So I have a simple xml-rpc server (xml over http) provided to me to use. But the thing is, the server is not equipped with wsdl. I don't have access to the server code, so I don't know about their implementation of it
How can I develop an xml-rpc client in Java, with no wsdl provided, without using 3rd party library like the Apache xml-rpc client?
Please help.
The wsdl is only really useful with a 3rd party library, because it helps you generate objects that can be serialized to xml without hand-coding the xml.
If you don't have the wsdl, you must either hand-code each xml message you send and hand-parse each message you receive, or create a set of objects on your own and serialize and deserialize them appropriately.
Wsdl file will only help out, without that you'll be unable to generate client and neither you can test your application. Even if you have connectivity to server.
Related
I am currently working on a Java SOAP client that consumes the SOAP Web Services from a large ecommerce provider (Magento). On that server, I want to be able to talk to multiple instances (in this case stores). Now normally, one would get the WSDL file and generate the classes with it. However, on that server, each instance has its own WSDL file that may or may not be identical in structure. What is the strategy for me as the client. Should I generate Java classes for each WSDL file? Would that give me too many packages? Are these packages permanent or temporary for a request? Should I forego creating classes and just use the harder approach: some SOAP Client (any recommendations?) along with HttpUrlConnection?
Go through this
You need to create the object (http://magentohost/api/V2_soap?wsdl=1) once and this will have all the information required for the webservices and its structure as well.
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
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.
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.
Im a little confused on the varying definitions and implementations of web services available as implementations. Need some clarification please.
Ones I have used till now:
If a vendor gives me a specific format of XML that I can send populated with data to request and I make a simple HTTP POST over the internet passing in the XML String as the payload, is this a web service call ? If so, is there a specific name to it, this kind of web service ? Because obviously, it does not use anything like Axis, WSDL or SOAP to establish this connection.
A variant of this is If the vendor gives me an XSD, I use JAXB to make a java class out of it and pass in the serialized version of the object, which eventually works out to be the same as option 1.
RESTful web service: Vendor gives me a URL like http://restfulservice/products and I can make HTTP Requests to the URL and depending on what HTTP verb I use, the appropropriate action is called and the response sent over the wire.
Ones I have only read about\ have a vague idea about
SOAP. How does this work?.. Ive read the W3Schools tutorial and I undertsand that there is a very specific form of XML that is standardized according to W3C standards that we use to pass the same kind of messages as we did in option 1. But how does this work in real life? Vendor sends me what? Do I generate classes? Do I serialize some objects and http post them over to an address? Or do the generated objects themselves have connection methods that will do them for me?
What about WSDL? When does a vendor send me WSDL and what do I do with it ? I guess I can generate classes from it. If yes, then what do I do with the generated classes ?
When do I need that axis jar to generate classes from something that the vendor sends ?
As you can see, I have some clear and other mostly vague ideas about the different kinds of web services available. would help if someone ould clarify and\or point to more real-world resources. I've looked a little bit into Java Web Services on the internet and the numerous four letter acronyms that get thrown at me make me dizzy.
Thanks
If a vendor gives me a specific format
of XML that I can send populated with
data to request and I make a simple
HTTP POST over the internet passing in
the XML String as the payload, is this
a web service call ? If so, is there a
specific name to it, this kind of web
service ?
This is still a web service, yes. It doesn't have an "official" name, I usually refer to it as XML-over-HTTP, mainly because I can't think of a better name.
SOAP. How does this work?.. Ive read
the W3Schools tutorial and I
undertsand that there is a very
specific form of XML that is
standardized according to W3C
standards that we use to pass the same
kind of messages as we did in option 1
SOAP provides a standard wrapper layer around the sort of messages you were sending in (1). This wrapper provides information such as an indication as to which operation you are invoking. It can also provide security services, transaction information, and so on. It's a pretty thin layer, usually.
What about WSDL? When does a vendor
send me WSDL and what do I do with it
? I guess I can generate classes from
it. If yes, then what do I do with the
generated classes ?
Again, WSDL is a pretty thin layer, this time around an XML Schema. It defines the operations that SOAP messages will invoke at runtime, as well as the Schema types of the requests and responses. Its a way of formalising the XML document exchange interface.
Say, for example, you had an XML Schema, and have a web service as you described
Using JAXB to generate java source from the schema
Send XML documents conforming to that schema over HTTP to the web service
With WSDL and SOAP, you would extend this a bit :
Write a thin WSDL wrapper around the XML Schema, formalising which operations are available.
Use a WSDL import tool to generate client/server stubs for that WSDL/Schema. In Java, this often incorporates JAXB.
Use a SOAP client/server to invoke the web service
As you can see, it's essentially the same process. The difference is that SOAP/WSDL provides additional information and context to the tools, allowing those tools to do more of the work for you. It's not hugely different, though.
If you get a WSDL document from somewhere, all you really need to know is that it defines a service interface. You run it through your favourite language's binding generator to make some code that you can use to call the service. Typically that means you'll be talking over the wire to the service using SOAP messages over HTTP. SOAP's just a wrapper round sending pretty arbitrary XML messages.
Axis is a library for doing this stuff in Java (both client and server side). I suspect that there are better implementations in other libraries.