Web Services

WSDL Documents

An WSDL document describes a web service. It specifies the location of the service, and the methods of the service, using these major elements:

Element	Description
<types>	Defines the (XML Schema) data types used by the web service
<message>	Defines the data elements for each operation
<portType>	Describes the operations that can be performed and the messages involved.
<binding>	Defines the protocol and data format for each port type

SOAP

SOAP - Message Structure

A SOAP message is an ordinary XML document containing the following elements −

Envelope − Defines the start and the end of the message. It is a mandatory element.

Header − Contains any optional attributes of the message used in processing the message, either at an intermediary point or at the ultimate end-point. It is an optional element.

Body − Contains the XML data comprising the message being sent. It is a mandatory element.

Fault − An optional Fault element that provides information about errors that occur while processing the message.

ESB - Enterprice Integration Design Pattern

Editing Enterprise Integration Design Pattern(EIP) focuses on messaging patterns for enterprise application integration (EAI). Messaging makes it easier for programs to communicate across different programming environments (languages, compilers, and operating systems) because the only thing that each environment needs to understand is the common messaging format and protocol.

Messaging patterns define the means by which different elements in a message-passing system connect and communicate to enable interaction among objects within programs and among various types of software -- which may be written in different languages and exist on different platforms in multiple locations.[1]

First of all we should define EIPs and why we should use them. As the name implies, these are tested solutions for specific design problems encountered during many years in the development of IT systems. And what is all the more important is that they are technology-agnostic which means it does not matter what programming language or operating system you use. Patterns are divided into seven sections:

• Messaging Systems,
• Messaging Channels,
• Message Constructions,
• Message Routing,
• Message Transformation,
• Messaging endpoints,
• System management.