在不使用Collections.sort的情况下对ArrayList中的对象进行排序

我想使用我自己的排序方法而不是 Collections.sort ，以便我可以修改我的程序以了解其他种类，泛型和 ArrayList 更好。

I would like to use my own sorting method instead of Collections.sort so that I can tinker around with my program to understand other sorts, generics, and ArrayLists better.

我有一个有员工编号成员的员​​工类。我知道如何制作一个 ArrayList 的Employee对象，但是你能解释一下我如何打印和排序它们吗？我从排序常规数组开始，并希望对Employee对象的ArrayList（员工编号）执行相同的操作。我无法理解如何打印对象的ArrayLists并对它们进行排序。

I have an employee class that has an employee number member. I know how to make an ArrayList of Employee objects, but could you explain how I could print and sort them? I started off by sorting a regular array and wanted to do the same with an ArrayList of Employee objects (the employee number). I'm having trouble understanding how to print ArrayLists of objects and sorting them.

package dataStructures;

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

public class SortPractice {

    public static void main(String[] args) {
        int[] nums = {5,4,3,2,1};

        System.out.println(Arrays.toString(nums));

        BubbleSort1(nums);

        ArrayList<Employee> empList = new ArrayList<Employee>();

        for (int i=0; i<10; i++) {
            empList.add(new Employee(10-i));

        }

        BubbleSort(empList);  //This method doesn't work. I need help here.

    }


public static void BubbleSort (int[] A) {   //I included this because I know it works.
        int temp = 0;
        int firstLoopCount = 0;
        int SecLoopCount = 0;
        for (int i=0; i< A.length-1; i++) {
            firstLoopCount++;
            System.out.println(Arrays.toString(A) + i + " << First Loop interation");

           for (int j=0; j<A.length-1; j++) {
               if (A[j] > A[j+1]) {
                    temp = A[j];
                    A[j] = A[j+1];
                    A[j+1] = temp;
                }
               SecLoopCount++;
             System.out.println(Arrays.toString(A) + j + "  << Second Loop Interation");

           }
        }
        System.out.println((firstLoopCount+SecLoopCount));


    }

    public static void BubbleSort (ArrayList<Employee> empList) { //I tried to use the same
        int temp = 0;                                             //approach just with the List
        int firstLoopCount = 0;
        int SecLoopCount = 0;
        for (int i=0; i<empList.size()-1; i++) {
            firstLoopCount++;
            System.out.println(Arrays.toString(empList) + i + " << First Loop interation");

           for (int j=0; j<empList.size()-1; j++) {
               if (empList.get(j) > empList.get(j+1)) {    //I get errors here in Eclipse and 
                    temp = A[j];                           //up above when I use toString
                    A[j] = A[j+1];
                    A[j+1] = temp;
                }
               SecLoopCount++;
             System.out.println(Arrays.toString(A) + j + "  << Second Loop Interation");

           }
        }
        System.out.println((firstLoopCount+SecLoopCount));


    }

这是员工类。它有其他的getter和setter但我没有包含它们。

Here is the employee class. It has other getters and setters but I didn't include them.

package dataStructures;

 public class Employee {

     private int empNum;
     private String firstName;
     private String LastName;
     private String email;

     public Employee(int empNum) {
         this.empNum = empNum;
     }


     public String toString(){
         return " "+ empNum + ",";

     }
     public Employee() {

     }

     public int getEmpNum() {
        return empNum;
    }
    public void setEmpNum(int empNum) {
        this.empNum = empNum;
    }