请教类型转换问题.java.lang.NumberFormatException 异常, 谢谢！

public void comAccount(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {

    String b = req.getParameter("balance");     
    NewCustomer customer = new NewCustomer();

    DAOFactory daoFactory = DAOFactory.getDAOFactory(DAOFactory.ORACLE);
    NewCustomerDAO newcustomerDao = daoFactory.getCustomerDAO();

    newcustomerDao.heZhangJiSuan(customer);
    String a = customer.getBalance();
    System.out.println("a=="+a);

    java.util.Vector error = new java.util.Vector();
    int x,y;
    x = Integer.parseInt(b); [color=red]//程序执行到这里报异常

//java.lang.NumberFormatException: For input string: "200.00"[/color] y = Integer.parseInt(a);
if( x>y )
{
int c = x - y;
error.add("已扣除费用"+c+"RMB");
req.setAttribute("errorss", error);
}else{
error.add("账户余额不足,请充值!");
req.setAttribute("errors", error);

}
String address = "/page/comAccount.jsp";
req.getRequestDispatcher(address).forward(req, resp);

}

不能这样用，如果确定这里输入的都是整数，那么可以先用Double.parseDouble(String string)方法来转成double类型
下面代码测试通过
[code="java"]
String s="200.00";
int i=(int)Double.parseDouble(s);
System.out.println(i);
[/code]

如果数据可能不是整数，建议修改程序的其它部分

金额信息一般都是Double类型

建议直接将int改为Double,然后包装类方法也跟着一起换成Double.parseDouble()