Question

I want to create an auto-complete program in java which should provide a list of suggestions instantly when the user types a character/String inside a JTextfield. The problem is that I am confused on how to do it.

Could somebody provide an idea or a sample on the said problem?

Answer 1

1) you have to sort your array before use for better performance…

2) as I mentioned you have to take these two clasess

3) don’t forget set initial value for better and nicest work with these Components

simple output

from code

import java.awt.*;
import java.util.ArrayList;
import javax.swing.*;

public class AutoCompleteTextField {

    private JFrame frame;
    private ArrayList<String> listSomeString = new ArrayList<String>();
    private Java2sAutoTextField someTextField = new Java2sAutoTextField(listSomeString);
    private ArrayList<String> listSomeAnotherString = new ArrayList<String>();
    private Java2sAutoComboBox someComboBox = new Java2sAutoComboBox(listSomeAnotherString);

    public AutoCompleteTextField() {
        listSomeString.add("-");
        listSomeString.add("Snowboarding");
        listSomeString.add("Rowing");
        listSomeString.add("Knitting");
        listSomeString.add("Speed reading");
        listSomeString.add("Pool");
        listSomeString.add("None of the above");
//
        listSomeAnotherString.add("-");
        listSomeAnotherString.add("XxxZxx Snowboarding");
        listSomeAnotherString.add("AaaBbb Rowing");
        listSomeAnotherString.add("CccDdd Knitting");
        listSomeAnotherString.add("Eee Fff Speed reading");
        listSomeAnotherString.add("Eee Fff Pool");
        listSomeAnotherString.add("Eee Fff None of the above");
//
        someTextField.setFont(new Font("Serif", Font.BOLD, 16));
        someTextField.setForeground(Color.black);
        someTextField.setBackground(Color.orange);
        someTextField.setName("someTextField");
        someTextField.setDataList(listSomeString);
//
        someComboBox.setPrototypeDisplayValue("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
        someComboBox.setFont(new Font("Serif", Font.BOLD, 16));
        someComboBox.setForeground(Color.black);
        someComboBox.setBackground(Color.YELLOW);
        someComboBox.getEditor().selectAll();
        someComboBox.getEditor().getEditorComponent().setBackground(Color.YELLOW);
        ((JTextField) someComboBox.getEditor().getEditorComponent()).setDisabledTextColor(Color.black);
        someComboBox.setName("someComboBox");
        someComboBox.setDataList(listSomeAnotherString);
//
        frame = new JFrame();
        frame.setLayout(new GridLayout(0, 1, 10, 10));
        frame.add(someTextField);
        frame.add(someComboBox);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLocation(100, 100);
        frame.pack();
        frame.setVisible(true);
//
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                someTextField.setText("-");
                someComboBox.getEditor().setItem(0);
                someComboBox.getEditor().selectAll();
                someTextField.grabFocus();
                someTextField.requestFocus();
                someTextField.setText(someTextField.getText());
                someTextField.selectAll();
            }
        });

    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                AutoCompleteTextField aCTF = new AutoCompleteTextField();
            }
        });
    }
}