MaplargeCatg = largeList.stream().collect(Collectors.toMap(MdCustomerCatg::getCatgCode,s->s,(k1,k2)->k1)); Map salesmanMap = salesmanList.stream().collect(Collectors.toMap(s->s.getCustomerCode()+s.getSalesmanCode(),l->l,(k1,k2)->k1));``

MaplargeCatg = largeList.stream().collect(Collectors.toMap(MdCustomerCatg::getCatgCode,s->s,(k1,k2)->k1)); Map salesmanMap = salesmanList.stream().collect(Collectors.toMap(s->s.getCustomerCode()+s.getSalesmanCode(),l->l,(k1,k2)->k1));``