bootstrp 抽样方法，可以用于进行一些统计量误差的估计-bootstrp sampling methods, can be used to carry out some statistics of the estimated error

一个完整的springmvc应用，后端是spring+springmvc+mybatis+mysql 前端 bootstrap(A complete springmvc application, the back end is the spring+springmvc+mybatis+mysql front-end bootstrap)