如何对arraylist执行一系列排序操作（多个排序条件） [英] How to perform a series of sort operation on arraylist (multiple sort criteria)

问题描述

我有一个arrayList的对象，我想对这个列表运行一系列的排序操作。我想先按名字排序，如果两个名字相同，例如通过id排序。

如何实现它？

这是我的代码

 比较器< Ticket> ; mc; 
 mc = new TicketIdComparator（）; 
 Collections.sort（tickets，mc）; 
 
 
 final class TicketIdComparator implements Comparator< Ticket> 
 
 {
 
 @Override 
 public int compare（Ticket ticket1，Ticket ticket2）{
 String TicketId1 =（（Ticket）ticket1）.getNumber ）; 
 String TickedId2 =（（Ticket）ticket2）.getNumber（）; 
 
 int num1 = Integer.parseInt（TicketId1）; 
 int num2 = Integer.parseInt（TickedId2）; 
 
 if（num1  return 1; 
 if（num1> num2）
 return -1; 
 return 0; 
 
 
 
} 
} 
  

这个代码排序列表由 id ，但是我想再次排序 name

解决方案

  Collections.sort（myList，new Comparator（）{
 
 @Override 
 public int compare（Object o1，Object o2）
 {
 //这里写你的订购代码
 return 0; 
} 
 
} 
  

只需填写所需的比较代码，Java就会为您处理排序。 p>

编辑更新问题：

 比较器< Ticket> mc; 
 mc = new TicketIdComparator（）; 
 Collections.sort（tickets，mc）; 
 
 
 final class TicketIdComparator implements Comparator< Ticket> 
 
 {
 
 @Override 
 public int compare（Ticket ticket1，Ticket ticket2）{
 String TicketId1 =（（Ticket）ticket1）.getNumber ）; 
 String TickedId2 =（（Ticket）ticket2）.getNumber（）; 
 
 int num1 = Integer.parseInt（TicketId1）; 
 int num2 = Integer.parseInt（TickedId2）; 
 
 if（num1  return 1; 
 else if（num1> num2）
 return -1; 
 else 
 return ticket1.getName（）。compare（ticket2.getName（））; 
} 
} 
  

I have an arrayList of objects and I want to run a series of sort operations on this list. I would want to sort them by first by name, and if two names are same than sort them by id, for example.

How can i implement it?

This is my code

Comparator<Ticket> mc;
mc = new TicketIdComparator();
Collections.sort(tickets, mc);


final class TicketIdComparator implements Comparator<Ticket>

{

    @Override
    public int compare(Ticket ticket1, Ticket ticket2) {
        String TicketId1 = ((Ticket) ticket1).getNumber();
        String TickedId2 = ((Ticket) ticket2).getNumber();

        int num1=Integer.parseInt(TicketId1);
        int num2 =Integer.parseInt(TickedId2);

        if (num1<num2)
            return 1;
        if (num1>num2)
            return -1;
        return 0;



    }
}

This code sorting list by id, but again i want to sort on name

解决方案

  Collections.sort(myList, new Comparator() {

     @Override
     public int compare(Object o1, Object o2)
     {
        // write your ordering code here
        return 0;
     }

  });

Just fill in the code for the comparison you want and Java will handle the sorting for you.

Edit for updated question:

Comparator<Ticket> mc;
mc = new TicketIdComparator();
Collections.sort(tickets, mc);


final class TicketIdComparator implements Comparator<Ticket>

{

    @Override
    public int compare(Ticket ticket1, Ticket ticket2) {
        String TicketId1 = ((Ticket) ticket1).getNumber();
        String TickedId2 = ((Ticket) ticket2).getNumber();

        int num1=Integer.parseInt(TicketId1);
        int num2 =Integer.parseInt(TickedId2);

        if (num1<num2)
            return 1;
        else if (num1>num2)
            return -1;
        else
            return ticket1.getName().compare(ticket2.getName());
    }
}

这篇关于如何对arraylist执行一系列排序操作（多个排序条件）的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！