Is it possible to convert Delphi SoapServer application to use TCP/IP?
From your comment to your question it sounds like you are looking to get rid of SOAP, and use something else to communicatie over a TCP/IP connection.
The question one could ask is why do you want to convert to non-SOAP comm over TCP/IP?
But the answer to whether it is possible is: of course this is possible, there are many application servers using TCP/IP for communication without using SOAP as their communication's protocol.
You will need some kind of protocol for communication between server and clients. You could roll your own, but doing what SOAP is doing for you now: receiving and responding to commands from clients (or method invocation) and marshalling data/objects between server and clients is not a trivial task.
So I'd suggest you have a look at other remoting libraries for client/server communication, such as:
Remobjects: http://www.remobjects.com/
kbmMW: http://components4developers.com/
As others have said, SOAP is just XML on http/https, and usually does already use TCP.
That said, you could simply treat it as raw socket data or http data. i.e. you could make a client that just uses http POST to send a string to the server. The string would contain an XML SOAP request, and would be treated by the server as if it were SOAP. Likewise, you could build the server in a non-SOAP fashion, just accepting XML and returning XML, and the client wouldn't know the difference.
You can use Fiddler2 to play with this. You can build requests and send them via HTTP Post. The server has no idea that you're not a SOAP client.
Chris
If you're talking about pre-Delphi
2009 DataSnap, meaning COM based
DataSnap, then you have to use a third
layer utility to do the communication.
That utility named sockets.exe is
included with Delphi, and is in the
same dir as Delphi (Program
Files\\\\bin
If it is Delphi 2009 or better, then
DataSnap has built-in TCP/IP
functionality. You use
TDSTCPServerTransporter component.
Update: Ups! for some reason I did read DataSnap SoapServer (wich neither exists, but I did think of Soap Connection).
A Soap Server Application needs the "server" part, meaning a web server. SOAP is an technologie that runs over HTTP protocol, so I don't think it could be "converted".
DataSnap could do the job, or Indy TIdTCPServer or some of the derived classes.
Related
My application consists of a 'gateway' DataSnap REST server that is the first point of access for all clients. Depending on the username the clients pass in their requests (basic authentication), the request needs to be redirected to another DataSnap server. My question - is there anyway of building the 'gateway' server so that it simply redirects whatever the request is to another server based on the username, or other values in the HTTP request headers? I'm trying to avoid having to repeat all the server methods in the 'gateway' service i.e. I'd rather not 'chain' 2 requests together but somehow just have 1 request redirected.
Not sure if this is possible, but thought somebody might prove me wrong? I'm using Delphi XE2 and the DataSnap servers are Windows services.
I can see two options here:
use the first server only to return the address of the real server after logging in
or
use a Apache or NGINX reverse proxy in front of the Datasnap servers and RewriteRules based on the authentication data (however my Google-Fu for today seems to be exhausted, maybe this can be placed as a HTTP / Apache specfifc question here on SO)
Short version: the solution will depend on which level (HTTP, DataSnap, in between) you know where to target the request to.
If you can make the decision on the DataSnap level, there are two kinds of solutions:
The purists way to do this is write a generic DataSnap gateway that can interrogate a datasnap target server, dynamically creates both a proxy server and client for it, then intercepts the traffic and decides which datasnap target server to hand over the request to.
A more pragmatic approach would be the one you are afraid of.
Another approach would be on the HTTP level. That will only work if you can determine at the HTTP level to which target server a request should be handed over to.
I've got a custom HTTP Server created using Delphi 7 and Ararat Synapse which receives HTTP GET from another application with a simple set of variables.
For example: http://myserver.com/get?Variable1=adsds&Variable2=asdasdasdsa&Variable3=aasdsadasdsad
The application source is similar to this - http://searchco.de/codesearch/view/13374072
Now, my customer needs me provide a SOAP interface. Completely new to SOAP, I did some research and found it to be very complicated. I would like to know what's the easier way to incorporate this interface to my HTTP server. Or should I find ready made SOAP To HTTP Conversion app if there is such a software. Thank you.
Note: I'm not the original developer of the HTTP Server.
There is a Web Service Toolkit for Free Pascal and Delphi which can be used to write SOAP servers.
I have not yet used it myself but it is in active development and might be compatible with Synapse.
Update: the current version seems to include support for Internet Direct (Indy) and Synapse (HTTP server and TCP server).
You need to write a SOAP server, which not only generates SOAP responses from SOAP requests, but which also provides a WSDL document telling the users what requests they can make.
Since your completely new to SOAP here are some 'starter' links:
General:
SOAP, WDSL, HTTP, XSD? What the?
List of publicly available web services (I would start writring a small testapp that consumes SOAP)
With Delphi:
Developing Web Services with Delphi
Web Services Made Easy With Delphi
Web services with Delphi
The fact that you are using Delphi 7 makes things more difficult, since later versions have better support:
Debugging/Testing Win32 SOAP Web Services (D2007). Bob has more SOAP articles
For testing both serving and consuming SOAP you should use SoapUI, a great free tool (What is SOAPUI?).
Once you are up to the WDSL you should know what types of WSDL exist and the whole namespaces mess...
Long ago I started some "web applications" using Delphi 2007 and WebBroker (TWebModule). At the time I assumed you needed a webserver such as Apache or Microsoft IIS in order to create any sort of website. Additionally I don't use most of the Apache features (except for Virtual Server so I can have multiple domains on a single ip address and SSL). So to me Apache is just an extra layer and makes makes debugging difficult.
Now enter Indy (TIdHTTPServer). If I understand correctly, Indy IS a webserver. So by using Indy I am no longer bound to use Apache or some other webserver. Is this correct?
Will I have any issues supporting the Virtual Servers in an Indy environment? And what about SSL. I have searched the literature and from what I can see it fully supports SSL certificates.
I am now in the process of porting some of my application from WebBroker to Indy. This mostly entails replacing within my code references of Request: TWebRequest with ARequestInfo: TIdHTTPRequestInfo and references to Response: TWebResponse with AResponseInfo: TIdHTTPResponseInfo.
Is there anyway to use the TWebModule architecture within Indy so that I don't need to do all of this rewriting?
Lastly is there anything else I need to be concerned with? My goal is to take Apache out of the loop.
Yes, you can use Indy's TidHTTPServer as a webserver, but it's much lower-level than IIS or Apache. There is no concept of virtual servers - this you would have to implement yourself.
Indy does support SSL as well via the OpenSSL dll's.
I imagine the biggest concerns you will have will be security related...there are millions and millions of sites running Apache or IIS and there are a ton of people devoted to finding flaws in those platforms, with a bunch of people fixing some of those flaws as they come up. Not so with Indy... there's one or two guys that respond on newsgroups to bugs that you discover. (One guy in particular, who will probably respond to your question here as well.)
Now, I use Indy HTTP server (along with SecureBlackBox SSL support) and I find it to be great for my purposes.
Indy HTTP server calls the WinSock API, and is able to implement:
A full HTTP/1.1 server;
A full HTTPS server (using either OpenSSL libraries or other third parties, like SecureBlackBox).
AFAIK you can use Indy to publish web modules.
See http://www.2p.cz/files/2p.cz/downloads/howto/indy_soap_web_services_in_delphi.pdf
You can also use other servers, for instance directly the kernel-mode http.sys server, which is used by ISS and .Net WCF for instance, and known to be very stable and efficient (it bypasses the WinSock APIs). Of course, it will serve HTTPS conent, if needed. It is available in standard since Windows XP SP2, and therefore in Vista and Seven. Using this component will let Microsoft will do all the debugging work for you, and it will be updated with the host OS. I use it for instance in our Client-Server ORM, or directly to replace a deprecated DCOM connection, with very good speed and stability on customer side.
Regarding virtual servers - the HTTP 1.1 spec requires clients to send a Host request header so virtual servers know which domain is being used specifically to handle the case when multiple domains have the same IP. TIdHTTPRequestInfo has a Host property for that value. In fact, TIdHTTPServer internally validates to makes sure that an HTTP 1.1 request has the Host header before firing any of its OnCommand... events.
I am looking for a method to intercept http post requests with delphi without hooking any browser functions.Is that possible? How??
You could use something like WinPCap to grab intercept all packets looking specifically for packets on port 80 using the http protocol with a POST. There is a Delphi wrapper available which might be of some help. This is the same engine that is used by WireShark which would be useful by itself if your just having to do this manually or to debug an existing protocol.
In stead of doing this in Delphi, you might want to consider good and scripteable free solutions like Http Fiddler?
Edit:
If you want to write a proper and fully fledged proxy from scratch, that works well with most of the idiosyncrasies of possible http clients and servers, be prepared for at least a couple of man-months work.
If you are willing to use at least some base libaries, then look into this question.
--jeroen
You'd have to create an application that acted like a local Proxy Server that caught all requests made and then forwarded them out to the appropriate server.
I'm not sure which version of Delphi you're using, but you might want to check out this sample Proxy Server in C# and see if you can port the basics to suit your needs.
What are the advantages in using DataSnap compared to writing a
soapserver application.
I know Datasnap can use TCP/IP instead of soap.
Regards
Sandeep
With DataSnap you can export any number of datasets, and server methods, without the need of manually serialize them, adding built-in funcionality of parameterized querys, in wich value of the parameters are defined from the client. On the client side, you just have to connect to the remote datasource or methods to any data aware control using a ClientDataSet as data cache, with automatic update command generation.
SOAP is a more raw way to do everything, and IMHO the only thing you gain using WS is compatibility. If you are not using Delphi on the client side, then that is the way to go.
DataSnap is a remoting technology which directly supports Delphi database architecture. Actually DataSnap supports SOAP too - check the TSoapConnection component (but of course a plain SOAP server is not a Datasnap server also).
Be aware that currently exists two Datasnap implementation. The "older" one using DCOM/SOAP and a "newer", dbExpress-based one, supporting TCP and HTTP/REST.