Voxxed days amsterdam 2025

Looking forward to it!

References

VoxxedDays Amsterdam

https://amsterdam.voxxeddays.com/

Using different JDBC drivers

So I had the problem that I needed to connect to both Oracle databases as well as Postgres database.

And just including the dependencies in my Maven was not enough.

One of the drivers gets overwritten by another driver in the service provider mechanism.

At first I tried to register them by hand (which works):

DriverManager.registerDriver(new org.postgresql.Driver());
DriverManager.registerDriver(new OracleDriver()); return DriverManager.getConnection(url, user, password);

Or, you could do the extreme magic thing^{1 2}:

Class.forName("org.postgresql.Driver");
Class.forName("oracle.jdbc.driver.OracleDriver"); return DriverManager.getConnection(url, user, password);

Which causes both drivers to run a static block registering themselves on the DriverManager in the same fashion as my code on top.

All this, because the service provider mechanism that automatically loads the JDBC driver, only allows one Driver to be registered³.

References

[1] StackOverflow - What is the difference between "Class.forName()" and "Class.forName().newInstance()"?

https://stackoverflow.com/questions/2092659/what-is-the-difference-between-class-forname-and-class-forname-newinstanc/2093236#2093236

[2] Baeldung - Loading JDBC Drivers

https://www.baeldung.com/java-jdbc-loading-drivers

[3] Baeldung - Java Service Provider Interface

https://www.baeldung.com/java-spi