Question

I have a class, lets call it ‘Words’, that reads a file and creates a list of strings.

I then have a class, ‘Items’, that creates a list of ‘description’ objects, each description object needs access to the list from ‘Words’.

Since the ‘Word’ list reads a file, I obviously don’t want to create that list for each ‘description’ object. So what would be the best way of accessing that list?

Should I just create a function getList() from ‘Words’ and pass it to ‘Items’ constructor, then pass it again to each ‘description’? or is there a better way? If I do that, then I would also want to make sure it is only a reference to the list and not a copy since the ‘Words’ list can get huge.

I am relatively new to java and any help would be appreciated.

Answer 1

You need to create a class that pupulate the List of String object (singleton), call that singleTon method in constructor of description class to assign reference of list to the description object.

public class Words
{
   private static ArrayList<String> words;
   public static ArrayList<String> getWords() 
   {
      if(words==null) 
        {
          words=new ArrayList<String>();
          //read strings from the file and add them into list
        }
      return words;
    }
}

In description class,

public class Description
{
   private String desc;
   private ArrayList<String> words;

   public Description(String desc) 
    {
        this.desc=desc; 
        this.words=Words.getList();
     }
}