Java compareTo用法详解

public interface Comparable<T> {
    public int compareTo(T o);
}

public final class String
    implements java.io.Serializable, Comparable<String>, CharSequence {
    }

public int compareTo(String anotherString) {
    int len1 = value.length;
    int len2 = anotherString.value.length;
    int lim = Math.min(len1, len2);
    char v1[] = value;
    char v2[] = anotherString.value;
    int k = 0;
    while (k < lim) {
        char c1 = v1[k];
        char c2 = v2[k];
        if (c1 != c2) {
            return c1 - c2;
        }
        k++;
    }
    return len1 - len2;
}

public class Student implements Comparable<Student> {
  private String name;
  private int age;
  // 构造函数和其他方法
  @Override
  public int compareTo(Student other) {
      // 比较规则：按年龄升序排序
      return this.age - other.age;
  }
}

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class Main {
    public static void main(String[] args) {
        List<Student> students = new ArrayList<Student>();
        students.add(new Student("A", 20));
        students.add(new Student("B", 18));
        students.add(new Student("C", 22));
        // 使用Collections.sort进行排序
        Collections.sort(students);
        for (Student student : students) {
            System.out.println(student.getName() + ": " + student.getAge());
        }
    }
}