Both main( ) and serverMain( ) call the connecter( ) method, which returns a JDBC Connection object. The Connection object is the basis for all subsequent SQL operations.
Both main( ) and serverMain( ) call connecter( ) with a parameter that specifies the JDBC driver for the server- or client-side environment. The returned Connection object is then passed as an argument to the other methods of the JDBCExamples class. By isolating the connection actions in the connecter( ) method, JDBCExamples’ other methods are independent of their server- or client-side environment.