Code Snippets ⇒ Word counter with BoxLayout

This Java code creates a GUI with a BoxLayout.
If you click on the button, the words in the text area are counted.

⇐ Go back

    import java.awt.Dimension;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
     
    import javax.swing.Box;
    import javax.swing.BoxLayout;
    import javax.swing.JButton;
    import javax.swing.JFrame;
    import javax.swing.JLabel;
    import javax.swing.JOptionPane;
    import javax.swing.JScrollPane;
    import javax.swing.JTextArea;
     
    /**
     * Word counter with BoxLayout.
     * This class represents a frame.
     * 
     * @version 1.0 07 May 2011
     * @author Michel Neeser
     *
     */
    public class WordCounter extends JFrame implements ActionListener {
        // Because we extend JFrame, we have access to all methods defined there.
        // With that, we're able to define the behaviour of our frame.
        // In addition, we implement the ActionListener interface.
        // So we're able to use this class not just to represent our frame,
        // but also to operate as a listener for the button on it.
        
        private static final long serialVersionUID = 1L; 
        private JTextArea textArea;
        private JButton button;
         
        /**
         * This is the no-arg constructor.
         * It takes no arguments (surprise!).
         * Calls initGUI().
         */
        private WordCounter() {
            // Build GUI in a seperate method.
            // This is good practice.
            initGUI();
        }
         
        /**
         * Builds the GUI.
         * Called by the constructor.
         */
        private void initGUI() {
            // Attention! Here begins the fun ...
             
            // set frame size (setSize is inherited from JFrame)
            setSize(500, 400);
            // show frame in center screen (setLocationRelativeTo is inherited)
            setLocationRelativeTo(null);
            // set title of the frame (setTitle is inherited)
            setTitle("This word counter rocks!");
            // set layout, we're going to use a vertical box layout
            setLayout(new BoxLayout(getContentPane(), BoxLayout.Y_AXIS));
             
            // add label within a box
            Box labelBox = Box.createHorizontalBox();
            labelBox.add(Box.createRigidArea(new Dimension(0, 50)));
            labelBox.add(new JLabel("Hi there! This is a word counter with box layout."));
            add(labelBox); // add box to layout
             
            // add text area within a box
            Box areaBox = Box.createHorizontalBox();
            areaBox.add(Box.createRigidArea(new Dimension(50, 0)));
            textArea = new JTextArea();
            areaBox.add(new JScrollPane(textArea));
            areaBox.add(Box.createRigidArea(new Dimension(50, 0)));
            add(areaBox); // add box to layout
             
            // add button within a box
            Box buttonBox = Box.createHorizontalBox();
            buttonBox.add(Box.createRigidArea(new Dimension(0, 50)));
            button = new JButton("Count words!");
            buttonBox.add(button);
            add(buttonBox); // add box to layout
             
            // add action listener to the button
            button.addActionListener(this);
        }
         
        /**
         * Called when the user pushes on the button (inherited from ActionListener interface).
         */
        public void actionPerformed(ActionEvent evt) {
            String text = textArea.getText();
            int wordNumber;
            if (text.equals("")) {
                wordNumber = 0;
            }
            else {
                String[] countWords = textArea.getText().split(" "); // split words
                wordNumber = countWords.length; // count words
            }
            JOptionPane.showMessageDialog(null, "Number of words: " + wordNumber, "Message", JOptionPane.INFORMATION_MESSAGE);
        }
        
        /**
         * Instantiates a new instance of WordCounter.
         * @param args the command line args -> not used in code
         */ 
        public static void main(String[] args) {
            // create instance of WordCounter and make it visible
        	WordCounter wc = new WordCounter();
        	wc.setVisible(true);
        }
         
    }