This document discusses initializing a database when a Mule application starts up. It demonstrates using a Java class that implements the InitializingBean interface to clear existing database values. The class's afterPropertiesSet() method clears the old values. When the Mule application deploys, the database is initialized and cleared before the application fully starts. This allows database initialization to occur prior to any flows running that may interact with the database.

1. By Anirban Sen Chowdhary

2. Sometimes we require to initialize our database during the start of our application
in server.
We can also have the same requirement in our Mule application, where we require
to initialise the database while our application starts.
In my previous slide I have demonstrate initializing database with Groovy Script at
the start of application.
Here we will see doing the same with Spring beans and calling a Java class at the
startup

4. Yes .. We can .. I will show you this trick .. How ??

5. We can easily initialize the database by using a Java class that will
implement interface InitializingBean.
Let us consider we need to clear all the database value when our
Mule application will start in server.

6. Let us consider we have the following Mule flow, which will use the
database component to insert a new value into database table.
But we also require when this flow will start at server it will initialize the
database by clearing (deleting) the old values from the table

7. So, before we will start the flow in the server we will check the existing
values in database table which will be cleared when the application will be
deployed into server:-
As you can see the current database table has the above rows which we
need to clear when our Mule application will be deployed

8. The corresponding Mule flow will be as follows:-
Here is you can we are using Spring beans dbinitialization which is calling a Java class that is
responsible for the Database initialization

9. Now let’s see the Java class that will initialize the Database
So, here you can see the class is implementing InitializingBean interface which is
implementing afterPropertiesSet() method to clear the old values from Database

10. Now let’s start our application and we will see in the log at the beginning of the application is
deployed in server:-
And here you can see that the database is initialized and cleared before the application started
completely.

11. You can see now the table is empty and no data is there in database

12. And now if we hit http://localhost:8081/initial in our browser we will get the
following
The Mule flow has inserted a new row in the database table

13. And if we check the database now, we will find a new row is inserted there in the
Database table
So, this is a simple example of initializing Database with Spring beans
in Mule

14. In my next slide I will bring some other techniques in Mule
implementation .
Hope you have enjoyed this simpler version.
Keep sharing your knowledge and let our Mule community grow 