java | Comparable 接口

Comparator接口源码：

public interface Comparator<T> {
    int compare(T var1, T var2);
}

Arrays.sort()方法需要传入一个数组，和一个实现Comparator接口类的实例。
如将学生数组按照分数进行排序：

// 定义学生类
class Student{
    public int scores;
    private String name;
    public Student(String name, int scores){
        this.name = name;
        this.scores = scores;
    }
}

比较器类：

// 定义继承Comparator接口的实现类
class com implements Comparator<Student>{
    @Override
    // 重写compare方法
    public int compare(Student t1, Student t2) {
        return t1.scores - t2.scores;
    }
}

测试类：

public class studentTest {
    public static void main(String[] args) {
        Student[] students = new Student[2];
        students[0] = new Student("小红",101);
        students[1] = new Student("小明",100);
        Arrays.sort(students, new com());
    }
}

比较器也可写成匿名内部类的形式：

public class studentTest {
    public static void main(String[] args) {
        Student[] students = new Student[2];
        students[0] = new Student("小红",101);
        students[1] = new Student("小明",100);
        Arrays.sort(students, new Comparator<Student>() {
            @Override
            // 重写compare方法
            public int compare(Student t1, Student t2) {
                return t1.scores - t2.scores;
            }
        });
    }
}