学些dao
osUtil
Revert "学些dao"

This reverts commit c29bcc993d3851c506a38ffe6e111222492f9fe7.
Revert "osUtil"

This reverts commit 35be9063782dbee8af3544cfcc4fcbde19e40ce6.
first commit
first commit
Merge branch 'master' of https://github.com/wgou/OSDAO