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)
Related
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
I have just a .net wsdl file and I want to connect to it using java to test some functionalities.
But the problem is that I have just access to .Net server in production environment! and I can not connect to it at work!!!
I'm thinking of a way to reverse engineer the wsdl file and generate java class from that, then I can create another web service in java that is exactly like .Net web service and run my program and test it using java.
Do you know any tool or command to reverse engineer a .net web service to java class?
I've heard of SOAPUI, does that have such a feature?
EDIT :
By the way I'm using jax-ws (the reference implementation of java webservice)
Well, what you can do is:
1) create a Maven project
2) add the cxf-codegen-plugin to the pom.xml file
3) the plugin generates a Java interface, along with classes needed for SOAP communication
4) create a class which implements the interface (provided you know the logic behind each method)
5) you now have a web-service in Java which does the same thing as the .net counterpart
6) deploy to an app server like Glassfish/Tomcat/etc
5) ???
6) profit
An appropriately written web service shouldn't care what language the client or server is written in to perform its function. Just point a utility such as wscompile at the wsdl and given the right parameter combination it will generate class stubs for you.
I wrote a java web service on Netbeans 6.9.1 and deployed on GlassFish 3.0.1
I have a wsdl url like this "http://localhost:8080/web2/service2Service?wsdl".
How can I use this url to access this web service from another java application.
Thanks
You need to generate some Java that represents the client's view of the Web Service and then invoke that Java. Here's an article which explains some of the detail.
Generating client from WSDL in Eclipse
The general idea is that you generate some Java classes from the WSDL. Those classes act as a proxy for the service you want to call. Your java invokes methods on the proxy objects, the generated code creates the appropriate SOAP messages, sends the HTTP request, interprets the response and your code just sees a Java result.
I just use the tooling built into Eclipse, but you will also find other suitable generators, for example in Apache's Axis
1º U must save the content in a "myWebServices.wsdl" file
2º Run your Wsdl converter, all compilers have one of this, normally the name is WDSL.EXE
This process will create a new file with NameSpace or Package with the definitions of webservices built in.
3º Then imports this package or built a library.
Develop web service Client in second application.
You can use Netbeans to create web service client by giving your wsdl url
The document at this url is the actual wsdl (a description of the actual webservice, written in WebService Definfition Language).
The description includes information about the services url, the protocol(s), the method names and and data objects. Your application will use that information to call the remote methods of that service.
The protocol may or may not be SOAP, and without knowing the webservice details, it's quite impossible to recommend a toolset or methodology to use the webservice, there is no general approach. In most cases we see SOAP, for those services I recomment soapUI as a general tool to use and test SOAP based webservices and apache axis to implement java based service consumers.
In most tutorials that I have seen so far people are using wsconsume or something like that to create classes that clients can use to access an EJB 3 Web Service.
Is this the only possible option? As my EJB's interface is annotated with WebMethod, WebParam, etc. isn't it possible to create a dynamic proxy or use runtime bytecode enhancement to create the proxies, etc. on the fly? E.g.:
MyWebService webService = WebServiceEnhance.getWebService(MyWebService.class);
webService.webMethod("foo");
A link to good reference material is also highly appreciated.
One way is to deal with pure XML request/response. You can trap sample request/response for the web service you want to consume using either SoapUI or Fiddler and then use these samples as templates within your client.
I used Axis2 to create a web services. And it was very easy to write, test and run it.
But now I have existing Java Web App running under Tomcat and I want to add Web Services to it. E.g. instead to process POST and GET parameters and generate HTML I want to receive SOAP messages, to process it and to return response as SOAP message again.
Which technology/framework/library/etc. should use?
Preferably should be easy as writing Web Services for Axis2.
One possible workflow is:
Refactor your web app so that the business logic is implemented in separate methods, and doPost() and doGet() only call these methods.
Extract an interface of your business methods from the web app class.
Run java2wsdl to convert the above interface and its related types into a WSDL spec.
Run wsdl2java with server-side bindings to generate the skeleton class and other auxiliaries.
Replace the skeleton class with the original web app class (or copy the relevant methods from the web app to the skeleton class).
Remove the redundant doPost() and doGet() methods, delete the old web app.
Et voila! You have an Axis2/Tomcat web service. It requires some refactoring, but no change to the core logic.
Add the #WebService annotation to your java class.
add #WebMethod to the methods you want to expose as web-service operations.
Add the framework specific servlet and filter mapping in the web.xml file. For example, for the Sun RI f/w it is WSServlet. There must be something similar for Axis too.
Write a WSDL file, or generate it from the Java class you have. You can use a tool like wsgen [works for Sun RI]. it's java2wsdl for Axis.
Add the required web descriptor file. It's usually a wsdd file for Axis and the sun-jaxws.xml file, in case of Sun RI.
If you want add a new web service you can add that to the existing web app using Axis 2
If you want to use an existing feature(functionality), first you need to refactor your web app and extract the business logic in to new methods. Then annotate the class and interface with #WebService. If you want to hide some methods which expose in web service, then annotate those methods with #WebMethod(exclude=true)