用Java编写的记事本，本人的课程设计，可以同时编辑多个文档，实现了记事本的一些常用的功能，如撤销，剪切，复制，粘贴等-Written in Notepad using Java, my curriculum design, you can edit multiple documents at the same time to realize some of the commonly used Notepad features, such as revocation, cut, copy, pa