java.lang.ClassCastException one class to other

I am using the following code to execute while hit the submit button, I am getting the following error and not sure where the mistake was, can anyone gimme a suggest here?

private ModelAndView save(HttpServletRequest request,
        HttpServletResponse response) throws Exception {
    try {
        User user = userService.getLoggedInUser(request);
        SimpleDateFormat formatter = new SimpleDateFormat("dd-MMM-yyyy");

        String funderName = request.getParameter("funderId");
        Long funderId = Long.parseLong(funderName);
        String amount = request.getParameter("amount");
        Long amountLong = Long.parseLong(amount);

        String purpose = request.getParameter("purpose");
        Long purLong = Long.parseLong(purpose);
        String from = request.getParameter("from");
        Date fromDate = formatter.parse(from);
        String to = request.getParameter("to");
        Date toDate = formatter.parse(to);

        FundsDetails fundsDetails = new FundsDetails();
        fundsDetails.setIdStaticFunder(funderId);
        fundsDetails.setFundsPurposeId(null);
        fundsDetails.setFundAmount(amountLong);
        fundsDetails.setStartDate(fromDate);
        fundsDetails.setEndDate(toDate);
        fundsDetails.setLastModifiedBy(user.getId());
        funderRepository.createFund(fundsDetails);

        FundsProductPurpose fundsProductPurpose = new FundsProductPurpose();
        fundsProductPurpose.setIdFundsDetails(fundRepository.getFundsList().get(0).getId());
        fundsProductPurpose.setIdStaticLoanPurpose(purLong);
        fundsProductPurpose.setLastModifiedBy(user.getId());
        funderRepository.createFundProduct(fundsProductPurpose);

        List<FundsProductPurpose> fppList = funderRepository.getFundsList();
        FundsProductPurpose fpp = fppList.get(0);

        //Integer val = fpp.getId();
        //System.out.println("*funderRepository.getFundsList().get(0).getId().longValue()*"+val);

        FundsDetails fd = fundRepository.getFundsList().get(0);
        System.out.println("FundsDetails fd***"+fundRepository.getFundsList().get(0).getFundsPurposeId());


        /*fd.setFundsPurposeId(val);
        commonRepository.update(fd);*/          

        return doMapping("result", "Funder details added successfully",
                request);
    } catch (Exception e) {
        e.printStackTrace();
        return doMapping("result", "Unable to add funder details", request);
    }
}

Error I am getting is,

java.lang.ClassCastException: com.mmf.model.FundsDetails cannot be cast to com.mmf.model.FundsProductPurpose
    at com.mmf.controllers.SaveFundsController.save(com.mmf.controllers.SaveFundsController:98)