I've seen this problem all over the Web, but still haven't found a clear solution that has worked for me. Here's the issue:
I am trying to create a Web service client in Java. The client needs to be a console app that will be placed on a server and automatically run at a certain time interval. The Web service I am trying to consume was written and is hosted by a third party company. The service was written in ASP.NET. The company in question has several services that we hit. All of them are written in ASP.NET. I have never dealt with these services until 2 days ago when I was tasked with consuming 2 of the services and building an Excel spreadsheet from the data. Before I continue, let me describe my development environment. Some of this is relevant, some is not, but I want to include everything:
Windows 7 Professional 32-bit
NetBeans IDE 6.9.1
Java JDK 1.6.0_17
jre6
Glassfish 3 Open Source Full-Platform Release
All software has had all available updates applied
On to the problem. When I added the first Web Service Client to my console app, I was surprised at how smoothly the process went. Most of my experience writing Web Service apps is in .NET. I was able to import the WSDL and NetBeans generated all classes on the first try. Within 5 minutes, I was able to make my first call to the service and was greeted with the expected response, letting me know that my attempt was successful. I then added the second Web Service Client to the console app using the address to the second WSDL I needed. This is where I ran into a major problem.
Upon importing the WSDL, I was alerted to an error by NetBeans stating:
Web Service Client can not be created by JAXWS:wsimport utility.
Reason: undefined element declaration 's:schema'
After abusing Google for the next hour looking for a solution, I finally decided to apply some trial and error. Looking at the Output window in NetBeans, I could see that it was complaining about 3 specific lines. Once I took a look at the WSDL, I could see that those 3 lines were exactly the same, as follows:
<s:element ref="s:schema" />
These 3 lines were found in random places from the top of the WSDL, down to about half-way through. I removed these lines from the WSDL found in the Web Service References folder, leaving the WSDL in the META-INF folder alone. I then did a refresh on the service reference and much to my surprise, NetBeans parsed the WSDL and generated my classes just as before. Great, right? Well, here's where problem #2 comes into play.
Now that I was able to compile my app with no errors, I had to try to hit the service to see if my hack had worked. It did not. Because of another bug in JAXWS, I have to provide the URL to the WSDL in the constructor when creating a service object. This means that the WSDL I fixed is being ignored and the service is now back to using the WSDL that can not be parsed. When I tried to provide the location of WSDL I edited locally within my project, I was greeted with another compilation error stating that I had a NullPointerException. It said that I needed to initialize the object before using it.
I have researched what seems like an infinite amount of topics on this site looking for and trying any solutions that have been provided. I have also tried solutions from all over the Web, all with no luck. If anyone has any advice for me, any tips, tricks, hacks, please let me know. I'm open to any suggestions at this point.
Thanks in advance for any assistance provided.
One-sided contract changes may lead to problems.
Assuming the s prefix refers to the http://www.w3.org/2001/XMLSchema namespace, it looks like your WSDL references XML schema types. JAX-WS is probably unable to resolve this when generating the JAXB bindings.
You can download the XSD from http://www.w3.org/2001/XMLSchema.html; at a minimum, you'll need XMLSchema.xsd, XMLSchema.dtd and datatypes.dtd. Generating Java types from this may require fiddling with your JAXB binding configuration.
Alternatively, it may be easier to just use dynamic JAX-WS client code. You can use a tool like soapUI to create/test sample XML requests.
If you do decide to edit the WSDL, the generated service code should have a constructor of the form Foo_Service(URL, QName) that allows you to provision the WSDL locally (e.g. from your classpath).
The first thing I'd do is try to open it in one of the tools meant for testing SOAP services, like SoapUI. If you have schema not resolving, that is possible there will be pieces of code that you may need that won't be generated as well. I had that happen recently with a vendor supplied "web service", and after much dissembling they "miraculously" found an alternative set of services that worked fine.
You could also try some of the alternatives to Jax-Ws, like CXF or Axis.
Related
I inherited a codebase, a chunk of which is a webservice built using the Eclipse generators. The generated code appears to have numerous file paths (for wsdls, etc) which refer to locations on the original developer's box. For example, in a service class's static constructor:
url = new URL(baseUrl, "file:/C:/Users/OldDeveloperName/workspace/ServiceProject/WebContent/WEB-INF/edmo/AXIS-1-4/MainEntityService-1.0.wsdl");
Seems like a bad thing, to my naive eyes. Is this a) OK, or b) fixable? I know I could just edit it now, but there's quite a few service files and it seems like there'd be an easy correction if it's a common problem. I mean, as-is it doesn't even look deployable to me.
Original developer obviously followed the approach to store WSDL locally, which is actually a good practice. Namely, JAX-WS client before execution needs to retrieve WSDL once more from the original location to check additional metadata etc. (it sounds weird, but that's how it works). But, what if original WSDL is not available anymore or the Web service developer updated the WSDL with e.g. new method? Your Web service call would not be executed and that is not probably what you want. Therefore, people started to store WSDL together with their client, to avoid vulnerability on WSDL availability/change.
Is this a) OK, or b) fixable?
It is not OK to store WSDL on local filesystem, and that is where the original developer made the huge mistake. WSDL should be packed together with Web service client (in same JAR) and retrieved directly from the archive. There are several ways how to retrieve WSDL locally, see this tutorial for instructions. One way or another, you will have either edit the WSDL location or completely change the old code :)
References:
Why does JAX-WS clients need WSDL access?
We have some existing Java code running on a Tomcat server that we want to allow code on another machine to execute, so we are looking into web services. I am new to web services and I think I'm probably doing something wrong here.
I have followed a few online tutorials on how to deploy a JAX-WS web service in Tomcat. I have created a web service class and annotated it with #WebService, written a web.xml and sun-jaxws.xml file, packaged those files (plus the JAX-WS jar files) into a .war file, and deployed it into Tomcat. That appears to be working, as I can load the WSDL file in a browser pointed at Tomcat.
It's the web service client I'm having trouble with. First of all, there are existing classes on the server side that get mapped into a database. We want to allow the client to use those same existing classes and create instances of out of them, invoke the web service, and then have the objects get stored into the database. However, when I ran the wsimport command against the server's WSDL file, it generated a bunch of Java classes, a lot of which are similar to our existing classes. I guess we have to use those instead of our existing classes? So much for code reuse, unless I'm confused, which is very possible.
So now I've written the client using those classes that wsimport generated. But I'm getting compile errors. Some of the fields in our existing Java classes are of type java.net.InetAddress. But for some reason, wsimport generated its own InetAddress class, and this is what it looks like:
package ems.server.webservices;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlType;
#XmlAccessorType(XmlAccessType.FIELD)
#XmlType(name = "inetAddress")
public class InetAddress {
}
Yeah it's just a class with nothing in it! So a lot of the compile errors I'm getting say:
WSClient.java:37: setAddress(ems.server.webservices.InetAddress) in ems.server.webservices.NetworkAddress cannot be applied to (java.net.InetAddress)
networkAddress.setAddress(InetAddress.getByName("1.1.1.1"));
I'm trying to create a java.net.InetAddress, but it wants me to use the empty class that was generated by wsimport. I must be doing something wrong here. Please enlighten me.
We have some existing Java code running on a Tomcat server that we
want to allow code on another machine to execute, so we are looking
into web services
Web services for this? Why?
First of all, there are existing classes on the server side that get
mapped into a database. We want to allow the client to use those same
existing classes....So much for code reuse
Really bad idea. The purpose of Web Services is not code-reusability but interoperability. Trying to reuse business classes that actually carry the semantics of the programing language you are using, is not only a bad practice but can lead you to many issues unless for most trivial web services where you also control the client.
when I ran the wsimport command against the server's WSDL file, it
generated a bunch of Java classes
When you run the wsimport all the necessary artifacts required for the web service client to communicate to the web server are created. This includes all the stub classes that help in transforming your classes during the SOAP marshalling/demarshalling
But I'm getting compile errors. Some of the fields in our existing
Java classes are of type java.net.InetAddress
java.net.InetAddress is a Java specific class. You should not be exposing that in the first place. That is why the code generator creates the empty java.net.InetAddress.
To be honest I can not give you a direct answer for making this work. The only I hint could give you is that if you annotate the InetAddress fields with #XmlTransient they will not be exposed in WSDL and you will not have that problem. Of course, you don't say if this field is needed for you so, perhaps my suggestion is useless to you.
But my recomendation is to switch your approach. You are on the wrong path IMHO.
The only recomendation is to change your approach.
I've inherited the code base for a Java application which talks to a few SOAP web services. Proxy classes to do this are generated using an ANT task calling wsdl2java. As my Java experience is quite limited, I'm still trying to get my head around exactly how this all works.
There is a build-wsdl2java.xml file in the project that seems to contain the configuration information required for the class generation. The file as it stands currently has attributes that aren't currently supported (namespacesmapfile, overWriteTypes, testcaseoverwrite), but if I attempt to resolve this by changing the first to 'namespacemappingfile' and removing the others, the attributes revert back if the project is cleaned. The URL for the WSDL also reverts back if it is changed.
What controls the generation of this file, and where do I define the configuration parameters that it contains?
Finally found out what was controlling this and, more importantly, have got things compiling again. I'm using JBuilder 2008 (an Eclipse based Java IDE from Embarcadero Technologies), and it would appear the client proxy classes were generated from the WSDL by using JBuilders built in support for this, which is effectively a wrapper for wsdl2java as mentioned by Noergaarde.
In order to set settings such as the URL for the WSDL, I had to switch to the Modeling perspective, and use the Model Navigator to change the URL, by selecting the class under the Web Service Client node and using the Properties view.
When you do a build of your project, does the timestamp of build-wsdl2java.xml change? ie. is this file generated by the build in another ant file?
At any rate, it certainly sounds like your client stubs are generated using AXIS.
http://ws.apache.org/axis/java/user-guide.html#WSDL2JavaBuildingStubsSkeletonsAndDataTypesFromWSDL
I have a public EJB class that I want accessible online as a web service. I have generated a WSDL and the SOAP mesasging seems to work. I used soapUI to test the connection. What I'm not clear about is how would I then use this exposed web service. I'd like to try another language like Python to then make calls through that interface. I know that the WSDL is supposed to help a potential client build it's client side code but I'm not sure about how to specify the connection and location and login information if I had that. I know I'm asking a large topic but any information would help. Thanks
Edit: so basicaly I'm just wondering do I have to use tools to generate my client code from the WSDL like axis2. Or whatever Python uses. Or can I write the code by hand? What's generally done. is the server reference included in that WSDL and are call methods generated usually?
Take a look at ZSI
But ZSI is too complex and spends more time to generate proxies
I suggest you to use suds. suds generates the proxies On the fly and so fast, i used it in some projects.
another packages are available:
soaplib
SOAPy
pysimplesoap
We've written a WCF service to be used by a Java shop, who is using CXF to generate the adapters. We're not that familiar with Java, but have exposed the service using basicHttpBinding, SSL, and basic authentication. Integration tests show that a .NET client can consume the service just fine. However, the Java shop is having trouble consuming the service. Specifically, they getthe following JAXB error: Two declarations cause a collision in the ObjectFactory class. This is usually caused if 2 operations have the same name and namespace when CXF attempts to create adapter classes.
We can't find any type or operation names that should cause any sort of collision. We have made sure that all custom types specify a namespace, and tempuri.org is not specified anywhere in the WSDL. The Java shop suspects the error is because the generated WSDL contains <xsd:import elements.
So, my questions:
Is there any better way than CXF for the Java shop consume the WCF service? Project Tango looks interesting, but I don't know enough to tell them to consider using it. Is CXF a defacto standard in Java?
BasicHttpBinding/SSL/Basic Auth are MS recommended for interop scenarios, but the client still seems to have interop problems. Should we consider other bindings or settings to make this easier to consume?
Is there a way to configure WCF to always output a single WDSL with no schema imports?
The "Two declarations cause a collision in the ObjectFactory class" error message usually has nothing to do with imports. That's a JAXB error message that is usually caused by having multiple elements or similar that cause the generated field names to be the same. For example, if you have elements like:
<element name="Foo" .../>
and
<element name="foo" .../>
That can cause that error. Another is using thing like hyphens and underscores and such that are usually eliminated+capped:
<element name="doFoo" .../>
and
<element name="do_foo" .../>
With 2.1.4, you can TRY running the wsdl2java with the -autoNameResolution flag. That SOMETIMES helps with this, but not always. Unfortunately, the information that JAXB gives in these cases is nearly worthless and lots of times it's just trial and error to find the conflicting types. :-(
I am deep into Java & WCF interoperability. As someone else said you need to flatten your WSDL if you are working with file based WSDL. However I use Netbeans 6.5 and if you point to a real url like http://myservice/?wsdl , Netbeans can cope easily with the default wsdl generated by WCF.
In real life other things you need to consider is service versioning, optional datamembers (doesn't go well in java, so I suggest to make all datamembers IsRequired=true), order etc.
The real tough thing to get going was security. I had to make mutual certificate authentication working and it still has some issues.
The only way for your java client to talk to a WCF component will be one of the HTTP methods - basicHttpBinding, ws*, etc just as MS recommends. Java can't talk to WCF over TCP or namedPipes or MSMQ, etc.
I'd start with a super simple WCF component - something with a single method that spits out a string. Get that working with Java and then work your way up. Make sure that everything you're exposing is working with base types or well defined [DataContract] objects.
I've developped WCF with Axis2 clients. The authentication methods I've sucessfully uses is BasicHttpBinding/SSL/Basic (Transport) and WS-Security with Username (and MTOM).
The Metro implementation is used by SUN and Microsoft to test the interop :
http://weblogs.java.net/blog/haroldcarr/archive/2007/11/metro_web_servi.html
Sorry no clue about the import generated by WCF for the schema definition.
The problem with xsd:import is very common. Some toolkits or runtimes cannot cope with that. To address this, you can flatten the WSDL that is generated by WCF.
Check this post.
Regarding whether CXF is the right Java stack - I have never heard of it? I have used AXIS successfully, as well as JAX-WS. Both have been pretty straightforward.
This is a Jaxb issue. I ran into the same issue but used the xmlbeans option instead in wsdl2java client generation. To be honest I seem to prefer the xmlbeans objects more over jaxb as far a consumer to this webservice.