Connection conn = DriverManager.getConnection(url, "erya", "test");
System.out.println("success connect");
System.out.println((( org.postgresql.jdbc3g.Jdbc3gConnection)conn).getURL());
System.out.println((( org.postgresql.jdbc3g.Jdbc3gConnection)conn).getUserName());
System.out.println((( org.postgresql.jdbc3g.Jdbc3gConnection)conn).getServerMajorVersion()); //大版本号 9
System.out.println((( org.postgresql.jdbc3g.Jdbc3gConnection)conn).getServerMinorVersion()); //小版本号 3 2
System.out.println((( org.postgresql.jdbc3g.Jdbc3gConnection)conn).getDBVersionNumber()); //版本号 9.3beta1 9.2.3
