GET       /companies    #获取company列表
GET       /companies/1  #获取某个具体company
GET       /companies/1/employees  #获取某个具体company下所有employee列表
GET       /companies/page/1/pageSize/5  #分页查询，page等于1，pageSize等于5
POST      /companies    #增加一个company
PUT       /companies/1  #更新某个company
DELETE    /companies/1  #删除某个company以及名下所有employees

GET       /employees    #获取employee列表
GET       /employees/1  #获取某个具体employee
GET       /employees/page/1/pageSize/5  #分页查询，page等于1，pageSize等于5
GET       /employees/male   #筛选出所有男性Employee
POST      /employees    #增加一个employee
PUT       /employees/1  #更新某个employee
DELETE    /employees/1  #删除某个employee