CODEWITHSUNDEEP
javadata-structureshashmap
gcode
gcode

Reputation: 13

How to handle better data from HashMap in Java?

In order to develop a text editor in Java, the user is able to open several files with a object JTabbedPane. Then, I stores such files on HashMap<String,TabManager>. (The key of the HashMap), should to be the name of the file. After, I have on memory the files opened within of HashMap. Now, I need manage my tabs. For example, if the user is on tab selected by it, is evident that the user would like to change the font of the text, save file selected, copy it, and so on. For manage the tab selected by the user, I need of a class to get just the objects from tab selected, just. Such as, JTextPane and File. Basically, I should do:

    for(Map.Entry<String, TabManager> entry: HashMap.entry)
    {

        String key = entry.getKey();

        tabManager = entry.getValue();

        if(tab.getTabSelected().equals(key))
        {
                            // resquest objects from tab selected by the user
             this.container = tabManager.getJTextPane();
             this.file = tabManager.getFile();
        }

    }

I have on my hands the objects from tab selected by the user. Now, I going to handle it. The issue is:

How I handle this data ?

Upvotes: 1

Views: 228

Answers (1)

fabien
fabien

Reputation: 1549

I can't see what is the name of your map... But assuming you have something like:

Map<String, TabManager> map = new HashMap<>();

where the string is the name of your tab, is unique per tab, and that you can get that name with tab.getTabSelected(), then you can do:

TabManager selectedTab = map.get(tab.getTabSelected());

to get the selected tab.

About your second question: how to handle that big data... Since you don't want to read and copy in memory the entire file every time, you want:

  • start and end file pointers to know which chunk of the file you are currently displaying
  • cache for all tabs the page each of them displays
  • open the file when the tab is selected and the cache is out-of-date or not covering the info you need, close it when the tab is not selected anymore (and/or after some time). Other optimizations are possible...

Upvotes: 1

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