Java编写的一个小通讯录系统，数据库采用mysql,有查询、添加、删除等基本功能。-Java written in a small address book, database using mysql, there are queries, add, delete and other basic functions.

教室管理系统。java语言开发，mysql数据库。学生可以选择上课教室，具有查询删除功能.-Classroom management system. Java language development, mysql . Students can choose to classrooms, with query delete function.