java对List的优雅排序

1、准备排序的数据

List<Student> students = new ArrayList<>();
students.add(new Student(1,"z1",25));
students.add(new Student(12,"z2",26));
students.add(new Student(9,"z3",27));
students.add(new Student(4,"z4",28));
students.add(new Student(1,"z5",29));

2，java8之前对集合排序

//java8之前的排序
Collections.sort(students,new ComparatorChain<Student>(){
     public int compare(Student s1, Student s2) {
          return s1.getIndex().compareTo(s2.getIndex());
     }
});
students.forEach(s->{
     System.out.println(s.toString());
});

结果：

Student{index=1, name='z1', age=25}
Student{index=1, name='z5', age=29}
Student{index=4, name='z4', age=28}
Student{index=9, name='z3', age=27}
Student{index=12, name='z2', age=26

3，java8对集合优雅排序

（1）

studentList.sort((Student s1,Student s2)->s1.getIndex().compareTo(s2.getIndex()));
studentList.forEach(s -> {
　　　System.out.println(s.toString());
});

(2)

Collections.sort(studentList, Comparator.comparing(Student::getIndex));
studentList.forEach(s -> {
    System.out.println(s.toString());
});