From this LINK
The JDBC driver is typically located at the location WL_HOME/server/lib of the installation directory. The file is ojdbc7.jar or ojdbc6.jar (for new versions of WLS), or ojdbc14.jar (for older versions of WLS).
One way to check the JDBC driver version is to open the ojdbc jar file and go inside the META-INF folder, and then open the "MANIFEST.MF" file. The version can be seen next to "Specification-Version".
Another way is to run the command below on the location mentioned previously:
java -jar ojdbc6.jar -getversion
Note that you must use the JDBC JAR file intended for the version of the JDK that you are running. For example, "ojdbc5.jar" is intended for use with JDK 1.5. So if you run JDK 1.5 with the JDBC driver JAR file "ojdbc6.jar" then a "java.lang.UnsupportedClassVersionError: Bad version number in .class file" error message will be thrown when performing this check.
