Mule ESB transformers transforms the message to required format which helps the developer to integrate the system easily with other applications.

1. 4/4/2016 Manirathnam Gudi

2. 4/4/2016 Manirathnam Gudi
Transformers are used to transform message or event payloads to and from
different types
Transformers are used to convert inbound data to an object type required by the
UMO Component or outbound to an object type required by the transport such as a
JMS Message.
Multiple transformers can be chained together to get a finer grained transformer
implementation that are easier to reuse.

3. 4/4/2016 Manirathnam Gudi
How to alter the message using Transformers
Transformer can alter a message in different ways:
 Payload type transformation- The data type of the message payload is transformed from one form to
another.
Example: java.util.Map is transformed into a javax.jms.MapMessage.
 Payload format transformation- The data format of the message payload is transformed from one form to
another.
Example: DocBook XML instance is transformed into an XSL-FO instance.
 Properties transformation- The properties of the message are modified, whether by adding new
properties or by removing, renaming, or changing the values of existing properties.
Example: Message needs a particular property to be set before being sent to a JMS destination

4. 4/4/2016 Manirathnam Gudi
Transformer Workflow

5. 4/4/2016 Manirathnam Gudi
Transformers can be configured in two ways.
 Configure it locally - We can configure a local transformer at any point in the program or on the
endpoint or in a Flow .
 Configure it Globally – We can also configure a global transformer before any <model> or <flow>
elements in your Mule configuration file and later reference it.
How to configure Transformer

6. 4/4/2016 Manirathnam Gudi
Types of Transformers
Transformers can be categorized into two types :
 Built-in Transformers
 Custom Transformers
 Default Transformers : There are many Standard pre existing Transformers provided in Mule
3.7 which can be used easily to convert the data.
For example :
 Object to JSON Transformer
 Object to String Transformer
 JMS Message to Object Transformer
 Object to JMS Message
 Object to XML
 XML to Object

7. 4/4/2016 Manirathnam Gudi
 Custom Transformers :
 If you are not satisfied with the default/built in transformers which are already provided by Anypoint
Studion (or) If there is any no transformer which meets your requirement then you can develop a
transformer on your own by customizing the code by writing the java code by implementing a Custom
transformer class org.mule.api.transformer.Transformer .
 Depending on your needs we can extend AbstractTransformer or AbstractMessageAwareTransformer .
 We build Custom transformers if it's impossible to realize with an existing transformer or a chain of
transformers.

8. 4/4/2016 Manirathnam Gudi
 References :
 https://docs.mulesoft.com/mule-user-guide/v/3.7/using-transformers
Thank you