JDBC 驱动

String username = "SYS@oracle";
String password = "";    
Connection conn = null;
try {
    PreparedStatement ps = conn.prepareStatement("select to_char(sysdate,'yyyy-MM-dd HH24:mi:ss') from dual;");
    ResultSet rs = ps.executeQuery();
    rs.next();
    System.out.println("sysdate is:" + rs.getString(1));
    rs.close();
} catch (Exception e) {
    e.printStackTrace();
} finally {
    if (null != conn) {
        conn.close();