So I'd like to connect a wpf c# client to a java backend via web services.
I have a few questions regarding this and I am a bit new to web services so please bear with me..
Would I be using a wcf web service or would it most likely be a java construct (and if so which one?)
Would I be using soap or rest? i know this is a big topic but I'm just looking for which one would most likely be used.
Lastly, would I be able to run java methods via my c#? for example say I have a method that lives on the server called called "Customer GetCustomer(int id);" ... would i be able to call this method in my c# client? And how would the customer come back would it come back as xml and then I'd have to parse this xml and build a Customer object on the client side? meaning, would I have a duplicated class definition on both the server and client, or would I somehow share the same Customer reference?
Thanks in advance!
Expose a SOAP service from your Java backend, and access it using WCF. Easy and painless
SOAP is easier, and requires less work when you use WCF.
Yes. SOAP allows you to define ComplexTypes which would represent your classes, so the C# mappings would be pretty much the same as your Java ones.
I would recommend reading up about SOAP and WebServices in general, that should answer a lot of your questions.
Regarding question number 3, when you expose your logic in Java as as a web service... Now I do not have enough knowlegde on how to deploy a java web service but when you deploy it, what remains is to create a proxy in C# and start calling your web methods.
Elaboration:
Creating a proxy (in .NET web services or WCF) (AKA adding a Web/Service reference) means that you recreate all the exposed classes/types in your java WS methods as local types in C#. These types will be exposed (on Java WS side) using an XML document called WSDL (Web Service Definition Language). This will make a second copy of all the types used in the Java WS webmethods in your C# program, you can call this redundent, but this is the only way that you can communicate with a Java WS from .NET
Afterwards, when your C# program runs, and reaches the call to the proxy of your Java WebMethod, the proxy will transform the web method call's arguments (class instances) used by the WS proxy to XML representation. This is called encoding your object(s) using SOAP, the client creates a SOAP envelope that contains all the necessary data/objects - arguments (encoded with SOAP) and sends the SOAP envelope to the JAVA WS. The Java WS decodes (reverses XML to java instances) the objects embedded in the envelope, and calls the correct Web Method according to some hints also found in the SOAP envelope.
When the call to the Java WS is completed all the instances that must be returned to the client (if any) are also encoded using SOAP, and sent to the client as a response to the WS call.
Related
I have to implement SOAP based communication between a .NET application and a local courier service. They have provided good documentation of their SOAP service with php samples and wsdl schema at http://www.rapido.bg/soap_help/, but I cannot find my way in implementing it for .NET with C#.
I looked at similar problems online and first tried to add the wsdl as Service reference which didn't create the necessary classes, then tried to add it as Web Reference, which generated the classes and methods, but could't generate some of the parameter types as expected. For example the login parameter was generated as string, whereas in the wsdl it is defined as xsd:struct and in the php sample its created and passed as an anonymous class with two fields.
I tried to implement the communication using web requests and building the SOAP messages manually following some other approaches, but still couldn't get it right.
It will be great if someone can get a simple app working or just let me know how to do it.
Thanks.
Try using WseWsdl2.exe, it will generate C# or VB.Net classes for you that can be used to communicate with the SOAP service of your choice.
I am having an Existing ASMX webservice in Production. I need to add RESTFul capabilities to the same for Rest Clients.
As per my understanding it must be as simple as adding a HTTPHandler (restversion.ashx) implementing IHTTPHandler and calling Business methods while serializing the return objects to XML or byte Stream. Which will be received and interpreted by REST Clients.
Though, while searching on the similar topics, it is not recommended and Can't be done.
Please suggest me..
I would recommend using WCF Web API. There are several tutorials at the end of this page. As you can see it is pretty easy to build simple RESTful service. There is also built in test client so you can test your REST service using your browser.
Assuming you want to continue your investment in the legacy ASMX technology, you can create a new WCF REST service, and have it call the existing ASMX service as a client, in order to perform its functions.
Can I write a web service that implements the same methods and returns the same custom objects using both C#/WCF and also Java Web Services? And if so, can I then access the web services using a single web reference but with different addresses?
I'm asking because I have to host a web service that has a GetCitations and GetTerms method for publically exposing our database content. We are on IIS, so I was going to do it with WCF. However, other partners in the project also have to host an equivalent service and they are all Java based.
We are then building a software app that needs to connect to any number of these services (as defined at runtime by a user). I am expecting that we can have one set of classes to connect to these services (but with different endpoitn addresses), but am not sure whether I'm right in expecting this to work.
Is this possible?
And what considerations/restrictions are there?
Thanks.
It shouldn't be a problem, if you make sure that both services have equivalent wsdl files and you use http/soap binding.
I am not sure about using the binary (net.tcp) one with WCF, though. It might be a problem.
One way to do it is to use JAX-WS (Java 6) to expose a method as a web service.
The JAX-WS stack allows for automatically generating the correct WSDL at runtime.
The .NET team can then take that WSDL, and use standard tools to create a mock implementation of that WSDL. This mock implementation is then used as the actual .NET implementation, and you then use standard tools to generate the WSDL for that web service.
You now have to web services with the same semantics each with their own WSDL.
Both Java and .NET can implement a SOAP compliant web service, so the answer is yes, you can write a .NET and a Java webservice that implement the same WSDL.
My understanding is that a c# based client "prefers" SOAP because when you add a web service reference it creates a proxy class from the wsdl found at the url you specify.
Which almost makes it transparent to the c# client that we are even using a web service, it almost feels like we are using a local class library. you call methods and you use objects.
My question is can REST achieve the same affect. I assume that it can't since it doesn't have wsdl and thus visual studio can't generate a proxy class for it. But Please correct me if I'm wrong?
A "run of the mill" REST service cannot achieve the same kind of tight integration with C# - mostly because it lacks the metadata that a SOAP service will provide (with a list of methods and their parameters and all that stuff).
The WCF Data Services (built on top of REST) do work much the same way as SOAP services, since the OData protocol contains extensions for pure REST services that provide metadata information needed to create a good, useful client-side proxy.
REST can be used to generate client side class libraries. For Example You can create proxy classes for MS generated REST services. In fact MS is actively pushing this model for Entity Framework based WCF DATA Services, e.g. those used by Silverlight and RIA applications. check out MS ODATA framework for REST which involves creating client objects out of standard REST queries.
http://msdn.microsoft.com/en-us/library/dd673930.aspx
At my last place we used to do a lot via XML SOAP - Basically the client would construct an XML request which would contain the service to invoke and send that onto a host and port
The server would then take that service request and figure out the class and method to call and serialise the request / response
This was helpful as we had Java and C# and wanted to segregate the two
If you had to build this out what libraries would you use?
Specifically how the main machine translates a service name => class and method invocation
In C# I'd look at WCF in the first instance, that allows you to create web services very simply.
For Java, I have experience with axis2 from Apache. It works well enough that I would recommend it and use it again on a SOAP project.