I have a general web services question and I'm hoping you can help me clear up my confusion on the subject.
I am working with a web service that the host is calling an "XML over HTTP service". They claim that this service is NOT a SOAP service, yet the response is a SOAP envelope response. The service is currently invoked via HTML form post; here is the HTML form and response:
HTML:
<FORM name=TestForm action=http://intranet/TheWSMethod enctype="text/plain" method="POST">
<TEXTAREA name=Data rows=22 cols=91 type="text" style="position: absolute; left: 78; top: 69; width:752px; height:330px"></TEXTAREA>
<INPUT type=xml>
<INPUT type=submit value="Transmit">
</FORM>
RESPONSE - SOAP Based?
<?xml version="1.0" encoding="UTF-8" ?>
<soapenv:Fault xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
<faultcode>soap-env:Server</faultcode>
<faultstring>9001</faultstring>
<faultactor>/TheWSMethod</faultactor>
<detail> ... </detail>
</soapenv:Fault>
The host tells me that there is no WSDL for this process, which is where my confusion begins.
So my question is, whether or not there is/should be an existing WSDL? (i.e. are they pulling my leg or do they not understand what I am asking) or is it possible to not have a WSDL for this type of service?
SOAP is just a specialization of XML over HTTP and that response you posted does indeed look like a SOAP response (a SOAP fault actually).
This looks like a big misunderstanding, so don't assume they are pulling your leg. Try asking your question in a different way.
As for the WSDL, if this is indeed a 100% SOAP web service, do note that it is not mandatory to have a WSDL for a SOAP web service.
A web service is just an application that exposes a set of operations over the network. In order to call these operations you need to know what their name is, what parameters they expect, what types the parameters have etc, so that you know how to build your client stub.
This means the web service needs to be documented or else you would not know how to write the code that interact with the web service. This documentation can be a Word document or a PDF and you could build the client manually from that (which involves writing a lot of plumbing code for that client stub of yours) OR the documentation could be a WSDL file which unlike a PDF or Word document can be fed to a tool to generate the stub plumbing code for you automatically.
The WSDL describes the web service - and it's good practice to provide one - but the web service exists separately from the WSDL.
WSDL is mainly a locator to the web service. You can optionally generate client classes from it using some tool to access the web service.
Related
I'm new in learning Web services.
I was trying to use soap services to get a city weather from a website.
Here is the website
http://www.bom.gov.au/australia/majorcities.shtml?ref=hdr
I want to get the weather of Broome City on Friday.
While articulating my self doing this I came across two terms: EndPoint and SOAP Action
Can anyone please help me to understand these two terms ?
Is EndPoint is the URL from where I want to get information ?
SOAP Action ? What's this, why we use this and how we can use this ?
The only thing I know about SOAP services is It sends the request in xml format to server and response also comes up in xml format.(Might be am wrong)
Thanks in Advance !! :)
If you are starting fresh on web-services, I would recommend building REST service instead of soap service. That would be easier to start with.
If you go for REST service, your url would be:
http://serverxyz.com/{city}/{day}
Coming back to your questions:
EndPoint is the URL from where I want to get information ? - Correct
One web service usually has many operations which are called soap
action/soap method. Here is sample SOAP request from w3school which is also called
SOAP envelope:
<?xml version="1.0"?>
<soap:Envelope
xmlns:soap="http://www.w3.org/2003/05/soap-envelope/"
soap:encodingStyle="http://www.w3.org/2003/05/soap-encoding">
<soap:Body>
<m:GetPrice xmlns:m="http://www.w3schools.com/prices">
<m:Item>Apples</m:Item>
</m:GetPrice>
</soap:Body>
</soap:Envelope>
I'm using the SoapUI to generate the soap request. It hints me to input the wsdl file. I do it, and it create the soap-style message. Everything is OK.
But I have a doubt. If I have webservice without any WSDL file, can I still generate the soap-style message by hand? If it can, how to?
Or if I know the webservice need to input two int paramaters and return one string value, can I speculate the soap message only by these limited information?
If you are just doing -requests- then you don't need to have the WSDL file if you know the specific service you're asking and the parameters as you say. You can even do it by hand by creating the request and then sending it over HTTP (for example you could create it with your editor in a file and then send it via wget or curl).
As for an example I'll cite wikipedia:
<?xml version="1.0"?>
<soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope">
<soap:Header>
</soap:Header>
<soap:Body>
<m:GetStockPrice xmlns:m="http://www.example.org/stock">
<m:StockName>IBM</m:StockName>
</m:GetStockPrice>
</soap:Body>
</soap:Envelope>
What you need to change is the parts in the soap:Body: of course the GetStockPrice (which is the service you're accessing) and StockName which is the parameter (in your case you may have more than one).
If in doubt you can put something to listen on a socket (for example netcat) and make your application with WSDL do a query to it and see the exact informations, then remove WSDL and work "by hand".
In Java: If you have webservice (annotated class etc.), the your server create one WSDL file when you deployed it. This WSDL you can use for soapUi.
If you have any structure (endpoint, class, XSD etc.), you can create soap message by hand.
If you weren't use WSDL for soap message, it wouldn't call/send this message. So the wsdl document is a required element according to the protocol. WSDL describes of how the service can be called, what parameters it expects, and what data structures it returns.
From Wikipedia:
WSDL is often used in combination with SOAP and an XML Schema to
provide Web services over the Internet. A client program connecting to
a Web service can read the WSDL file to determine what operations are
available on the server. Any special datatypes used are embedded in
the WSDL file in the form of XML Schema. The client can then use SOAP
to actually call one of the operations listed in the WSDL file using
for example XML over HTTP.
Here is in example for invoking web service dynamically. In this case the author doesn't know the description of the WSDL.
The purpose of the WSDL is to describe the service.
This machine-readable description allows computer programs to create clients that know how to call the service and process the responses.
We are designing a Web application which is invoked by an external system. We are going to receive a Web service from an external system which looks like this:
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:tis="http://schemas.tis.com/1.2/" xmlns:der="http://schemas.tis.com/DataProvisioning/">
<soapenv:Header>
<tis:SessionId>99999999</tis:SessionId>
</soapenv:Header>
<soapenv:Body>
<tis:Create>
<tis:MOType>SPPM#http://schemas.tis.com/DataProvisioning/</tis:MOType>
<tis:MOId>
<der:codex>12345677</der:msisdn>
</tis:MOId>
<tis:MOAttributes>
<der:createSPDD ProfileID="1" Action="createData">
<der:TechProduct Action="add" BarCode="15">
<der:Arguments ArgName="arg1" ArgType="string" ArgValue="1"></der:Arguments>
<der:Arguments ArgName="arg3" ArgType="string" ArgValue="2"></der:Arguments>
</der:TechProduct>
<der:TechProduct Action="delete" BarCode="21">
<der:Arguments ArgName="arg1" ArgType="string" ArgValue="1"></der:Arguments>
<der:Arguments ArgName="arg3" ArgType="string" ArgValue="2"></der:Arguments>
</der:TechProduct>
</der:createSPDD>
</tis:MOAttributes>
</tis:Create>
As you can see this SOAP Envelope we will receive contains namespaces in it. Up to now my Web services applications have been coded using JAX-WS and bottom-up approach (just adding #WebService and #WebMethod annotation to classes). What is the correct way to design a Web service that needs to receive a message based on namespaces ? Should I design first the WSDL ? I cannot see how to collect attributes which are in the Header or Body such as MoType or MoId. Any help ?
Thanks a lot
From your question it is tough to understand whether you want to expose a web service or you want to consume one. If you want to expose a web service with this structure and namespace you can choose bottom-up or top-down approach. Using top-down approach you will create
WSDL (here clearly you can mention the namespace for the service related details)
Schema (define the namespace for request and response elements)
Generate the Java classes from the WSDL and Schema.
Write the implementation for the Web Service interface.
If at all you want to consume the service then no need to write any WSDL. Get the WSDL and Schema(if any) from the service provider, Generate the Java classes from the WSDL and Schema received. You dont have worry about reading the values based on namespaces, the jaxws framework will do it for you.
Google the steps to consume a jaxws service.
I have the WSDL file of the remote web service I need to call from a proxy service in the WSO2 ESB and would like to know if I need to construct the soap:Body's elements manually through XSLT/Enrich or there is a way to generate the soapenv:Body's contains from the WSDL and maybe replace '?' for the values.
For example, if you've used soapUI before you'll know that when you import a WSDL file in a project a soapenv:Envelope gets generated automatically with all the XML elements and question marks for their values. Same goes for the TryIt tool in the WSO2 ESB.
Here is an example of an auto-generated soapenv:Envelope in soapUI after importing WSDL:
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:abc="http://abc.com/">
<soapenv:Header/>
<soapenv:Body>
<abc:RegisterCandidate>
<abc:NameFirst>?</abc:NameFirst>
<abc:NameMiddle>?</abc:NameMiddle>
<abc:NameLast>?</abc:NameLast>
<abc:PhoneHome>?</abc:PhoneHome>
<abc:EmailAddress>?</abc:EmailAddress>
<abc:Address1>?</abc:Address1>
<abc:Address2>?</abc:Address2>
<abc:City>?</abc:City>
<abc:State>?</abc:State>
<abc:ZipCode>?</abc:ZipCode>
<abc:Country>?</abc:Country>
</abc:RegisterCandidate>
</soapenv:Body>
</soapenv:Envelope>
Is this possible in the Proxy Service through any of the mediators available to read a WSDL and generate soapenv:Body with its XML tags (in the code above it would be abc:RegisterCandidate with its children)? I've done it with the use of the XSL templates, but it's manual and not very elegant.
I've found a few articles/blogs online about writing proxy services in the WSO2 ESB that call remote web services and what the developers were doing in there was to insert the XML elements needed in the soapenv:Body with the use of XSL templates to have the correct/full SOAP message that is then sent (send mediator) to the remote web service server.
Thank you.
There is no way to generate the soap body from the remote service's wsdl as in your requirement. But there is an easier way than using xslt. That is to use the payload factory mediator. You can define the payload and assign values using xpath as shown in the sample.
I have a web service with a client written in Java. The service works behind a firewall and if the java client wants to consume the service, then its request is blocked because the request contains links. So the request contains validator references like this:
...<S:Envelope xmlns:S="http://schemas.xmlsoap.org/wsdl/"...
Shall I fix it in the wsdl file? That is the only place which contains this link:
<definitions targetNamespace="http://mycompany.com/" name="RentalServiceService"
xmlns="http://schemas.xmlsoap.org/wsdl/" xmlns:wsp="http://www.w3.org/ns/ws-policy"
xmlns:tns="http://mycompany.com/" xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:wsp1_2="http://schemas.xmlsoap.org/ws/2004/09/policy"
xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/"
xmlns:wsam="http://www.w3.org/2007/05/addressing/metadata"
If I generate a client in .net from the wsdl file, then it does not put any link references into the request...
Thanks
Zoltan
Don't remove namespaces from the XML message. Configure your firewall instead!
Normally, SOAP is friendly with firewalls because it piggybacks on top of HTTP. If you remove the namespaces from the XML you might get it through the firewall but the web service that must make use of the message might fail to parse it because you removed the namespaces from it. XML namespaces are important because they correctly identify the domain to which each element inside the message belongs to.
Just as an observation, the <S:Envelope xmlns:S="http://schemas.xmlsoap.org/wsdl/"... is a copy paste error of some sort?... or maybe part of the problem?! The namespace for the SOAP envelope should be http://schemas.xmlsoap.org/soap/envelope/ for SOAP 1.1 or http://www.w3.org/2003/05/soap-envelope for SOAP 1.2.
That aside, if the SOAP message is correctly formatted, it should pass through the firewall. If it doesn't, then the solution is to configure the firewall properly and not mess with the SOAP message. Your network administrators should spend time understanding web services security and properly configure the firewall.
My suggestion would be to keep port 80 just for your users requests/responses from browsers and expose the service on a different port number with proper configurations. Maybe you could even set up a reverse proxy inside a DMZ to improve the web service security. With that, you won't expose your internal web service server directly to the Internet.