カスタムTreeSetでのソート
3174 ワード
最初のコードの例:
2つ目のコードの例:
テストコード(1つ目と2つ目が一緒に書かれています):
public class User implements Comparable<User> {
private String name;
private int age;
private int orderNumber;
public User(String name, int age, int orderNumber) {
this.name = name;
this.age = age;
this.orderNumber = orderNumber;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public int getOrderNumber() {
return orderNumber;
}
public void setOrderNumber(int orderNumber) {
this.orderNumber = orderNumber;
}
@Override
public int compareTo(User other) {
if (this.getOrderNumber() == other.getOrderNumber()) {
return this.getAge() - other.getAge();
}
return this.getOrderNumber() - other.getOrderNumber();
}
@Override
public String toString() {
return "User [name=" + name + ", age=" + age + ", orderNumber=" + orderNumber + "]";
}
}
2つ目のコードの例:
public class Student {
private String name;
private int score;
public Student(String name, int score) {
super();
this.name = name;
this.score = score;
}
@Override
public String toString() {
return "Student [name=" + name + ", score=" + score + "]";
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getScore() {
return score;
}
public void setScore(int score) {
this.score = score;
}
}
public class StudentComparator implements Comparator<Student>{
@Override
public int compare(Student s1, Student s2) {
return s2.getScore() - s1.getScore();
}
}
テストコード(1つ目と2つ目が一緒に書かれています):
public class TestTreeSet {
public static void main(String[] args) {
TreeSet<User> set = new TreeSet<>();
User user1 = new User("Tom", 25, 3);
User user2 = new User("Jack", 28, 2);
User user3 = new User("Mike", 20, 3);
User user4 = new User("John", 30, 1);
User user5 = new User("Jill", 50, 0);
set.add(user1);
set.add(user2);
set.add(user3);
set.add(user4);
set.add(user5);
System.out.println(set);
Set<Student> studens = new TreeSet<>(new StudentComparator());
Student s1 = new Student("Tom", 80);
Student s2 = new Student("Jack", 95);
Student s3 = new Student("Mike", 60);
Student s4 = new Student("John", 75);
Student s5 = new Student("Jill", 100);
studens.add(s1);
studens.add(s2);
studens.add(s3);
studens.add(s4);
studens.add(s5);
System.out.println(studens);
}
}