java接口實現Comparable接口比較對象具體屬性

1.解釋一下Comparable怎麼用： 

package com.hy.object.customerMessageManagement;

/**
 * @author MSI-PC
 * @date 2020-06-21 17:45
 */

public class MyArrays {
    public void sort(Object[] arr){
        for(int i=1;i<arr.length;i++){
            for(int j=0;j<arr.length-i;j++){
               Comparable pre = (Comparable) arr[j]; //如果這個位置運行沒有報錯，說明arr[j]這個元素實現了Comparable接口
               if(pre.compareTo(arr[j+1])>0){
                   Object temp =arr[j];
                   arr[j] =arr[j+1];
                   arr[j+1]=temp;
               }
            }
        }
    }
}

2.通過僱員繼承Comparable接口的例子來說明排序

package com.hy.object.customerMessageManagement.comparable;

/**
 * @author MSI-PC
 * @date 2020-06-21 18:02
 */

public class Employee implements Comparable{
    private String name;
    private double salary;

    public Employee() {}

    public Employee(String name, double salary) {
        this.name = name;
        this.salary = salary;
    }

    public String getName() {
        return name;
    }

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

    public double getSalary() {
        return salary;
    }

    public void setSalary(double salary) {
        this.salary = salary;
    }

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

    public int compareTo(Object o) {
        Employee emp = (Employee)o;
        if(this.salary > emp.salary){
            return 1;
        }else if(this.salary < emp.salary){
            return -1;
        }
        return 0;
    }
}

package com.hy.object.customerMessageManagement.comparable;

import java.util.Arrays;

/**
 * @author MSI-PC
 * @date 2020-06-21 18:07
 */

public class TestEmployee {
    public static void main(String args[]){
      Employee[] arr = new Employee[5];
      arr[0] = new Employee("張1",1034);
      arr[1] = new Employee("張2",14645);
      arr[2] = new Employee("張3",1566544);
      arr[3] = new Employee("張4",153423);
      arr[4] = new Employee("張5",14);
        Arrays.sort(arr);
        for(int i=0;i<arr.length;i++){
            System.out.println(arr[i]);
        }
    }

}