java - Human 不是抽象的，不会覆盖抽象方法 compareTo(Human) .solution？

Question

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

    public Human(String givenName, int age) {
        this.name = givenName;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }

    public String introduce() {
        return "Hey! I'm " + name + " and I'm " + age + " years old.";
    }

    public int CompareTo(Human h1, Human h2) {
            int hum1 = h1.getAge();
            int hum2 = h2.getAge();
            System.out.println(hum1 - hum2);
    }
}

此代码使用 age 参数对 arraylist 进行排序，并出现此错误消息

./Human.java:6: error: Human is not abstract and does not override abstract method compareTo(Human) in Comparable public class Human implements Comparable

这是怎么回事？请帮忙。

Answer 1

你想改变:

public int CompareTo(Human h1, Human h2)

到:

public int compareTo(Human h_other)

两件事:首先，“c”是小写的。其次，compareTo 方法将 this 与另一个 Human 进行比较，因此它等同于(使用您的旧代码):

public int compareTo(Human h_other) {
    return CompareTo(this, other);
}