Student学生表
getId()setId()
JDBCUtilsByDruid连接数据库
getConnection()close()
Teacher教师表
StudentService学生登录
getStudentByIDAndPwd()
StudentDAO
Grade成绩表
Recorder文件操作
getGrades_list_write()keepRecord()
Utility工具类
readChar()readInt()readDouble()
TeacherService教师登录
getTeacherByIDAndPwd()
View主页面
InsertGrade() delGrade()modifyGrade()allGrade()
TeacherDAO
BasicDAO修改数据库数据
update()orderBy()queryMulti()
GradeDAO
GradeService添加 删除修改
addGrade()cutGrade()
