855_o.png
We have a WebService which poses as a search-engine, used by WebApps
But as we all know on 32bit systems and IIS6: 800Mb is the max. alloc-mem for a webapp...
Now I had the following idea, as we are exceeding this limitation:
alt text http://static.zooomr.com/images/7579028_c423e52b46_o.png
Let the WCF communicate with a Windows Service, which isn't affected by this constraint!
But this brings me to some questions:
How can I communicate with a Windows Service as I would communicate as a client with the WCF (having methods with parameters, getting objects as return value, etc...).
After thinking about this a bit, following post came up to me.
But I'm not familiar with this scenario.
Do some of you know some good resource, where I can get the knowledge to realize this scenario (maybe with demo-apps)?
Or does someone maybe have a better idea of how realize this scenario even more comely?
This scenario wil be completely done with C# 3.0 and .NET 3.5(SP1)...
I would definitely use WCF as the communication layer between the web-app and the service. You can host a ServiceHost in your windows service, and serve up any type of WCF endpoint.
A common pattern I've seen is to connect a web layer and service layer using MSMQ (Net MSMQ binding), so that you have disconnected calls, and some buffering to allow for load tolerance. If you don't need the buffering, you can use any other type of binding (Net TCP or even HTTP, although sometimes it tricky to get HTTP setup correctly outside of IIS).
Here's a good tutorial:
http://msdn.microsoft.com/en-us/library/ms733069.aspx

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