public?void?testsort4()?{
????List<Student>?studentList?=?new?ArrayList<Student>();
????List<String>?idList?=?new?ArrayList<String>();
????Random?random=new?Random();
????for?(int?i=0;i<3;i++){
????????StringBuilder?stringBuilder;
????????do?{stringBuilder=new?StringBuilder();
????????????Integer?num=random.nextInt(1000);
????????????String?str=num.toString();
????????????stringBuilder.append(str);
????????}while?(idList.contains(stringBuilder));
????????idList.add(stringBuilder.toString());
????}
????studentList.add(new?Student(idList.get(0),?"Mike"));
????studentList.add(new?Student(idList.get(1),?"Angela"));
????studentList.add(new?Student(idList.get(2),?"Peter"));
????System.out.println("------------------排序前-----------------------------");
????for?(Student?a?:?studentList)?{
????????System.out.println("學生："?+?a.id?+?","?+?a.name);
????}
????System.out.println("---------------按ID排序后-----------------------------");
????Collections.sort(studentList);
????for?(Student?a?:?studentList)?{
????????System.out.println("學生："?+?a.id?+?","?+?a.name);
????}
????System.out.println("---------------按name排序后---------------------------");
????Collections.sort(studentList,new?StudentComparator());
????for?(Student?a?:?studentList)?{
????????System.out.println("學生："?+?a.id?+?","?+?a.name);
????}
}