Object内部方法及通用接口方法解析

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1. 比较器

两种方式实现比较器：

a：实现Comparable<T>接口
b：实现Comparator<T>接口

public class CompareTest {    @Test    public void testCompare() {        Student a = new Student(1, "b");        Student b = new Student(2, "c");        Student c = new Student(2, "a");        List<Student> list = new ArrayList<>();        list.add(a);        list.add(b);        list.add(c);        //第一张方法排序        Collections.sort(list);        //第二种方法排序        Compare compare = new Compare();        Collections.sort(list, compare);        System.out.println(new Gson().toJson(list));    }    private class Student implements Comparable<Student> {        int code;        String name;        public Student(int code, String name) {            this.code = code;            this.name = name;        }        @Override        public int compareTo(Student o) {            if (this.code != o.code)                return this.code - o.code;            return o.name.compareTo(this.name);        }    }    private class Compare implements Comparator<Student> {        @Override        public int compare(Student s1, Student s2) {            if (s1.code != s2.code)                return s1.code - s2.code;            return s1.name.compareTo(s2.name);        }    }}

遵守以下限制条件：自反性、对称性、传递性
注：强烈建议 ( x.compareTo(y) == 0 ) == ( x.equal(y) )

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