For Ms-Access[Type-1]
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection con = DriverManager.getConnection("jdbc:odbc:oradsn","system","a");
Statement st = con.createStatement();
For Oracle[Type-2]
Connection con = DriverManager.getConnection("jdbc:oracle:oci8:@xe","system","a");
Statement st = con.createStatement();
[Type 4]
Class.forName("oracle.jdbc.OracleDriver");
Connection con = DriverManager.getConnection("jdbc:oracle:oci8:@orcl", "system", "a");
Statement st = con.createStatement();