public static void main(String[] args) { int selectNumber = 2;//分组数量 Set<SignStudentEntity> students = new HashSet<>(); for(int non=1; non<=10; non++){ students.add(new SignStudentEntity(non)); } int size = students.size(); //容量 int j = size / selectNumber; //取模 int k = size % selectNumber; //取余 int m = 1; int i = 1; for(SignStudentEntity signStudent : students){ if(i <= j * m + k){ signStudent.setGroupNumber(m); }else{ m+=1; signStudent.setGroupNumber(m); } i+=1; } System.out.println(size / selectNumber); //4 System.out.println(size % selectNumber); //1 System.out.println(students); }