java 生成树

https://blog.csdn.net/xqnode/article/details/79639106 ？？？

https://www.cnblogs.com/wangjianly/p/8486632.html?from=timeline

https://www.iteye.com/blog/ysj5125094-2283159

JAVA 把一个List转成树形结构：

https://blog.csdn.net/liangwenmail/article/details/97393817