I have a big problem in Axis2 client implementation.
I've generated the source code of my client (Java) through the Intellij Idea IDE from a wsdl file.
I use the client to connect in https with a webserver using a smartcard, in which is stored the certificate for the authentication.
Using the first smartcard, everything works fine: I receive data from the webservice in the right way. Using the second smartcard, I receive data related to first smartcard owner.
Analyzing the logs of my application, I've noticed that, at the end of the first communication, a session has been saved. So, in the second connection, the authentication is not needed and data is related to first smartcard owner.
Googling around, I've found that, to avoid to maintain sessions in Axis2 clients, it is needed to set the following:
currentStub._getServiceClient().getOptions().setManageSession(false);
But it does not work properly.
Anyone has suggestions?
I know, this question is quite old.
You could just create a new Stub. This should not have any reference to the old connections/sessions.
Related
I was asked this question in a technical interview for a integration intern role.
He was digging much into understanding of SOAP web services.
Question). Consider that you are exposing a web service through SOAP to a Client.
The url through which you are providing the service is up and running when you check it.
But the Client has a problem, he is not able to access your webservice.
How will you go on troubleshooting this issue?
My response:
I would first check whether the url the client is trying to access the service is correct.
Will check the .wsdl file: port, bindings & will check once whether upon sending a SOAP request to the URL, am I receiving the SOAP response in local through SOAP UI.
If I get error, will troubleshoot based on the kind of error I get: Like page not found, null exception etc.
I felt he was still expecting some other point. He hinted saying where in what registry you will check all the web services which have been hosted(I guess this was much of a production support issue :P)
I told I may look into UDDI registry, but was not sure with this.
Please let me know your inputs on what could be possibly a right approach?
Apache jUDDI PMC here. Yes UDDI could be used to verify that the client is pointed at the right location, assuming the client knows where the UDDI server and that it is registered and the client knows what to query for on the UDDI server and a UDDI query is part of that client's normal workflow. That's a lot of assumptions but certainly feasible.
Most of time, the endpoint is in a config file somewhere or some idiot hard coded it.
That said, this my go to list for checking SOAP service connectivity (from the client's perspective)
DNS resolution of the hostname in the URL
Ping the remote host
HTTP GET to the URL of the SOAP service + ?wsdl (this usually works). This is also a good time to verify SSL connectivity.
You can also parse the WSDL doc, assuming one is returned for identify the endpoint url.
Finally if that all works, execute the service. HTTP 200 is general a positive sign
Edit:
Another alternative approach is to implement a very simple API (wsdl method) on every SOAP service that simple returns a true/false that answers the question "Am I open for business?". This method would provide a standardized approach for identifying if a service was available or not by testing an external dependencies (databases and whatnot).
I have a SOAP webserver developed in Delphi XE2 that exposes some methods and it uses SSL. I built my client also in Delphi XE2, and I use THTTPRIO to connect to webserver. My question is related to the use of SSL certificatest with THTTPRIO. If I call my webservice it works without having a certificate installed, but I think that it shouldn't.
Second scenario :I have a self signed certificate which I installed it and after I made a call to my webservice it works also.
When I inspected my events: HTTPRIOAfterExecute and HTTPRIOBeforeExecute, I converted SoapRequest and SOAPResponse to string from TStream and seems that it isn't encrypted in both cases. I also found on another forum the same question but with no response.
I searched for info about SOAP SSL Clients with Delphi but couldn't find any new info. Could any of you guys give me some advices regarding this issue?
If I call my webservice it works without having a certificate
installed, but I think that it shouldn't.
Not many web services require client certificates (with exceptions like banking and other high risk environments). It is more common that clients want to verify the server identity, and this is done with server certificates.
So I would say this web service does work in a normal, expected way.
HTTPRIOAfterExecute and HTTPRIOBeforeExecute, I converted SoapRequest
and SOAPResponse to string from TStream and seems that it isn't
encrypted in both cases
This is correct, the message payload will appear unencrypted because SSL / TLS does encryption on the transport layer. Your application will not see the encrypted data, which actually makes things easier.
You can add encryption for the message payload, there are generic libraries for this (however I have no experience with using encryption HTTPRio).
I am new to RESTful webservice. Whatever I have read over the internet about RESTful webservice, I came to know that REST works similar to servlet + webservice.
Our traditional webservice looks like JSP-> Servlet -> Service -> DAO -> Database.
Will REST replace Servlet in this heirarchy?
My ultimate goal is that my web application should support mobile application and normal browser also. Is it good idea to use REST in that case. If not, in what situation we should use REST?
I hope my question is clear.
Please help me.
Thanks in advance.
There are many ways we can achieve Machine to Machine communication.
Web services also helps communicating between applications made in different platforms.
For example a .net GUI can call a java server side program for data.
REST is one of that kind, based on HTTP protocol.
SOAP web service is heavy weight (using lots of XML) where as REST is simple and you can expose any of your APIS simply using REST.
A services exposed as REST services can be invoked by a client using on of the HTTP verbs GET, POST, PUT, and DELETE with their meaning same as in HTTP.
RESTful Web Services expose the state of its resources.
An 'Employee' data can be queried and represented in any format (Json, XML ...) using REST.
Rest won't replace the Servlet in your hierarchy, actually the HTTP based REST methods are written on this servlets.
Please go through this URL : http://docs.oracle.com/javaee/6/tutorial/doc/gijqy.html
Using REST is not related to browser experience on mobile or other devices. It totally depends on the client side technology used and your browser compatibility with those technologies.
Using REST is a good idea to access data at client side using simple AJAX calls.
REST means Representational State Transfer. It is a way of thinking about architecting network communication between client and server, with the focus being on transferring a resource from server to client and back again.
To understand the significance of this first consider a different architecture, Remote Procedure Call. This is where the client calls a function on the server as if the function existed on the client.
So you want to edit a photo that exists on the server. Your client is a photo editing app that uses RPC to achieve this. You want to blur the photo so your client calls the blur() function using RPC, and the server blurs the image and sends back the updated image. Then you want to rotate the image, so your client calls the rotate() function and the server rotates the image and sends the rotated image to your client.
You might have noticed two issues. Firstly, every time you carry out an action on the photo the server needs to do some work and send you back the updated image. This uses a lot of bandwidth.
Secondly what happens if tomorrow the server developers (who might be nothing to do with the client developers) decide that rotate() is the wrong function name, it should really be rotate_image(), and they update the server. Your client continues to call rotate() but this now fails because such a function doesn't exist on the client.
REST is an alternative way of thinking about client/server communication. Instead of telling the server to carry out an action on the resource (eg rotate the photo), why doesn't the client not just get a representation of the resource and carry out all the actions it wants to (blur, rotate etc) and then send the new state of the resource back to the server.
If you did it this way the protocol to communicate between client and server can be kept very simple and will require very few updates. All you need is functions for the client to get the resource and functions to put it back on the server. The client will have to know how to blur the image and rotate the image, but it doesn't need to know how to tell the server to do this, it just needs a way of telling the server to save the updated image.
This means that the developers of the client can work away implementing new features independently to the developers of the server. Very handy if the developers of the client are nothing to do with the server (the developers of Firefox have nothing to do with the New York Times website and vice versa)
HTTP is one such protocol that follows this architecture pattern and it allows the web to grow as it has. There are a small set of verbs (functions) in HTTP and they are concerned only with transferring a representation of the resource back and forth between client and server.
Using HTTP your photo client simply sends a GET message to the server to get the photo. The client can then do everything it wants to to the photo. When it is finished it sends the PUT message with the updated photo to the server.
Because there are not domain specific actions in the protocol (blur, rotate, resize) this protocol can also be used for any number of resources. HTTP doesn't care if the resource is a HTML document, a WAV file, a Javascript script, a PNG image. The client obviously cares because it needs to understand the resource it gets, and the server might care as well. But the protocol between the client and server doesn't need to care. The only thing HTTP knows is that there is a variable Content-Type in the HTTP header where the server can tell the client what type of resource this is.
This is powerful because it means you can update your client independently to updating your server without updating the transfer protocol. HTTP hasn't been updated in years. HTML on the other hand is updated constantly, and web servers and web browser are updated constantly (Chrome is on version 33). These updates can happen independently to each other because HTTP never (rarely) changes.
A web browser from 10 years ago can still communicate with a modern web server over HTTP to get a resource. The browser might not understand the resource, say it gets a WebM video that it can't understand, but it can still get this resource without the network communication failing.
Contrast that with the example of RPC above where the client server communication will break if the server changes rotate() to rotate_image(). Every single client will have to be updated with this new function or they will crash when trying to talk to the server.
So REST is a way of thinking about client server communication, it is an architecture design/pattern. HTTP is a protocol that works under this way of thinking that focuses on simply transferring state of a resource between server and client.
Now it is important to understand that historically a lot of people, including web developers, didn't get this. So you got things like developers putting verbs into resource names to try and simulate Remote Procedure Call over HTTP. Things like
GET http://www.mywebsite.com/image/blur_image
And they would hard code the URI /image/blur_image into their client and then try and make sure the guys developing the server never changed the URI blur_image. You get back to all problems of RPC. As soon as the server guys move the resource blur_image (which is not really a resource to start with) to /image/blur_my_image the client falls over because it has that hard coded as an action to perform, rather than simply getting /image and doing what ever it wants to it.
So there are lot of examples on the web of doing REST wrong. Anything that tightly couples client and server communication is doing REST wrong. Your client should be able to survive URIs changing, or Content-Types being updated, without falling over. It can complain it doesn't understand a resource (eg Netscape Navigator 2.0 complaining it has no idea what a HTML5 document is), but it should complain that a URI has changed. This is the discoverability aspect of REST, which I haven't gone into too much, but basically your client should be able to start at the root of the server http://www.mywebsite.com and if it understand the content types it should be able to continue on to the resource it wants. You should never need to hard code a URI into your client other than the root of the server.
I could write a book about this stuff (and many have), but I hope that serves as a good introduction about what REST actually is.
#javafan I just checked the mykong example you provided. Please note that that is not standard http servlet implementation, it is a Jersy way of implimentinmg rest. So when you map all your URIs goes through this servlet com.sun.jersey.spi.container.servlet.ServletContainer and you write classes with annotation #path etc the Jersy runtime environment will do the necessary processing for you like converting the input and output objects to necessary formats (json, xml etc) depending on your configuration. You can write a simple servlet and add methods in it with #path annotation in it and that will be invoked inturn when you make the corresponding request. but the doGet and doPost methods are standard servlet methods that processes GET and POST method by default. You can ad another methods to the same servlet and add more qualifiers to process your request.
#GET, #Produces("xml") etc.
I hope this helps.
I am learning NodeJS and was able to make a server and an iPhone app that issues an HTTP GET request to the server and retrieve a JSON string from it. I didn't need to use socket.io for this. So why would I need to use it?
If you are just pulling JSON from the server your solution works fine. However suppose you want to push data from the server back to the client. Socket.io is a very elegant solution for doing this. Firstly because it handles the push side and secondly because it handles browser degradation gracefully as the 'jQuery of sockets'
In your wsdl, is it possible to connect directly to the wsdl(i.e - http://(url)?wsdl.
When I copy the wsdl locally to src/main/resources - I am able to connect generate objects including Web Service client, but when I try to connect to the WSDL that I copied from, I cannot generate. Perhaps I am not understanding QName and wsdllocation and even port for that matter.
I have searched fairly extensively on the web and there aren't that many clear cut examples. I know WebServiceTemplate makes things a LOT easier but without connecting to the WSDL, I cannot connect.
All I am trying to do is connect to the client. So it is a question more about Endpoints.
Also is it best practice to copy the WSDL locally. I am asking this because the client that we are working for has a 100 million environments.
Thanks.
Thanks
WSDL url will be like http://localhost:8080/<< Context-Name >>/<< ServiceName >>?wsdl
If you are generating the wsdl by running a server, then localhost:, should be given. If its a direct wsdl file, then try right clicking and opening it using a web browser. It will simply give you the link. You can use the same link to produce client stubs too.