//底层UserHandle
...
public UserHandle(){
      try{
        Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();
        String url = "jdbc:oracle:thin127.0.0.1:1521:Beyond";
        String user = "beyond";
        String psd = "beyond";
        tableName = "USER";
        cn = DriverManager.getConnection(url,user,psd);
        stmt = cn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE); //是不是这里要指明stmt的类别允许更新才行，我是这么做的，可以更新，另外通过stmt.executeQuery(sql)应该可以更新！！
      }
      catch(Exception ex){
        System.out.println(ex.toString());
      }
    }
    public void addUser(String sql)throws Exception{
      try{
        stmt.executeQuery(sql);
      }
      catch(SQLException ex){
        System.out.println("SQL statement is wrong!");
        System.out.println(ex.toString());
        throw ex;
      }
    }
    }

//上层类DoSQL
...
public void addUser(){
    UserHandle uh = new UserHandle();
    String sql = "Insert Into USER Values('";
    if(!checkIntegrality()){
      return;
    }
    sql += (userID +"','"+ userName +"','"+ realName +"','"+ sex +"','"
            + address +"','"+ telephone +"','"+ mobile +"','"+ email+"')");
    try{
      uh.addUser(sql); //调用UserHandle.addUser();
    }
    catch(Exception ex){
      errorInfo.addElement(ex.toString());
    }
  }

//我连的Oracle数据库，希望能给你点帮助，Good luck!