相关疑难解决方法(0)

什么问题/陷阱,必须重写时,必须考虑equals和hashCode？

当我运行以下代码时:

  Student student1 = new Student("Billy", 13);
  Student student2 = new Student("Bob", 12);
  Student student3 = new Student("Belle", 11);
  Student student4 = new Student("Barry", 10);
  Student student5 = new Student("Brian", 10);
  Student student6 = new Student("Bane", 13);
  Collection<Student> students = new HashSet<Student>();
  students.add(student1);
  students.add(student2);
  students.add(student3);
  students.add(student4);
  students.add(student5);
  students.add(student6);
  for(Student student : students)
  {
    String name = student.getName();
    System.out.println(name);
  }

它将打印出我的学生对象的名称列表.现在我想按字母顺序排列.我认为它就像使用TreeSet或SortedSet一样简单.

像这样:

 Student student1 = new Student("Billy", 13);
 Student student2 = new Student("Bob", 12);
 Student student3 = new Student("Belle", 11);
 Student …