程序代码：

    private static String url = \"jdbc:oracle:thin:@localhost:1521:system\";

    private static String user = \"system\";
    private static String pw = \"19821227\";
    private static Connection con = null;
    public static Connection getConnection() {
        if(con==null){
            try {
                Class.forName(\"oracle.jdbc.driver.OracleDriver\");
                con = DriverManager.getConnection(url, user, pw);
            } catch (ClassNotFoundException e) {
                e.printStackTrace();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        return con;
    }