How to register a JDBC driver?

There are several ways:

• Explicit use of Class.forName():

  // Loads the driver class, which registers itself automatically upon initialization.
  Class.forName("com.mysql.cj.jdbc.Driver");
  

  This method was common in older versions of Java but is now considered deprecated.

• Using DriverManager.registerDriver():

  import java.sql.DriverManager;
  import java.sql.Driver;
  
  // Creates an instance of the driver and explicitly registers it.
  DriverManager.registerDriver(new com.mysql.cj.jdbc.Driver());
  

  This method is also not preferred in most cases.

• Automatic loading via Service Provider Mechanism: The modern and recommended way. JDBC drivers are provided as JAR files containing information about themselves in the META-INF/services directory in a file named java.sql.Driver. The JVM automatically finds and loads these drivers when DriverManager is first accessed. You just need to add the driver JAR file to the classpath.

Comparison of approaches:

Method	Recommended	Description
Class.forName()	No	Deprecated, requires explicit class name of the driver.
DriverManager.registerDriver()	No	Requires creating an instance of the driver and registering it explicitly.
Service Provider Mechanism	Yes	Automatic driver loading from classpath upon first access to DriverManager.

The most preferred way in modern applications is to rely on the automatic driver loading mechanism via Service Provider Mechanism by simply adding the required driver JAR file to the project dependencies.