Remote Web Services - java

I am new to web services. I have a requirement in my project. I have to consume the web services of our vendor in my project. All he has shared with me is a WSDL file and a document about the description of the the different operations.
Question:-
1: What do I need to do consume these web services in my java project? I have been advised to use axis2, eclipse with tomcat6.
2: Do I need to ask for some other files/information from WS vendor OR wsdl file is enough to consume these web services?
3: Do I need to write a java WS client (using axis2 plugin) or another webservice which will talk to vendor web service?
Please suggest the best possible way.
I am sorry if the question sounds like a naive..

Axis is a solid choice for such application.
You need to generate an axis client based on the provided WSDL. Then you import the generated client and use it's methods. You can see the details of this process here (read whole page or starting from the linked section): http://ws.apache.org/axis2/1_0/userguide3.html#Writing_Web_Service_Clients_using_Code_Generation_with_Data_Binding_Support
You could also need some entry-point (WebService URL).
You need to generate a client, not a webservice. See point 1.

Don't use Axis if you need ambient authentication in a Windows environment. I went down that path and ended up going with Apache CXF - which seems better to me anyhow.

You can use SOAP UI to test the web service. It'll read the WSDL, let you create requests by filling in values, and display the response that you get back. It might help you get a better understanding of what the service does before you start writing your classes.

You don't need to create a new web service in order to consume a web service, you need to write a web service client.
Similar question to this one:
Steps in creating a web service using Axis2 - The client code
All the standard web frameworks have a command (normally called wsdl2java) that will read the WSDL and then generate a java based client object.
I can recommend Axis2, but another popular choice is CXF

Related

Advice on implementing JAX-WS web services to be consumed by non-Java (PHP) endpoint

I am a Java SE programmer and exploring implementing JAX-WS web services for the purpose of integrating with our web server. To this date, I have not had experience with web-services thus would like to get everyone’s expert opinion.
The background is that my company has a POS system developed and hosted in-house using Java SE. We are planning for e-commerce capabilities, which will be implemented in HTML/PHP, via external web development company and hosted externally.
Thus we are exploring implementing JAX-WS web services on our endpoint for the purpose of integrating with our e-commerce server running PHP endpoint.
I’ve done some research and my understanding is that:
it is possible to implement JAX-WS without Java EE containers
JAX-WS Web Services Without Java EE Containers
it is possible to mix end-point technologies, and specifically in my case JAX-WS as our endpoint and PHP SoapClient on our e-commerece end-point
PHP SOAP Client to consume JAX-WS with Basic Http Authentication
Using PHP SoapClient with Java JAX-WS RI (Webservice)
I am now wondering what’s is the proper approach when discussing implementation with the external web development company that is building our e-commerce platform. Most web sites and forums’ examples assumes Java on both endpoints and that both endpoints are implemented by the same developer/team.
Based on my limited understudying, I gather the process would be:
Me/my company creating the web service (coding the web services methods in Java)
Me/my company creating the server program
The wsdl generated from the URI (http://:/md5WebService?wsdl )of my server program is then used as the interface contract between our internal POS system and the external e-commerce platform
The web development company that is implementing the e-commerce platform then uses the wsdl to implement the PHP SoapClient endpoint on their side.
And in the case where our internal POS system need to consume a web services created by the external web development company, they will pass me the wsdl and I use that to make the call to them.
Is this the correct way to do proceed?
Many thanks.
Cheers,
Arthur
In Java you have actually two ways to start your design of your web service. You can either create the WSDL (Web Service Description Language) contract first (contract first approach) and then let Java or some framework tools create Java skeleton classes for you which you can use to implement the logic of each operation or you can start by code first approach and implement each web method and its logic and then let Java or some external framework tools generate the WSDL contract for you.
Either way you start, the result should be very similar and platform independent. The standard message format used for WSDL based web services is SOAP (Simple Object Access Protocol) which is based on XML (eXtensible Markup Language) which is by definition platform and programming language neutral.
So, after implementing your service and starting a server for the WS endpoint adding ?wsdl to the end of the endpoint URL should return the WSDL contract to the invoker, which can be used to create client side stubs for the required programming language which furthermore simplify the sending and receiving of messages from and to the web service. Note however that creating stub files might not be needed as all the information may be parsed from the WSDL contract directly. As of lack of knowledge concerning PHP I can't give details on how to call a WS from PHP directly or if stub file creation is required/recommended.
In order to call an other WS from your service you need to create a WS client within one of your web methods and invoke one or more of the operations offered by the remote WS and process the response within your web method.
As I am not sure if you are using any (Java) frameworks like f.e. Apache CXF I am not giving any code examples here. For integrating external web services within your service you might also have a look at Apache Camel which offers integration support for numerous Java based frameworks including CXF. Here your web service is treated as a Consumer while other external services you need to invoke are handled as Producers. The interaction between your internal and the external services is modeled here within a route where you can apply various Enterprise Integration Patterns (EIP) like splitting multiple elements contained within a response into distinct objects which you furthermore can process in parallel.
In general your enumeration of steps involved does look right if you follow the code first approach but as mentioned earlier you can also start by defining your contract first. Depending on your knowledge of the WSDL/XSD syntax (the less you know the exact syntax the more you should use code first approach), crating the contract first might enable PHP side integration sooner while you still develop the internal logic of your implementation.
it is possible to mix end-point technologies, and specifically in my case JAX-WS as our endpoint and PHP SoapClient on our e-commerece end-point PHP SOAP Client to consume JAX-WS with Basic Http Authentication Using PHP SoapClient with Java JAX-WS RI (Webservice)
This is the exact purpose of introducing webservice concept. You don't have to worry about on which platform or language your client and server is implemented. Client and server will simply exchange xml messages (platform independent) as agreed upon within wsdl.
Go ahead with your understanding.

Consume .NET web services in Java

I have created .NET web services. I want to run it on a remote server and have the Java Applications (clients) contact the server for data. How should I implement the Server such that the Clients can make use of the org.apache.xmlrpc.client.XmlRpcClient package?
I just want the clients to generate a request for data and does not want to have any other dependencies.
Here is a good material on using eclipse for this purpose: http://wso2.org/library/tutorials/creating-web-service-client-3-steps-using-eclipse
Thanks.
Although both are rightfully called "web services" the SOAP based web services usually created in .net are incompatible with web services following the older XML-RPC standard.
In my opinion you can follow 2 routes to solve your problem:
either you go the SOAP route under Java, one of the most common API's for that purpose would be jax-ws - some excellent pointers to tutorials here, in Pascal Thivent's answer
or you transform your .net webservices to XMl-RPC by using xml-rpc.net
Both routes have advantages and disadvantages, it's hard to make that choice for you without knowing more about your project. A priori choosing the SOAP route might look "safer" as there the entire communication will be based on standard components.
If you have the Web Services on the .NET side, you must have a Web Service Description Language (WSDL) (if you are not talking about REST), you can easily create the client classes to consume this Web Service using an IDE, check this link here: http://netbeans.org/kb/docs/websvc/client.html
If you are using Eclipse I suggest you this tutorial to build a simple WS client.
You can adapt this example application to your real needs.
NOTE the example uses an old version of Eclipse, but the wizard is very similar also in newer versions.

Simple web services in Java applications

I am new to web service and WSDL. I have a MySQL database stored in a server and I need to create a very simple web service that allows third party Java applications to input an integer (say 'membership number') and receive a string (say 'member name'). This should be done with WSDL.
Can someone please tell me what files do I need? A WSDL file, a schema file? Do I need a Java class stored in the server responsible to communicate with the database?
I am pretty lost, I would be thankful if you could give me some suggestion
As the simplest form of webservice is you can continue with JAX-WS, upon deployment of appilication it will publish a WSDL file and you can use this WSDL to communicate it from client
JAX-WS is the simplest way to convert an existing method into a web service endpoint, with a few annotations, and the simple web server in the standard Java 6 JRE. It can autogenerate the WSDL too.
This tutorial covers the essentials for getting started: http://java.dzone.com/articles/jax-ws-hello-world
I have found this to be a very robust technology.
Using the SOAP Webservices can get pretty messy. Unless you are forced, I would recommend you use REST for webservices, it is much less complex than SOAP. You can find a good REST tutorial here.
If on the other hand you must use SOAP, you could strat by taking a look here.

What is purpose of CXF or Spring WS

I am new to consuming web services. I am trying to consume a SOAP service. This is currently in the test environment. What I have done is
Use wsdl2java to generate a wsdl that I have copied to my domain folder.
Use the API to send requests and receive responses.
What concerns me is do I need CXF or Spring WS to wire the service or is what I have sufficient. I am asking this because I have seen elsewhere like
What I don't get is where I would generate property when environments are switching from development to QA to production. And do I need to use CXF or Spring WS or are the annotated classes (#WebServiceClient sufficient) to consume the SOAP service. Basically, how to connect to different endpoints.
I apologize if this is rudimentary question. Thanks.
Spring-WS and Apache CXF are primarily useful for creating web-services. They are alternative web service implementations to the one that ships with Java6.
You can use them for writing clients, but there's not really much point, unless you're really keen on the alternative API that those provide.
The standard JAX-WS artifacts generated by wsdl2java should be perfectly sufficient for what you need.
As for your second question regarding how to target different prod/QA endpoints, you should ask a separate question for that, with full examples of what you have.

How To Use WSDL Url

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.

Categories