Search string instantly by JTextField and JList

Question

I'm making a dictionary application, which has a search function. When we type something to the textfield, we want receive a list result in the JList instantly, but I can't make it has been done instantly, always has latency, maybe 50ms.

Meanwhile I'm using another application, which can do it with 0ms latency. You can see it there: video

I'm using prefix tree. Here is my code:

Dictionary trie to search words.

// I have another arraylist **dictionary** contains all words
// you can see attribute **count** in DictionaryTrie, and **index** in Node
// You can see that: I use Trie to find index, and I use index to receive a list through dictionary
public class DictionaryTrie {
    private final Node root;
    private static int count;
    private static ArrayList<Word> dictionary;
    public DictionaryTrie() {
        count = 0;
        root = new Node(count);
        dictionary = Dictionary.getInstance().getDictionary();
    }
    
    public void insert(Word newWord) {
        String word = newWord.getWordTarget();
        Node currentNode = root;
        for (int i = 0; i < word.length(); i++) {
            char c = word.charAt(i);
            Node node = currentNode.children.get(c);
            if (node == null) {
                node = new Node(count);
                currentNode.children.put(c, node);
            }
            currentNode = node;
        }
        count++;
    }
    
    public ArrayList<Word> search(String word) {
        ArrayList<Word> list = new ArrayList<Word>();
        Node currentNode = root;
        for (int i = 0; i < word.length(); i++) {
            char c = word.charAt(i);
            Node node = currentNode.children.get(c);
            if (node == null) {
                return null;
            }
            currentNode = node;
        }
        int start = currentNode.index;
        for (int i = start; i < Math.min(dictionary.size(), start + 15); i++) {
            list.add(dictionary.get(i));
        }
        return list;
    }
    
    
    private class Node {
        public Map<Character, Node> children;
        public int index; 
        
        public Node(int idx) {
            children = new HashMap<Character, Node>();
            index = idx;
        }
    }
}

Dictionary Management:

public class DictionaryManagement {
    
    private static DictionaryManagement instance;
    private static Dictionary dict;
    private static ArrayList<Word> listWord;
    private static DictionaryTrie dictionaryTrie;
    ConnectJDBC connectJDBC;
    Connection conn;

    private DictionaryManagement() {
        dict = Dictionary.getInstance();
        listWord = dict.getDictionary();
        dictionaryTrie = new DictionaryTrie();
    }

    public static DictionaryManagement getInstance() {
        if (instance == null) {
            instance = new DictionaryManagement();
        }
        return instance;
    }

    
    public ArrayList<Word> searchWord(String word) {
        return dictionaryTrie.search(word);
    }
}

Search controller

public class SearchController{
    private ListWord listWord;
    private JTextField searchField;
    private DictionaryManagement dictionaryManagement;
    
    public SearchController(ListWord list, JTextField field) {
        dictionaryManagement = DictionaryManagement.getInstance();
        this.listWord = list;
        this.searchField = field;
        this.searchField.addKeyListener(new SearchFieldListener());
    }
    
    private void search(String string) {
        ArrayList<Word> list = dictionaryManagement.searchWord(string);
        listWord.removeItem();
        if (list != null) {
            listWord.addItem(list);
        }
        listWord.setSelectedIndex(-1);
    }
    
    private class SearchFieldListener implements KeyListener{

        @Override
        public void keyTyped(KeyEvent e) {
            
        }

        @Override
        public void keyPressed(KeyEvent e) {
            
        }

        @Override
        public void keyReleased(KeyEvent e) {
            String text = searchField.getText();
            search(text);
        }
        
    }
}

Main

searchController = new SearchController(listWord, searchField);

I think I have no problem with my algorithm.