两种方法：一种是在类内部实现；一种是在类外部定义一个类的可比器

    package in;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;

/**
 * Created by S_eve on 2017/6/16.
 * 关于排序的两个接口
 */
public class TestJiakou {
    public static void main(String[] args) {
        //第一种方法
        Student[] students1 = new Student[7];
        students1[0] = new Student(7, "hah");
        students1[1] = new Student(3, "hah");
        students1[2] = new Student(5, "hah");
        students1[3] = new Student(1, "hah");
        students1[4] = new Student(4, "hah");
        students1[5] = new Student(2, "hah");
        students1[6] = new Student(6, "hah");
        Arrays.sort(students1);
        for(int i = 0; i < 7; i++){
            System.out.println(students1[i].toString());
        }
        System.out.println("+++++++++++++++++++++++++++++++++++++");
        //第二种
        Student1[] students2 = new Student1[7];
        students2[0] = new Student1(7, "hah");
        students2[1] = new Student1(3, "hah");
        students2[2] = new Student1(5, "hah");
        students2[3] = new Student1(1, "hah");
        students2[4] = new Student1(4, "hah");
        students2[5] = new Student1(2, "hah");
        students2[6] = new Student1(6, "hah");
        Arrays.sort(students2, new StudentComparator());
        for(int i = 0; i < 7; i++){
            System.out.println(students2[i].toString());
        }

    }

}

//第一种方法，在类内部实现Comparable
class Student implements Comparable{
    private int id;
    private String name;

    public Student(int id, String name) {
        this.id = id;
        this.name = name;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public boolean equals(Object o) {
        if(this == o)
            return true;
        if(!(o instanceof Student))
            return false;
        Student other = (Student)o;
        if(this.id == other.id && this.name.equals(other.name))
            return true;
        return false;

    }

    @Override
    public int hashCode() {
        int result = id;
        result = 31 * result + (name != null ? name.hashCode() : 0);
        return result;
    }

    @Override
    public String toString() {
        return "Student{" +
                "id=" + id +
                ", name='" + name + '\'' +
                '}';
    }

    @Override
    public int compareTo(Object o) {
        Student other = (Student)o;
        if(this.id < other.id){
            return -1;
        }else if(this.id > other.id) {
            return 1;
        }
        return 0;
    }
}

class Student1{
    private int id;
    private String name;

    public Student1(int id, String name) {
        this.id = id;
        this.name = name;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public boolean equals(Object o) {
        if(this == o)
            return true;
        if(!(o instanceof Student1))
            return false;
        Student1 other = (Student1)o;
        if(this.id == other.id && this.name.equals(other.name))
            return true;
        return false;

    }

    @Override
    public int hashCode() {
        int result = id;
        result = 31 * result + (name != null ? name.hashCode() : 0);
        return result;
    }

    @Override
    public String toString() {
        return "Student1{" +
                "id=" + id +
                ", name='" + name + '\'' +
                '}';
    }
}


//第二种定义一个类比较器
class StudentComparator implements Comparator{

    @Override
    public int compare(Object o1, Object o2) {
        Student1 other1 = (Student1)o1;
        Student1 other2 = (Student1)o2;
        if(other1.getId() < other2.getId()){
            return -1;
        }else if(other1.getId() > other2.getId()){
            return 1;
        }
        return 0;
    }
}