and when i use integer.parseint instead of typecasting into integer then i get a error
symbol : method parseInt(java.lang.Object)
location: class java.lang.Integer int accountno=(Integer.parseInt(mAccthld.getValueAt(tAcctHld.getSelectedRow(),0)));
And you classify that as a JDBC problem because later in the method there's some JDBC code? Well, anyway, apart from looking in the wrong place for the problem, all that means is that the getValueAt() method doesn't return an Integer object, so you can't cast it to an Integer.
And your proposed fix doesn't compile because getValueAt is declared to return an Object. If you want to use it as a String -- which it is, as you know -- then you need to cast it to String before passing it to the parseInt method.