Java Programming Language

Types of Drivers
There are many possible implementations of JDBC drivers. These
implementations
are categorized as follows:
n Type 1 - drivers that implement the JDBC API as a mapping to another data
access API, such as ODBC. Drivers of this type are generally dependent on a
native library, which limits their portability. The JDBC-ODBC Bridge driver
is an
example of a Type 1 driver.
n Type 2 - drivers that are written partly in the Java programming language
and
partly in native code. These drivers use a native client library specific to
the data
source to which they connect. Again, because of the native code, their
portability
is limited.
n Type 3 - drivers that use a pure Java client and communicate with a
middleware
server using a database-independent protocol. The middleware server then
communicates the client's requests to the data source.
n Type 4 - drivers that are pure Java and implement the network protocol for
a
specific data source. The client connects directly to the data source.