The document discusses the Simple Object Access Protocol (SOAP), detailing its role as a messaging format for XML web services and its evolution into a core component of service-oriented architecture. It explains the structure of SOAP messages, including the mandatory envelope, body, and optional header sections, as well as the roles of SOAP nodes in transmitting and processing messages. Additionally, it highlights common uses of SOAP header blocks and the handling of exceptions within the body construct.

1. Service Oriented Architecture: 10
SOA Technology: SOAP
Prof Neeraj Bhargava
Vaibhav Khanna
Department of Computer Science
School of Engineering and Systems Sciences
Maharshi Dayanand Saraswati University Ajmer

2. Simple Object Access Protocol (SOAP)
• SOAP was originally conceived as a technology
to bridge the gap between disparate RPC-
based communication platforms
• SOAP has evolved into the most widely
supported messaging format and protocol for
use with XML Web services
• SOAP is also frequently referred to as the
Service-Oriented Architecture (or Application)
Protocol

3. SOAP Message formats
• The SOAP specification establishes a standard
message format that consists of an XML
document capable of hosting RPC and document-
centric data
• This facilitates synchronous (request and
response) as well as asynchronous (process
driven) data exchange models
• Thus SOAP establishes two primary standard
message formats.
• Additionally the SOAP message may deliver its
data as an attachment.

5. SOAP messaging framework
• SOAP institutes a method of communication
based on Web services framework
• A SOAP node represents the processing logic
responsible for transmitting, receiving, and
performing a variety of processing tasks on SOAP
messages.
• These are also sometimes presented as SOAP
server or a SOAP listener or SOAP routers
• SOAP node as the underlying transport
mechanism for a Web service.

6. SOAP Node Types
• Like Web services, SOAP nodes can exist as
initial senders, intermediaries, and ultimate
• receivers. Whereas Web services are also
classified as requestors and providers,
• SOAP nodes performing the equivalent tasks
(sending, receiving) are referred to as
• SOAP senders and SOAP receivers

7. SOAP Node Types
• Fundamental SOAP node types along a
message path

8. Roles of SOAP Nodes
• As with Web service roles, the same SOAP node
can act as different types depending on its
position within the message path and the state of
the current business activity.
• For instance, a SOAP node transmitting a
message as the initial sender can later receive a
response as the ultimate receiver.
• A intermediary SOAP node go through the
transition of being a SOAP receiver and then
becoming a sender during the processing of a
SOAP message.

9. SOAP message structure
• The container of SOAP message information is referred to as a
SOAP envelope.
• The root Envelope element that frames the message
document consists of a mandatory body section and an
optional header area
<env:Envelope xmlns:env="http://www.w3.org/2020/05/soap-
envelope">
<env:Header>
...
</env:Header>
<env:Body>
...
</env:Body>
</env:Envelope>

10. The Header construct
• The SOAP header is expressed using the Header construct, which
can contain one or more sections or blocks.
<env:Envelope
xmlns:env="http://www.w3.org/2020/05/soap-
envelope">
<env:Header>
<n:shipping >
UPS
</n:shipping>
</env:Header>
<env:Body>
...
</env:Body>
</env:Envelope>

11. Common uses of header blocks
Common uses of header blocks include:
• Implementation of (predefined or application-
specific) SOAP extensions, such as those
introduced by second-generation specifications
• Identification of target SOAP intermediaries
providing supplementary meta information about
the SOAP message
• While a SOAP message progresses along a
message path, intermediaries may add, remove,
or process information in SOAP header blocks.

12. Body construct
• Body construct, this section acts as a
container for the data being delivered by the
SOAP message.
• Data within the SOAP body is often referred to
as the payload or payload data.
• The Body construct can also be used to host
exception information within nested Fault
elements

13. Example Body construct

14. Fault construct
• The Fault construct consists of a series of system
elements used to identify characteristics of the
exception.

15. SUMMARY SOAP
• Implementations of the SOAP messaging framework
can be collectively conceptualized as an end-to-end
messaging engine that drives communication
throughout contemporary service-oriented
architectures.
• A SOAP message consists of a simple XML document
structure.
• The parent envelope construct houses an optional
header and a required body construct.
• Exception information can be placed in a special Fault
element that is nested within the message body.

16. Assignment
• Discuss the structure and functioning of
simple SOAP Messages