Herong's Tutorial Notes on Perl - Part B
Dr. Herong Yang, Version 4.11

SOAP::Transport::HTTP Modules

This chapter describes:

  • Introduction to SOAP::Transport::HTTP::Daemon module, and sample programs.

SOAP::Transport::HTTP::Daemon Module

The SOAP::Transport::HTTP::Daemon module is very similar to the SOAP::Transport::TCP::Server module. It offers two functionalities: 1. Taking SOAP requests as a SOAP server; 2. Interacting with application modules to handle the requests as a SOAP server side API.

The SOAP::Transport::HTTP::Daemon module supports the same methods as the SOAP::Transport::TCP::Server module. See the previous chapter for details of those mothods.

Here is a sample program to show you how to create a SOAP server with HTTP as the transportation protocol and dispatch SOAP requests to application modules:

#- SoapHttpServerTrace.pl
#- Copyright (c) 2002 by Dr. Herong Yang
   use SOAP::Lite +trace;
   use SOAP::Transport::HTTP;
   my $daemon = SOAP::Transport::HTTP::Daemon
      -> new (LocalAddr => 'localhost', LocalPort => 8001, listen => 5);
   $daemon -> dispatch_to('Hello::hello');
   print "Contact SOAP server at ", $daemon->url, "\n";
   $daemon->handle();

To test the server, you need a SOAP client program that can talk to the server using HTTP protocol. Here is a sample code:

#- SoapHttpClientTrace.pl
#- Copyright (c) 2002 by Dr. Herong Yang
   use SOAP::Lite +trace;
   my $client = SOAP::Lite->new();
   $client->uri('urn:Hello');
   $client->proxy('http://localhost:8001');
   my $som = $client->hello("Herong");
   my $output = $som->result;
   print $output . "\n";

Notice that this client program is the same as the client program that talks to the server using TCP protocol, except the prefix code in the server URL. See the "proxy('http://localhost:8001')" function call.

Now run the server program first, then run the client program in a different command window. You should get the following output in the client program window:

SOAP::Transport::new: ()
SOAP::Serializer::new: ()
SOAP::Deserializer::new: ()
SOAP::Parser::new: ()
SOAP::Lite::new: ()
SOAP::Transport::HTTP::Client::new: ()
SOAP::Lite::call: ()
SOAP::Serializer::envelope: ()
SOAP::Serializer::envelope: hello Herong
SOAP::Data::new: ()
SOAP::Data::new: ()
SOAP::Data::new: ()
SOAP::Data::new: ()
SOAP::Data::new: ()
SOAP::Transport::HTTP::Client::send_receive: HTTP::Request=HASH(0x25c5
a60)
SOAP::Transport::HTTP::Client::send_receive: POST http://localhost:800
1/
Accept: text/xml
Accept: multipart/*
Content-Length: 500
Content-Type: text/xml; charset=utf-8
SOAPAction: "urn:Hello#hello"

<?xml version="1.0" encoding="UTF-8"?><SOAP-ENV:Envelope xmlns:SOAP-EN
C="http://schemas.xmlsoap.org/soap/encoding/" SOAP-ENV:encodingStyle="
http://schemas.xmlsoap.org/soap/encoding/" xmlns:SOAP-ENV="http://sche
mas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/1999/XMLS
chema-instance" xmlns:xsd="http://www.w3.org/1999/XMLSchema"><SOAP-ENV
:Body><namesp1:hello xmlns:namesp1="urn:Hello"><c-gensym3 xsi:type="xs
d:string">Herong</c-gensym3></namesp1:hello></SOAP-ENV:Body></SOAP-ENV
:Envelope>
SOAP::Transport::HTTP::Client::send_receive: HTTP::Response=HASH(0x24b
017c)
SOAP::Transport::HTTP::Client::send_receive: HTTP/1.1 200 OK
Date: Sat, 28 Dec 2002 17:15:01 GMT
Server: libwww-perl-daemon/1.24
Content-Length: 522
Content-Type: text/xml; charset=utf-8
Client-Date: Sat, 13 Mar 2004 17:15:01 GMT
Client-Peer: 127.0.0.1:8001
SOAPServer: SOAP::Lite/Perl/0.51

<?xml version="1.0" encoding="UTF-8"?><SOAP-ENV:Envelope xmlns:SOAP-EN
C="http://schemas.xmlsoap.org/soap/encoding/" SOAP-ENV:encodingStyle="
http://schemas.xmlsoap.org/soap/encoding/" xmlns:SOAP-ENV="http://sche
mas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/1999/XMLS
chema-instance" xmlns:xsd="http://www.w3.org/1999/XMLSchema"><SOAP-ENV
:Body><namesp1:helloResponse xmlns:namesp1="urn:Hello"><s-gensym3 xsi:
type="xsd:string">Hello Herong</s-gensym3></namesp1:helloResonse></SOA
P-ENV:Body></SOAP-ENV:Envelope>
SOAP::Deserializer::deserialize: ()
SOAP::Parser::decode: ()
SOAP::SOM::new: ()
Hello Herong
SOAP::Lite::DESTROY: ()
SOAP::Serializer::DESTROY: ()
SOAP::Data::DESTROY: ()
SOAP::Data::DESTROY: ()
SOAP::Data::DESTROY: ()
SOAP::Data::DESTROY: ()
SOAP::Data::DESTROY: ()
SOAP::Transport::DESTROY: ()
SOAP::Transport::HTTP::Client::DESTROY: ()
SOAP::SOM::DESTROY: ()
SOAP::Deserializer::DESTROY: ()
SOAP::Parser::DESTROY: ()

You should get the following in the server program window:

SOAP::Serializer::new: ()
SOAP::Deserializer::new: ()
SOAP::Parser::new: ()
SOAP::Server::new: ()
SOAP::Transport::HTTP::Server::new: ()
SOAP::Transport::HTTP::Daemon::new: ()
Contact SOAP server at http://localhost:8001/
SOAP::Server::handle: ()
SOAP::Deserializer::deserialize: ()
SOAP::Parser::decode: ()
SOAP::SOM::new: ()
SOAP::Data::new: ()
SOAP::Data::DESTROY: ()
(eval): Herong
SOAP::Server::handle: Hello Herong
SOAP::Serializer::envelope: ()
SOAP::Serializer::envelope: helloResponse Hello Herong
SOAP::Data::new: ()
SOAP::Data::new: ()
SOAP::Data::new: ()
SOAP::Data::new: ()
SOAP::Data::new: ()
SOAP::SOM::DESTROY: ()

A couple of the interesting things to note here:

  • The SOAP XML request is delivered as a true HTTP request using the POST method.
  • The HTTP request as an extra header line: SOAPAction: "urn:Hello#hello".
  • The SOAP XML response is delivered as a true HTTP response with a couple of extra header lines.
Dr. Herong Yang, updated in 2006
Herong's Tutorial Notes on Perl - Part B - SOAP::Transport::HTTP Modules