java - 在JAVA中为List的每个元素动态创建一个List

Question

我在一个项目中，我应该向客户展示一个元素列表，在客户选择列表中的一个元素后，我向客户展示另一个与他的选择相关的元素列表。

我对第一组元素使用了一个arrayList，我最好对另一个链表使用hashMap。

我真的不知道从哪里开始，或者我可以使用其他数据结构。

十分感谢

在这里，我发布了“New's”类的代码。实际上我在服务器端工作，我向客户展示了一个新闻列表，然后他选择了他想要阅读的新闻数量，我显示了与该特定新闻相关的所有评论。

import java.io.*;
import java.util.*;

public class News
{
    private String journalist;
    private String title;
    FileManager fm = new FileManager("NewsList.txt");
    String PCPath = fm.getPCPath();

    private ArrayList<String> newsList = new ArrayList<String>();

    public void printNewsList()
    {
        setListLenght(newsList.size());

        // print all news
        for (int i = 0; i < elencoNotizie.size(); i++)
        {
            System.out.println(newsList.get(i));
        }
    }

    /*
     * THE FOLLOWING METHOD ADDS NEWS FROM CLIENT INPUT -- EACH ELEMENT OF THIS LIST
     * SHOULD HAVE A LIST OF ITS COMMENTS (String) AND ITS VALUTATION (int) , THAT'S
     * WHY I'D NEED AN HASHMAP. EVERY TIME THE CLIENT ADDS A NEWS I SHOULD
     * DYNAMICALLY INCREAS THE HASM MAP DIMENSION TO INSTANTIATE A POSSIBILE LIST OF
     * COMMENTS FOR THAT NEWS
     */

    public void addNews(String receivedJournalis, String receivedTitle) throws IOException
            {
                FileWriter fw = new FileWriter(PCPAth+"NewsList.txt", true);
                BufferedWriter bw = new BufferedWriter(fw);

                //save input in .txt file
                bw.newLine();
                bw.write((newsList.size()+1)+") Journalist: "+receivedJournalis+" - Title: "+receivedTitle);
                bw.close(); 

                   //save input in list
                newsList.add((newsList.size()+1)+") Journalist : "+receivedJournalis+" - Title: "+receivedTitle);

                //print all news list
                System.out.println(newsList.toString());
            }

标签： javalisthashmap