Java SOAP client stub generation with service endpoint determined at runtime - java

Previously, I've written SOAP clients in Python and used the SUDS library. Without getting into the details, the "stub" generation is really quite dynamic as it's done at runtime and, with Python being so typeless, I'm able to reference the expected methods generated by the WSDL without a pre-compiled stub. I'm fine with generating a stub with something like wsimport, because it's great to have the composition of SOAP messages being handled via a nice Java object structure. So, I'm not looking for a dynamic generation mechanism akin to SUDS in python.
My problem is that all the simple JAX-WS examples I see are for what I'll call a "statically located web service". What I'm trying to do is connect to a web service with a known WSDL from which I could generate stubs at compile time but whose location is only known at runtime. For example, say I want to access Microsoft SharePoint Web Services. Wherever my application is deployed, there will a different SharePoint server (or servers) running which will need to be specified at runtime. All the simple examples I've seen have the service location URL hard-coded into the stubs through wsimport. Is there a way to generate stubs but supply the service location at runtime?
I'm really surprised not to find any examples of this because I figure what I'm trying to do should be very common as Web Services go. Perhaps the answer is that I can't be lazy and get a nice objectified version of the WSDL methods if the server location is only known at runtime. I've seen SAAJ examples but there, of course, I have to generate the SOAP messages by hand myself. That would be such a shame when the WSDL is known at compile time. Can't I have my cake and eat it too?

If I understand your question right, you want to connect to multiple web services that expose the same WSDL but are located at different addresses and your client contains only the address of the service used to generate it?
In that case have a look at this post: Changing WSDL url (endpoint) in JAX-WS client.

Related

How to connect WSDL file in my application using SOAP service?

I am doing a project using Java and BPEL. I successfully created webservices in Java and integrated them using BPEL. All i generated a single output WSDL file. Now, I have to use this output WSDL file in my application using SOAP communication. How can i do that? Is there any help out side for such scenarios? Walkthroughs are really appreciated..
Depending on the architecture of your application (Standard Java, Spring-based, ...) there might or not be a documented procedure to consume a SOAP-based webservice.
On the other hand, you're always free to pick a webservice development framework to handle that. For instance, you could pick either CXF or AXIS2 (I believe these are the two most popular frameworks for Java WebServices). Each of these frameworks provides a tool called "wsdl2java" that helps you generate client-side/server-side/both Java classes. Then, you can easily add those classes and the requireds libraries to your application.
Having used CXF in the past, It even does provide several way to consume a webservice
Generating the client-side classes
Using CXF dynamic client factory : basically, you'll retrieve an endpoint proxy from a factory object.
Hope that'll help
I start with SoapUI (or downloadable from sourceforge), that will let you consume the WSDL and fire off requests against your server. Typically I'm hitting someone else's webservice, and trying to figure out what the data looks like before I start wiring my code together, but in your case its just a verification that the services would be/are working.
Then, as #KHY said, you can automatically convert the wsdl into java with a wsdl2java and start coding (look under the Related list on the right panel of this SO screen)
If it is a Java application, then the easiest way to consume a service is using JAX-WS. It's really easy to create a Web service client from WSDL.
See this link
Once you deploy the BPEL project on server, then refer the WSDL with http://server:port/application/YourBPELProjectService?WSDL in the consuming application. You will need to write different client code based on the BPEL type - Synchronous, Asynchronous etc.

WebServices client - Dynamic proxy versus Stubs created with wconsume

I created a Web Service using JaxWs. I belive that exist two ways to consume a web service in the client.
using wconsume e putting the generated classes as stubs in the client.
using Dynamic Proxy, whitch means, there wil be no files to be send to client as stubs.
I imagine that the only advantage of this approach is that if the wsdl changed, there will be not need to generat stubs files. However it doesn't look too practical, as I will probably need to change something in the client code and recompiled anyway. I didn't use this tecnichy yet. I found this option when I was reaserching the reason why I need to generate proxy file when developping Java client but I didn't when I using .Net.
Then, I have two question:
What's the difference between stubs and Dynamic Proxy tecnich?
Why .Net client doesn't need proxies files? Or is there the files automaticlly generated and I don't know where to find? Am I loosing performance or security when using stubs versus dynamic proxy?
1.What's the difference between stubs and Dynamic Proxy tecnich?
JAX-RPC is deprecated.
The new standard is JAX-WS.
JAX-WS allows programmers to invoke a web service, as if they were making a local method call.
For this to happen a standard mapping from WSDL to Java has been defined.
This mapping correlates a wsdl:port definition with a Java Interface which is called Service Endpoint Interface (SEI).
The SEI is the Java representation of the web service endpoint.
At runtime JAX-WS creates an instance of a SEI that can be used to make web service calls by simply making method calls on the SEI.
Now the way used to create an instance of a SEI is via the dynamic proxy class.
It is called dynamic proxy since it is created dynamically.
No stubs are need to implement a proxy, but the SEI must already have been implemented in order to be used.
The proxy uses/is based on the stub classes to function, which have been generated by the WSDL.
So the stubs are a prerequisite.
So there is no separation of techniques as you say in your post.
You have misunderstood the concept

Java web services client

I want to build a web services client that takes wsdl link as the input and generates java classes. I know we can do this directly using Netbeans IDE where we provide the wsdl location during project setup. But I want the wsdl location to be provided when the client starts running. How do I do this?
Is the location that will be provided just used to specify the SOAP endpoint (for a web service whose WSDL was known at development time), or will it be a completely arbitrary WSDL?
In the first case, the web service client that was created by Netbeans has methods that accept an alternate SOAP endpoint URL. You can call those to use the client with a server whose location is not hard-coded in the client.
If however, the WSDL describes a completely unrelated service, how are you going to write Java code against it? You cannot use any interfaces derived from the WSDL (because they are not known at development time). You could only have a very generic SOAP client, where the user almost directly types in the XML that will be sent.

JAX-WS client: JAXB required?

I need to "dive into JAX-WS programming".
So, I played around with Netbeans, after 20 or so erroneous attempts,
finally managed to let a web service client execute a web service.
I noticed, that a lot of code is generated, especially JAXB classes
for the web service response.
My current task is, to write a web service and web client completely
by hand.
Is JAXB required at all? Is is part of the standard anyway? What would happen without it?
EDIT:
Seems that the answer is given here
You can see Developing Web Services with Java 2 Platform, Enterprise Edition (J2EE) 1.4 Platform
I took a wsdl and used eclipse to generate the service, serviceLocator, ws interface, ws binding stub, ws proxy, and then the client code. I added a main method and was able to hit the webservice successfully.
I used this tutorial as a guide with the url below and no, there are no jaxb objects as I'm not pulling any objects back in the simple example I used. I was just hitting some methods that pulled back a boolean value.
http://px.pats.no/px/Eclipse_tutorial.html

Testing Web Services Consumer

Here are some tools that I have found to test web services consumers:
http://www.soapui.org/
https://wsunit.dev.java.net/
Are there any others? I would prefer testing frameworks that are written in Java or Python.
I have used soapui by a maven plugin. It can create junit-linke reports to be run and analysed like unit tests. This can be easily integrated in continious build, also with the free distribution of soapui.
I've used Web Service Studio.
Web Service Studio is a tool to invoke web methods interactively. The
user can provide a WSDL endpoint. On clicking button Get the tool
fetches the WSDL, generates .NET proxy from the WSDL and displays the
list of methods available. The user can choose any method and provide
the required input parameters. On clicking Invoke the SOAP request is
sent to the server and the response is parsed to display the return
value.
This tool is meant for web service implementers to test their web
services without having to write the client code. This could also be
used to access other web services whose WSDL endpoint is known.
Also the Web Services Explorer in Eclipse which comes as part of the Web Tools Platform.
Through UDDI and WSIL, other applications can discover WSDL documents
and bind with them to execute transactions or perform other business
processes. The Web Services Explorer allows you to explore, import,
and test WSDL documents.
The Grinder is right up your ally with both Java and Python, that handles most web services, (SOAP/REST/CORBA/RMI/JMS/EJB) etc.
http://grinder.sourceforge.net/
You really need to be more specific: What is it that you want to test in your WS-consumer? That it calls the right WS? This looks a bit pointless - WS are a perfect place for mocking whatever may be called - without anything being called.
In order to test the consumer you'd otherwise be writing a Webservice that mocks the original, right? I'd suppose that the communication protocol that goes through the wire is not the clients domain - e.g. it's generated. So the only thing a WS-consumer's client sees is the interface. And there's nothing to test in an interface.
It might be that I completely misunderstood your question - please clarify if I did. I'll revise the answer then.

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