2. Model :
The first logical layer is the model layer. A Mule
model represents the run-time environment that
hosts services.
It defines the behavior of Mule when processing
requests handled by these services.
Consequently, the model that the Mule instance
would host would establish a runtime environment
optimized for asynchronous processing of
messages, as no synchronous reply is expected
anywhere in the overall message processing
chain.
3. Service :
A Mule service is composed of all the Mule entities involved in
processing particular requests in predefined manners.
A service is defined by a specific configuration. This
configuration determines the different elements, from the
different layers of responsibility, that will be mobilized to
process the requests that it'll be open to receive.
Depending on the type of input channel it uses, a service may
or may not be publicly accessible outside of the ESB.
For the time it gets handled by a service, a request is
associated with a session object.
As its name suggests, this object carries all the necessary
context for the pro-cessing of a message while it transits
through the service.
4. Transports :
The transport layer is in charge of receiving or
sending messages. This is why it's involved
with both inbound and outbound
communications.
A transport manifests itself in the configuration
by the following elements: connectors,
endpoints and transformers.
5. Connectors :
A connector is in charge of controlling the
usage of a particular protocol.
It's configured with parameters that are
specific to this protocol and holds any state
that can be shared with the underlying entities
in charge of the actual communications.
For example, the FileConnector can read and
write file system files.
6. Configuring connectors :
FileConnector
JDBC Connector
HTTP Connector
STDIO Connector
JMS Connector
Proceed to next slide to see the configuration
of all the above connectors.
7. FileConnector :
The configuration for file connector is as follows:
<file:connector name="FileConnector" streaming="false"
pollingFrequency="1000">
<file:expression-filename-parser/>
</file:connector>
8. JDBC Connector :
The configuration for JDBC connector is as
follows :
<jdbc:connector name="jdbcConnector"
dataSource-ref="dataSource“>
<jdbc:query key="statsInsert" value="insert into
alerts values (0, 344, Sindhu', Vankam')"/>
</jdbc:connector>
9. HTTP Connector :
The configuration for HTTP connector is as
follows :
<http:connector name="HttpConnector"
proxyHostname="${proxyHostname}"
proxyPort=="${proxyPort}"
proxyUsername="${proxyUsername}"
proxyPassword="${proxyPassword}"/>
10. STDIO Connector :
The configuration for STDIO connector is as
follows :
<stdio:connector
name="SystemStreamConnector"
promptMessage="Please enter something:"
messageDelayTime="1000" />
11. JMS Connector :
The configuration for JMS connector is as
follows :
<jms:activemq-connector
name="jmsQueueConnector"
specification="1.0.2b"
brokerURL="tcp://localhost:61616" />
12. Endpoints :
Inbound and outbound endpoints exist in the context of a
particular service and represent the expected entry and exit
points for messages, respectively.
These end-points are defined in the inbound and outbound
routers.
It's also possible to define an inbound endpoint in a response
router.
In that case, the inbound endpoint acts as a response
endpoint where asynchronous replies will be consolidated
before the service returns its own response.
Global endpoints can be considered abstract entities that get
reified only when referenced in the context of a service: as
such, they're a convenient way to share common
configuration attributes.
13. Transformer :
A transformer optionally changes incoming or outgoing messages in
some way.This is usually done to make the message format
useable by a downstream function
For examples, the ByteArrayToString transformer converts byte
arrays into String objects.If we want our own transformers to
convert input we can write our own java and we can call from the
mule.
We can implement custom java transformer by extends
AbstractTransformer and AbstractMessageAwareTransformer.
AbstractTransformer is a normal Transformer, it will carry only
payload in the sense input/result from before execution.
AbstractMessageAwareTransformer is a special transformer, It
will carry payload, messahe properties of mule and alo details
regarding exception.
14. Routers :
Routers play a crucial role in controlling the trajectory a message will follow
when it transits in Mule.
They're the gatekeepers of the endpoints of a service. In fact, they act like
railroad switches, taking care of keeping messages on the right succession
of tracks so they can reach their intended destinations.
A router is the object that does something with messages once they have
been received by a connector, or prior to being sent out by the connector.
pass-through-router: Input will pass as it is to outbound from inbound.
Single service will be available.
filtering-router: input will pass based on condition it's like filtering input.
Multiple Services will be available.
chaining-router: Every statement will pick up by procedure functionality,
nothing but there is no condition after finishing one service it will go to the
next service. Multiple Services will be available.
etc...
15. Filter :
A filter optionally filters incoming or outgoing
messages that are coming into or going out from a
connector.
For example, the File Provider comes with a
FilenameWildcardFilter that restricts which files
are read by the connector based on file name
patterns.
For example only files with the .xml extension can
be routed.
Note: writing condition is filtering-router and way
of condition is filter. Based on filter, service will be
picking up by filtering-router.
16. Components :
Components are usually business objects.
They are components that execute business
logic on an incoming event.
Components are standard JavaBeans
(containers).
There is no Mule-specific code in components,
it is a java class to implement business logic
especially.
