Mule flows are sequences of message processing events that can validate, enrich, transform, process with custom logic, log, and evaluate messages. The building blocks of a Mule flow include optional message sources that receive messages, message processors that process messages in various ways, message processing blocks that combine processors, and endpoints that insert or extract data and implement transport channels.

1. MULE FLOWS

2. At the simplest level, Flows are sequences of message-
processing events. As the following schematic illustrates, a
message that enters a flow may be:
validated (filtered)
enriched (appended)
transformed into a new format
processed by custom-coded business logic
logged to a database
evaluated to determine what sort of response gets
returned to party that submitted the original message

3. Sample Mule Flow :

4. Flow Building Blocks :
The following sub-sections detail the various types of
building blocks (and processing blocks) that can populate a
Mule Flow.
a. Message Source (Optional)
b. Message Processors
c. Message Processing Blocks
d. End Points

5. Message Source (Optional)
The first building block in most Flows is a Message
Source, which receives messages from one or more external
sources, thus triggering a Flow instance. Each time it receives
another message, the Message Source triggers another Flow
instance.

6. Message Processors
Typically, these are pre-packaged units of functionality
that process messages in various ways. Except for Message
Sources, all the building blocks in a Flow qualify as Message
Processors. Unlike the Mule Services they have largely
supplanted, Message Processors offer the following
advantages:
They don’t have to be connected to each other with
routers, endpoints, and VM queues in the rigid fashion
required for Services
Multiple Message Processors can be combined into
various structures that provide the exact functionality you
need for your application

7. Message Processing Blocks
Mule provides several ways to combine multiple
message processors into functional processing blocks.
For instance, the Composite Source scope allows you
to embed into a single message source two or more inbound
endpoints, each one listening to a different transport channel.
Whenever one of these listeners receives an incoming
message, it triggers a flow instance and starts the message
through the message processing sequence.

8. Endpoints
As previously mentioned, Endpoints implement
transport channels that facilitate the insertion or extraction of
data from Flows. Endpoints serve a diverse variety of roles,
depending on how they are configured. For example, they
can, as previously mentioned, serve as Inbound or
Outbound conduits. They can implement one-way or
request-response exchange patterns. And, in certain
situations, you can embed other types of message
processors, such as transformers or filters, into endpoints.

9. THANK YOU