字符串应用与面向对象程序设计,编写一个Java项目，模拟一次包括老师备课，同学上课，布置作业和做作业的课堂教学过程。作业为判断字符串是否为2-重复串及其他字符串操作内容。-String object oriented application programming, write a Java program, including teacher preparation time simulation, the students in class, assignments and homework in the classroom teaching process. Job is to determine whether the string is 2- duplicate content string and other string operations.