Revert "这个项目用于存放我对java学习的记录"

This reverts commit 920be628d741bf2551966543a077dba659bb6278.
Revert "Revert "这个项目用于存放我对java学习的记录""

This reverts commit ae571502e000d7a6dbd1ba230f7bfc516d3108b3.