What is Oracle Mediator Component?

Mediator is the load balancer which can route, filter, validate and transform data from the service providers to external references

• Route: determines the service component to which the message has to be sent
• Validate: validate the incoming payload information
• Filter: Filters the payload for specific information before routing it to the specific component
• Transformation: Transforms data from one xsd format to another using XSL Mapper

the code specific to mediator in the composite.xml will be like

<component name="ConversionMediator">
<implementation.mediator src="ConversionMediator.mplan"/>
</component>

Mediator component in the design view consist of

Name: Name of the mediator component

WSDL Url: the service provider URL

Port Type: The port on which the request message is sent

Resequence Level: Whether the sequencing of the incoming message will be taken care commonly[Operation] or for each component [component]

Priority: priority set for parallel routing rule

validate XSD: validate the schema for the incoming message

Callouts: specifies java classes for extra logic in programmatic way

Resequence:

Standard -> the incoming message will be sequence based on the sequence id

Best Effort -> sequencing based on the best possible way

FIFO ->  sequencing of message based on the time of the arrival of the message

Static Routing:

routing rule based on static information

Filter -> content based or header based routing

Transform -> using xsl mapper file

validate -> using schematron file

Assign -> assign header,payload values of the message from source to target

sequential -> rule executed one after the other

Parallel -> rule executed in parallel. Priorities are given to the parallel rule

Dynamic Routing:

routing rule based on external rule which keeps changing based on the invocation context

Fault Handling: This is handled in composite or at the component[mediator] level by specifying fault policies

Event Handling: A mediator can subscribe or publish an event