initial
add three //lab4 mark in .java
add one //lab4 mark
Revert "add one //lab4 mark"

This reverts commit 13c0f055f25c5b9991f51b6c9e1e4db9d0db84ea.
Merge branch 'master' of https://github.com/yezhejack/lab4_lab2

Conflicts:
	src/Book/ABook.java
	src/Book/BookManage.java
	src/com/company/listener/SaeListener.java