public class Student implements Comparable<Student>{
  private String id;
  private String name;
  private int age;

  public Student(String id,String name,int age){
    this.id = id;
    this.name = name;
    this.age = age;
  }

  public boolean equals(Object obj){
    if(obj == null){
      return false;
    }

    if(this == obj){
      return true;
    }

    if(obj.getClass() != this.getClass()){
      return false;
    }

    Student student = (Student)obj;
    if(!student.getName().equals(getName())){
      return false;
    }

    return true;
  }

  public int compareTo(Student student) {
    return this.age - student.age;
  }

  /** 省略getter、setter方法 */
}

public static void main(String[] args){
    List<Student> list = new ArrayList<>();
    list.add(new Student("1", "chenssy1", 24));
    list.add(new Student("2", "chenssy1", 26));

    Collections.sort(list);  //排序

    Student student = new Student("2", "chenssy1", 26);

    //检索student在list中的位置
    int index1 = list.indexOf(student);
    int index2 = Collections.binarySearch(list, student);

    System.out.println("index1 = " + index1);
    System.out.println("index2 = " + index2);
  }

index1 = 0

index2 = 1