java - 防止Java中具有多个字段的重复数据集

Question

我目前正在使用一个程序，每次运行该程序时都会实例化三个数字变量。例如:

(companyID, groupID, hostID)

The 1st time when I run it
(int companyID = 1; int groupID = 1, int hostID = 1)

2nd time
(1, 1, 1)

3rd time
(1, 1, 1)

4th
(1, 2, 1)

5th
(6, 4, 3)

...

有没有一种方法可以让我每次运行程序时都将这三个数字保存在数据集中，同时防止数据集中存储相同顺序的重复数字？在上例中，仅存储 1, 1, 1 的一个实例。

所以数据集中存储的最终结果只有(1,1,1),(1,2,1),(6,4,3)。

谢谢。

Answer 1

试试这个:

代码

import java.util.ArrayList;
import java.util.List;

public class DatasetUnique {

    public static void main(String args[]){

        //  Data to insert
        int[] one =     {1,2,3};
        int[] two =     {2,3,4};
        int[] three =   {1,2,3};
        int[] four =    {7,8,9};
        int[] five =    {2,3,4};

        //  Data inserted
        List<dataSet> allContent = new ArrayList<>();

        //  1 - Insert data
        insert(new dataSet(one), allContent);
        insert(new dataSet(two), allContent);
        insert(new dataSet(three), allContent);
        insert(new dataSet(four), allContent);
        insert(new dataSet(five), allContent);

        //  2 - Print data
        System.out.println(allContent.toString());

    }

    //  Insert a dataset inside list if doesnt exists
    private static void insert(dataSet dataSetToInsert, List<dataSet> allContent){
        if(allContent.size() == 0){
            allContent.add(dataSetToInsert);
        }else{
            for(dataSet ds: allContent){
                if(dataSetToInsert.equals(ds)){
                    return;
                }               
            }
            allContent.add(dataSetToInsert);
        }
    }

    //  Class for each dataSet
    private static class dataSet{

        int firstNumber;
        int secondNumber;
        int thirdNumber;

        public dataSet(int[] dataSet) {
            super();
            this.firstNumber = dataSet[0];
            this.secondNumber = dataSet[1];
            this.thirdNumber = dataSet[2];
        }

        @Override
        public boolean equals(Object obj) {
            if (this == obj)
                return true;
            if (obj == null)
                return false;
            if (getClass() != obj.getClass())
                return false;
            dataSet other = (dataSet) obj;          
            if (firstNumber != other.firstNumber)
                return false;
            if (secondNumber != other.secondNumber)
                return false;
            if (thirdNumber != other.thirdNumber)
                return false;
            return true;
        }

        @Override
        public String toString() {
            return "\n" + firstNumber + " " + secondNumber + " "+ thirdNumber + "\n";
        }       
    }


}

输出

[
1 2 3
, 
2 3 4
, 
7 8 9
]