spring-ws -- how to create java-interface from WSDL? - java

I'm creating a WSDL-first webservice with spring-ws in gradle.
Some examples I have been looking at
(e g https://spring.io/guides/gs/producing-web-service/ )
it seems they will only generate the java-classes from the XSD-schema,
but no java-interface (or abstract-class) from the WSDL service-operations?
Also, in the spring-ws doc, it says "... in Spring-WS, writing the WSDL by hand is not required ...".
Is it correctly understood that spring-ws will not generate any java-interface or class for the actual service itself?
Is it possible to override this default behaviour and force it to do so?
I would like to ensure the full WSDL is correctly and completely implemented...

With spring-ws you can build contract first WS, although it is not necessary to build your WSDL, because it can generate it dynamically.
For java objects, spring-ws allows you to marshall/unmarshall using jaxb2 or similar. This way, you can obtain java classes from XSD, but this code generation is made by the marshaller.
From a server point of view, you create WS Endpoints that match WSDL operations. That Endpoints are annotated and bound to a request/response java objects. Thus, spring can generate dynamically WSDL, but you can use your own WSDL.
From a client point of view, you need a WSTemplate that needs to retrieve a WSDL (static or dynamic, it doesn't mind). Using this way, WSTemplate ensure you can call all server endpoints, without implementing client stubs or generated code.
I rather prefer to use static WSDL, because dynamic generation can't ensure that your WSDL change if you upgrade Spring or so, and this could break compatibility with your clients.
However, while I am developing I use dynamic WSDL, for the shake of simplicity. Once I have the service I want, I get dynamically generated WSDL (customize if I need) and use it as static. That WSDL is full for all the endpoints.
Hope it helps!

If you want only interfaces from WSDL just use wsimport command. Its part of jdk so no extra things needed.
run the commend: wsimport -keep wsdlUrl
it will generate all the interfaces and client code (.java as well as .class)to hit the web service. just search your interface.
Let your generated URL is :http://www.host.com/testservice?WSDL
then commend will be wsimport -keep http://www.host.com/testservice?WSDL
there are much more options with wsimport commend use as you want.
http://docs.oracle.com/javase/7/docs/technotes/tools/share/wsimport.html

ws import generate all the client side code.
asn wellm as much more things try wsimport, wsgen for more details

Related

How to create API client from wsdl file?

I have wsdl
http://www.webservicex.net/genericbarcode.asmx?WSDL .
I am trying to create a client, looking for logic in wsdl.
I think it should start from this:
BarCode barCode=new BarCode();
BarCodeSoap barCodeSoap=barCode.getBarCodeSoap();
Do I need to input any parameters there?
Executable code is generated from WSDL of the Webservice. The client then uses this code to access the Webservice.
For example, GlassFish includes vsimport utility to generate Java code from WSDL.
This utility generates a lot of compiled Java classes that allows client applications to access to Webservices. These classes are further to be added to classpath of the client.
In addition, GlassFish includes custom Ant task (also there are Maven plugin for that).
Then you need to use #WebServiceRef annotation that inject the instance of the Webservice to you client.
#WebServiceRef(wsdlLocation="...?wsdl")
private static NameOfYouServiceService nameOfYouServiceService;
...
NameOfYouService - this is convention, the name of Webservice that you develop.
Then this call nameOfYouServiceService.getNameOfYouServicePort() return you instance of the Webservice. Then you can free use methods of the instance.
Here, the name NameOfYouService - also convention.
In short, something like that.
Your Webservice is written in .NET technology, but you can also using Java client (or PHP or something else) to access it. In fact, a web service created with one technology can be accessed by clients in any other technology.
Here is a good article for your case: Java Client for WebServiceX.Net Web Service (NetBeans IDE)

Based on WSDL, how can I generate SOAP request on the fly during runtime?

I know there are some tools can help me generate the Web Services client. But, this approach does not work for me, since WSDL is dynamic in my case. So, based on WSDL, is there a Java library can help me generate SOAP request on the fly during runtime?
spring ws with the xsd you can create on fly wsdl.
The trikky part is the configuration of the soapwebservice but here you can find the 80% of the cases.
Regards

How to use WSDL url to create a request for data

I have a WSDL url(http:localhost:8080/userdata?wsdl) and I want to create a request to this webservice so I can fetch the data for further processing. Can I do this without wsimport?
If I have to create package from wsimport, how I can create a client which will use generated classes to create the XML request?
If I can do this without wsimport , how I can create a client which will create the XML request?
New to webservices, links to documentation would be appreciated. I am trying to understand this at the moment http://java.dzone.com/news/5-techniques-create-web-servic
You can use CXF wsdl2Java to generate a client code for the web service.
Once you run the wsdl2java , you will get a set of java classes generated for you. You can then use those classes to call the services without any explicit conversion of XML - the underlying framework will do it for you automatically. You can start with http://cxf.apache.org/docs/how-do-i-develop-a-client.html
I proposed CXF while you can look for many other alternatives - However, i have found CXF to be very feature rich and will help you in developing/working with web services.
On top of what Akhilesh said you can also create a Dynamic client for invoking WSDL. I have done it recently and i found it a little bit better then using CXF as dynamic client does not generate any code whatsoever. You just pass in the parameters to it and it does all the job for you. You can find a "shell" to build your own client HERE

How does a wsimport generated client work?

Before anything else, I want you to know that I can already connect to the web service server. I'm asking this question because I want to gain a deeper knowledge on how a wsimport generated client works. Based from my research, wsimport uses JAXWS. Please note that I have no knowledge from JAXWS.
I generated my client using wsimport. The WSDL I used is from an Axis2 web service and was automatically generated by Axis2. The classes below are the results of wsimport:
Under com.datamodel.xsd
DataBeanRequest.java
DataBeanResponse.java
ObjectFactory.java
package-info.java
Under com.service
MyWebService.java
MyWebServicePortType.java
MyMethod.java
MyMethodResponse.java
ObjectFactory.java
package-info.java
With the classes above, I can that tell that com.datamodel.xsd contains the beans used by the web service server (excluding ObjectFactory and package-info). Meanwhile, MyMethod and MyMethodResponse are also beans used to set the request and response parameter of the web service method/operation.
Below are my questions: (You don't really have to answer all of it if you don't know the answers on some of my questions. :) And please feel free to share any info that you think I might find useful.)
Am I correct with
Am I correct with my assumptions above?
What are the function of the other classes?
I inspected MyWebService and it contains an annotation referring to the absolute location of the WSDL I used to generate the client. What is the relevance of specifying the wsdllocation in the client? How does the client use that info?
I noticed that the actual URL of the web service is not declared in any of the classes generated. How does the client know where it needs to connect to?
Was the WSDL file annotated so that the client can read the URL on the WSDL file upon connection? If so, then does it mean that the WSDL file is always read when a new connection must be established?
Since there's a need for me to compile my application and install it on a different server, the will become invalid. Can I set it to a relative path instead of an absolute path? How? (Answer: Yes, it can be set to a relative path. The wsimport command has a wsdllocation attribute wherein the value of the wsdllocation can be specified.)
What if I need to connect to an HTTPS. How can I set the server certificate?
Is there any difference when I generate my client using wsimport and when I generate it using Axis2 or Apache CXF.
Before I answer the questions, some clarification: JAX-WS is a specification for implementing web services in Java. It describes how WSDL artifacts can be mapped to Java classes and how this mapping can be applied using annotations. You can download the specification here. The tool wsimport is part of the reference implementation of this specification and the reference implementation is part of the Java class library. There are several alternative implementations, such as Axis2, CXF or Metro, that enhance the basic JAX-WS support with support for additional standards such as WS-ReliableMessaging or WS-Security.
Now to your questions:
Am I correct with my assumptions above?
Yes, you are.
What are the function of the other classes?
The package-info exists to map the XML namespace used in the web service to the package in which your implementation classes reside. The namespace normally looks different from a Java package name (normally, it is a URL) and this makes the mapping necessary.
The ObjectFactory allows you to create any of the messages sent and received by the service. You need this if you want to hook in code in front of your stub class, provide modified messages or similar things.
I can't see the content of your classes, but if I understand it right MyWebServicePortType is an interface that resembles the portType in your WSDL. That is, it maps the operations and their signatures in the WSDL to Java methods. If you want to provide the service (which you don't, you are asking about the client), you would need to implement this interface. As you implement the client, you simply use it.
Finally, the class MyWebService contains the client stub you need if you want to invoke the web service.
I inspected MyWebService and it contains an annotation referring to
the absolute location of the WSDL I used to generate the client. What
is the relevance of specifying the wsdllocation in the client? How
does the client use that info?
The interface you generated contains the signature of the portType of the service, but it does not explain how you can talk to the service. This is part of the binding in the WSDL. The most basic setting is a document/literal style for the messages using SOAP over HTTP. Other configurations, such as SOAP over JMS, are possible and your client needs to know what protocol to use. Therefore it needs the binding WSDL. Also, as you state later, there is no endpoint address in your Java files. This address is also read from the WSDL.
I noticed that the actual URL of the web service is not declared in
any of the classes generated. How does the client know where it needs
to connect to?
It reads the address from the port of the service in the WSDL. This is located of the end of the WSDL.
Was the WSDL file annotated so that the client can read the URL on the
WSDL file upon connection?
No, the port is a typical element of a concrete web service endpoint. There's nothing special needed here.
If so, then does it mean that the WSDL file is always read when a new
connection must be established?
Well, there could be caching at the client side (I don't know about the details of the reference implementation on this one). From a conceptual point of view: yes, it is.
What if I need to connect to an HTTPS. How can I set the server
certificate
This can be tricky, I can't give you an out-of-the-box answer. I would suggest to read through questions on this topic, such as this one.
Is there any difference when I generate my client using wsimport and
when I generate it using Axis2 or Apache CXF
Yes, there is. wsimport is better, don't use wsdl2java. Here is a description, why.
You asked: I noticed that the actual URL of the web service is not declared in any of the classes generated. How does the client know where it needs to connect to?
If the WSDL was downloaded using a browser and passed as input to wsimport, then the local wsdl file location is embedded into the generated code. That is why you don't see the actual service location in the generated code. It also means if you deleted the local copy of the wsdl file the generated code will not work (when inovked using a main method) .
If the URL of the wsdl was passed as input to wsimport then that URL is embedded in the generated code, which is further used to get the actual service location. The idea is that the WSDL locations are fixed. They are expected to be in a UDDI or as a local file. This allows the actual services to move around and if they do move, you just have to modify the local copy of the wsdl file alone or update the wsdl in the UDDI. [mostly this does not happen as service locations are never IP but DNS names]
This is why it is never a good idea to publish the wsdl in the same server where your webservice is running

Mapping Requests to a Nonstandard Webservice

I'm writing a bridge between two old application on our network. One has a webservice that takes URL encoded parameters (GET) and returns an XML document. Like this:
http://mytest.com/getData/?format=xml&dateStart=2012-01-01
My question is this - I can use the XSD for the xml returned and marshall it into Java objects (xjc defined).. but is there any way to map the requests/responses to a jax-ws webservice (or similar?) It's not SOAP - so I can't go the WSDL, CXF/JAX-WS route, can I?
I was really hoping for an elegant solution to this without having to code it all from scratch (URL request , returned stream, then marshal). Is there a framework out there that would allow me configure a request? I thought WSDL supported verb="GET" but sadly, I can't seem to get it working with Apache CXF and WSDL2JAVA.
Am I totally off base here?
I think JAX-RS may be of use here. Just create XSD schemas and convert them to Java classes, and use a REST client for that site.
You can probably do it with CXF too. See here.
Check out WSGen or you can add ?WSDL to the end of your JAX-WS endpoint to get the generated WSDL. This way all you have to do is create your JAX-WS annotated classes similar to your JAX-RS ones and the WSDL is generated and it should be able to handle your XJC generated objects with no problems.
http://metro.java.net/guide/ch02.html#create-a-metro-web-services-endpoint

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