关于Iterator的next()方法,该如何处理

Iterator<T_Tms_TransIbp> iterator  = list.iterator();          while(iterator.hasNext()){                if(iterator.next().getCompanycode()==null){                   error.append("接口表中Companycode的必录项有空,");                                 }               else if(iterator.next().getSalechannelcode()==null){                   error.append("接口表中Salechannelcode的必录项有空,");                                }               if(iterator.next().getBillnumber()==null){                   error.append("接口表中Billnumber的必录项有空,");                                  }               if(iterator.next().getBillbooknumber()==null){                   error.append("接口表中Billbooknumber的必录项有空,");                                 }               if(iterator.next().getSeragentcode()==null){                   error.append("接口表中Seragentcode的必录项有空,");                                 }               if(iterator.next().getPhone()==null){                   error.append("接口表中Phone的必录项有空,");                                 }               if(iterator.next().getSersectioncode()==null){                   error.append("接口表中Sersectioncode的必录项有空,");                                   }               if(iterator.next().getSerteamcode()==null){                   error.append("接口表中Serteamcode的必录项有空,");                                  }               if(iterator.next().getPolicyholdername()==null){                   error.append("接口表中Policyholdername的必录项有空,");                                   }               if(iterator.next().getInsurecode()==null){                   error.append("接口表中Insurecode的必录项有空,");                                   }               if(iterator.next().getCerttypecode()==null){                   error.append("接口表中Certtypecode的必录项有空,");                                }               if(iterator.next().getChargetypecode()==2&&iterator.next().getBankcode()==null){                   error.append("CHARGETYPECODE=2转帐时,BANKCODE不能为空,");                                  }               if(iterator.next().getChargetypecode()==2&&iterator.next().getAccountname()==null){                   error.append("CHARGETYPECODE=2转帐时,Accountname不能为空,");                                   }               if(iterator.next().getChargetypecode()==2&&iterator.next().getAccounts()==null){                   error.append("CHARGETYPECODE=2转帐时,Accounts不能为空,");                                  }               if(iterator.next().getChargetype()==3&&iterator.next().getPeriodofvalidity()==null){                   error.append("ChargeType为信用卡时,PERIODOFVALIDITY, 信用卡缴费不能为空,");                                  }                if(iterator.next().getChargetype()==3&&iterator.next().getPeriodofvalidity().matches("^\\d{4}$")){                   error.append("ChargeType为信用卡时,信用卡有效期至 格式不正确,");                                   }                if (iterator.next().getChargetype()==3//?    中信信用卡转帐时,Ensuremodel,计划型号必录                    &&iterator.next().getBrushbankcode().equals("017")                    &&iterator.next().getEnsuremodel()==null){                   error.append("中信信用卡转帐时,Ensuremodel,计划型号不能为空");                                                             }