Dynamically Changing List

Question

I am a beginner to Java.. Knows part of JDBC, AWT & Swings.. My problem is that, I am having an MS Access DB and a table contains a list some names..
I want to display all those names inside an AWT List (or something like that). When user starts entering the name into a TextField, this LIST should be updated dynamically sothat the list contains only the names which start with the letter typped in by the user.
For eg., initially, the list should contain all the names. If the user enters the letter "A", then the list should show only names that starts with "A". When he types "An", then the list should be updated to show names start with "An".
Can anyone help me in solving this problem?

Answer 1

This should solve your problem. Put the below code in its own file then make an FilteredJList object. You may also want to try running the main method so you can see what this class does.
The refilter() method in the FilterModel class is what sorts the data depending on what is entered into the text box. I set it to filter the objects in the list by ignoring the case, you can simply use .equals( instead of .equalsIgnoreCase( if you want it to take the case of the text into account.
import javax.swing.*;
import java.util.ArrayList;
import javax.swing.event.DocumentListener;
import javax.swing.event.DocumentEvent;
import java.awt.BorderLayout;
public class FilteredJList
    extends JList {
  private FilterField filterField;
  private int DEFAULT_FIELD_WIDTH = 20;
  public FilteredJList() {
    super();
    setModel(new FilterModel());
    filterField = new FilterField(DEFAULT_FIELD_WIDTH);
  public void setModel(ListModel m) {
    if (! (m instanceof FilterModel)) {
      throw new IllegalArgumentException();
    super.setModel(m);
  public void addItem(Object o) {
    ( (FilterModel) getModel()).addElement(o);
  public JTextField getFilterField() {
    return filterField;
  class FilterModel
      extends AbstractListModel {
    ArrayList items;
    ArrayList filterItems;
    public FilterModel() {
      super();
      items = new ArrayList();
      filterItems = new ArrayList();
    public Object getElementAt(int index) {
      if (index < filterItems.size()) {
        return filterItems.get(index);
      else {
        return null;
    public int getSize() {
      return filterItems.size();
    public void addElement(Object o) {
      items.add(o);
      refilter();
    private void refilter() {
      filterItems.clear();
      // Loop through every item in the list
      for (int i = 0; i < items.size(); i++) {
        // term is the item typed into the text field
        String term = getFilterField().getText();
        // the test string is the current item in the list
        String testString = items.get(i).toString();
        if (term.length() <= testString.length()) {
          // get the substring of the current item in the list
          // equal in length to the length of the text typed in
          testString = testString.substring(0, term.length());
          // test to see if the strings are equal, this test ignores case differences
          // to make it return false if the case matters, choose .equals() instead
          if (testString.equalsIgnoreCase(term)) {
            filterItems.add(items.get(i));
            fireContentsChanged(this, 0, getSize());
  } // End FilterModel
  class FilterField
      extends JTextField implements DocumentListener {
    public FilterField(int width) {
      super(width);
      getDocument().addDocumentListener(this);
    public void changedUpdate(DocumentEvent e) {
      ( (FilterModel) getModel()).refilter();
    public void insertUpdate(DocumentEvent e) {
      ( (FilterModel) getModel()).refilter();
    public void removeUpdate(DocumentEvent e) {
      ( (FilterModel) getModel()).refilter();
  } // End FilterField
  public static void main(String[] args) {
    String[] listItems = {
        "Chris", "Joshua", "Daniel", "Michael", "Don", "Kimi", "Kelly",
        "Keagan"};
    JFrame frame = new JFrame("FilteredJList");
    frame.getContentPane().setLayout(new BorderLayout());
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    // Populate the list
    FilteredJList list = new FilteredJList();
    for (int i = 0; i < listItems.length; i++) {
      list.addItem(listItems);
// add to GUI
JScrollPane scrollPane = new JScrollPane(list,
ScrollPaneConstants.
VERTICAL_SCROLLBAR_ALWAYS,
ScrollPaneConstants.
HORIZONTAL_SCROLLBAR_NEVER);
frame.getContentPane().add(scrollPane, BorderLayout.CENTER);
frame.getContentPane().add(list.getFilterField(), BorderLayout.NORTH);
frame.pack();
frame.setVisible(true);
} // End FilteredJList
Hope it helps.