Main class manifest information for ojdbc6.jar

Question

I checked the META-INF/MANIFEST.MF file under ojdbc6.jar and the following is the result.

Manifest-Version: 1.0
Implementation-Vendor: Oracle Corporation
Implementation-Title: ojdbc6.jar
Implementation-Version: Oracle JDBC Driver version - "11.1.0.7.0-Produ
 ction"
Implementation-Time: Wed Sep 10 15:03:50 2008
Specification-Vendor: Oracle Corporation
Sealed: true
Created-By: 1.6.0 (Sun Microsystems Inc.)
Specification-Title: Oracle JDBC driver classes for use with JDK6
Specification-Version: Oracle JDBC Driver version - "11.1.0.7.0-Produc
 tion"
Main-Class: oracle.jdbc.OracleDriver

Name: oracle/sql/converter_xcharset/
Sealed: false

Name: oracle/sql/
Sealed: false

Name: oracle/sql/converter/
Sealed: false

Out of these manifest information, the line Main-Class: oracle.jdbc.OracleDriver caught my attention. I understand the concept of Main-Class attribute. But I'm not sure why this class has to be main class.

Answer 1

Apparently, This seems to be a provision given to us by oracle to check the version of Oracle driver for any give ojdbc6.jar file.

https://docs.oracle.com/cd/B28359_01/java.111/b31224/getsta.htm#i1008663

To check the driver version, All you just have to do is to run java -jar ojdbc6.jar .

C:\Users\raja\Downloads>java -jar ojdbc6.jar
Oracle 12.1.0.1.0 JDBC 4.0 compiled with JDK6 on Thu_Apr_04_15:06:58_PDT_2013
#Default Connection Properties Resource
#Thu Nov 05 15:51:12 GMT 2015