NP：可能的空指针解除引用（NP_NULL_ON_SOME_PATH）

Question

执行非空检查时，我在以下代码中获得了“可能的空指针取消引用dssResponseStatus”。最初为dssResponseStatus分配了一个空值，但它已被用于从不同的方法获取状态。
    我该如何解决这个问题。帮助人

    DSSAdminResponseBean createIdAdminBean = new DSSAdminResponseBean();
        String dssResponseStatus = null;

        // To overcome cupcake overriding
        userCupcakeValue = (String) request.getSession().getAttribute(
                DSSAdminGuiConstants.USERCUPCAKE);
        DSSADMINLogger.log(
                DEBUG,
                "userCupcakeValue :"
                + MaskingSecuredData
                .maskingSecuredData(userCupcakeValue));

        ArrayList createIdList = createIdService.getCreateIdManager(
                createIdBean, userCupcakeValue);
        dssResponseStatus = DSSCheckResponseStatus.toCheckResponseStatus(
                createIdAdminBean, createIdList);

        DSSADMINLogger.log(DEBUG, "dssResponseStatus :" + dssResponseStatus);
        performAudit(request, createIdBean, dssResponseStatus);
        // When the dssResponseStatus gets the error value as connectionError,
        // then it will be forward to error Page

//getting the error in this line        if (dssResponseStatus != null
                && !dssResponseStatus
                .equals(DSSAdminGuiConstants.DSS_SUCCESS_STATUS)
                && !dssResponseStatus
                .equalsIgnoreCase(DSSAdminGuiConstants.CONNECTION_ERROR)) {
            String message = ErrorMessages.errorCodes(dssResponseStatus,
                    DSSAdminGuiConstants.CREATEID);
            DSSADMINLogger.log(ERROR,
                    "DSSResponseServer ErrorStatus for CreateId API :"
                    + message);
            return new ModelAndView(DSSAdminGuiConstants.DSSADMINCREATEID,
                    DSSAdminGuiConstants.RESPONSE_ERROR, message);
        } else if (dssResponseStatus
                .equalsIgnoreCase(DSSAdminGuiConstants.CONNECTION_ERROR)) {
            DSSADMINLogger.log(ERROR, "DSSResponseSerever ErrorStatus :"
                    + dssResponseStatus);
            return new ModelAndView(DSSAdminGuiConstants.DSSADMINERRORMESSAGE,
                    DSSAdminGuiConstants.ERROR_STATUS, 2);
        } else {
            DSSADMINLogger.log(INFO, "Leaving getCreateIdResponse Method");
            return new ModelAndView(DSSAdminGuiConstants.DSSADMINGETID,
                    DSSAdminGuiConstants.CREATEID_ATTRIBUTES, createIdList);

        }


}