In Type 4 driver, a pure Java-based driver that communicates directly with vendor's database through socket connection.
This is the highest performance driver available for the database and is usually provided by the vendor itself.
This kind of driver is extremely flexible, you don't need to install special software on the client or server.
Further, these drivers can be downloaded dynamically.
MySQL's Connector/J driver is a Type 4 driver. Because of the proprietary nature of their network protocols,
database vendors usually supply type 4 drivers.
Serves as a pure java driver and auto downloadable.
Does not require native libraries to be installed on the client machine.
Uses the database server specific protocol and thereby it is secure to use this driver.
Does not require a middleware server.
It uses database specific proprietary protocol and is DBMS vendor dependent.
Thin Driver for Oracle Corporation.:
If you are accessing one type of database, such as Oracle, Sybase, or IBM, the preferred driver type is 4.
If your Java application is accessing multiple types of databases at the same time, type 3 is the preferred driver.
Type 2 drivers are useful in situations where a type 3 or type 4 driver is not available yet for your database.
The type 1 driver is not considered a deployment-level driver and is typically used for development and testing purposes only.