Hyd MuleSoft-Meetup-May 29,2021 | Migrating Mule 3 Java-related code to Mule 4

1. 29th March 2021 , 4pm IST
Hyderabad MuleSoft Meetup
MIGRATING MULE 3 JAVA RELATED CODE TO MULE 4

2. Agenda
•Community Details!
•Introduction Of Organizers and Speakers
•Important Announcements – Anypoint Studio New Release
•Migrating Mule 3 Java Related Code to Mule 4 by Piyush Sharma
•Queries
•Trivia Quiz
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3. Community Details
• Register for Meetups : https://meetups.mulesoft.com
•Register for Official Training platform : https://training.mulesoft.com
•MuleSoft forum : https://help.mulesoft.com
•For all blogs : https://blogs.mulesoft.com/
•Anypoint platform : https://anypoint.mulesoft.com
•Join Exam Readiness Sessions ! (Remind me to share at the end of the session)
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4. Hyderabad Meetup Leaders
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5. Speaker of the day!
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• Working as an Integration developer with 5+ years’
of experience in different domains like retail,
banking, consumer goods, healthcare etc and
helping organizations in their digital transformation
journey.
• Started career with TIBCO and slowly moved to
MuleSoft.
• Happy to help and contribute to MuleSoft
community and eventually learning new things in
process. Love to travel and watch movies in free
time.
Reachable:
https://www.linkedin.com/in/piyush3192/

6. Anypoint Studio Latest Release

7. 2
New Anypoint Studio 7.9.0
• Anypoint Studio 7.9 enables users to use a dark theme, and upgrades its
underlying infrastructure to Eclipse 4.18 and Java 11, adding official
support for macOS Big Sur.
• This version also introduces improvements for Dataweave code
experience and enhanced macOS experience by notarizing Studio as a
macOS application.

8. 2
New Anypoint Studio 7.9.0

9. By Piyush Sharma,
Sr.Integration Developer at Billennium
Mule 3 Java code Migration to Mule 4

10. 10
Some Comparisons from Mule 3 to Mule 4

11. 11
Some Comparisons from Mule 3 to Mule 4

12. 12
Mule 3 Java Working

13. 13
Mule 3 Java Working

14. 14
Mule 4 Java Working
Several ways of calling Java:
• Calling Static Java Methods from DataWeave
• Scripting Module (Ruby, Python,Groovy,JS)
• Java Module

15. 15
A look on Mule 3 Java Code
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Mule API Packages
Callable Interface
Getting payload and flow
variables
Setting flow variables and
return payload

16. 16
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Basic knowledge of Mule 3 Java class
Mule API Package Imports:
import org.mule.api.lifecycle.Callable;
import org.mule.api.MuleEventContext;
import org.mule.api.transport.PropertyScope;
Class with callable interface:
public class AddtwoNum implements Callable
Oncall method
@Override
public Object onCall(MuleEventContext eventContext) throws Exception

17. 17
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Basic knowledge of Mule 3 Java class
Read flow Variables according to their scope:
myVar = eventContext.getMessage().getProperty(“name", PropertyScope.INVOCATION);
Set flow Variables according to their scope:
eventContext.getMessage().setProperty(“name", “Max”, PropertyScope.INVOCATION);
Read payload:
String payload = (String) eventContext.getMessage().getPayload();
Return payload:
return eventContext.getMessage().getPayload();

18. 18
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Migrating Java functionality Mule 3 to Mule 4
Combined Approach:
• Java classes cannot be simply migrated, requires manual efforts.
• Utilize MMA tool along with custom changes.
• Migrate most of the code and connector configuration using MMA.
Identify and Address:
• Identify Java classes which you really need to migrate.
• Utilize Dataweave 2.0 at most of the places and scrap the old used java class for data
transformation for improved performance and readability.
• List down the java classes which have to be migrated.

19. 19
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Migrating Java functionality Mule 3 to Mule 4
Work with classes:
• Once class finalized, start importing them. Please watch out for classes which import other classes
as well.
• Fix project structure and error, you might require to add dependency which are used in java class.
• Sometimes you need to allow certain packages in studio which gets restricted.
• After importing classes, there will be errors in classes as well, that’s where the manual efforts needs
to be done.

20. 20
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Migrating Java functionality Mule 3 to Mule 4
Modify classes:
• Remove all imports related to org.mule.api.*, as they are no longer supported in Mule 4.
• Remove callable interface notation from class declaration(public class AddTwoNum implements Callable ->
public class AddTwoNum )
• Modify onCall method , rename it and make it static.
• Check for flow variables or properties which code reads, you now need to pass them as a parameters in
static method.
• Check for return type of method, if it doesn’t return anything it will be void, otherwise based on return
datatype.

21. Demo

22. Queries?

23. Maintenance Exams?

24. Trivia Quiz !

25. Enter Your Full Valid Name (no nick Names are allowed)
Only those who have registered and joined the session will be
allowed!
Goto Mobile Browser
Enter :
kahoot.it

26. Read the options and Tap the colour which
has correct answer.

27. Thank you