流式函数开发、lambda表达式
java8 .stream().map().collect()用法
https://blog.csdn.net/shine_guo_star/article/details/94383319?utm_medium=distribute.pc_relevant.none-task-blog-title-1&spm=1001.2101.3001.4242
https://blog.csdn.net/shine_guo_star/article/details/94383319?utm_medium=distribute.pc_relevant.none-task-blog-title-1&spm=1001.2101.3001.4242