NullPointException应该算是每一个码农都很熟悉的家伙了吧?谁的代码不曾抛过几个空指针异常呢... 比如:你写了段如下的代码: public void getCompanyFromEmployee() { Employee employee = getEmployee(); Company company = employee.getTeam().getDepartment().getCompany(); System.out.println(company); } private Employee …