Demo the System Tray in java

ReadMe

# Get these files and copy it to a directory
# Get a .png file and rename it to coffee.png and also put the the same directory as the source file
# compile and run it with command:

$ java -cp . WindowNotifier

TestFrame.java

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 *
 * @author Steven Ou
 */
public class TestFrame extends javax.swing.JFrame {

    /**
     * Creates new form TestFrame
     */
    public TestFrame() {
        initComponents();
    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jLabel1 = new javax.swing.JLabel();
        jScrollPane1 = new javax.swing.JScrollPane();
        jTextArea1 = new javax.swing.JTextArea();
        jButton1 = new javax.swing.JButton();
        jButton2 = new javax.swing.JButton();

        jLabel1.setText("Please enter your text");

        jTextArea1.setColumns(20);
        jTextArea1.setRows(5);
        jScrollPane1.setViewportView(jTextArea1);

        jButton1.setText("Save");
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton1ActionPerformed(evt);
            }
        });

        jButton2.setText("Exit");
        jButton2.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton2ActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(28, 28, 28)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jLabel1)
                    .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 351, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addContainerGap(21, Short.MAX_VALUE))
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addComponent(jButton1)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addComponent(jButton2)
                .addGap(24, 24, 24))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(27, 27, 27)
                .addComponent(jLabel1)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 202, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jButton1)
                    .addComponent(jButton2))
                .addContainerGap(17, Short.MAX_VALUE))
        );

        pack();
    }// </editor-fold>                        

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        // TODO add your handling code here:
    }                                        

    private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        this.setVisible( false );
    }                                        

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(TestFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(TestFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(TestFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(TestFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new TestFrame().setVisible(true);
            }
        });
    }
    // Variables declaration - do not modify                     
    private javax.swing.JButton jButton1;
    private javax.swing.JButton jButton2;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JTextArea jTextArea1;
    // End of variables declaration                   
}

WindowNotifier.java

import java.awt.AWTException;
import java.awt.Dimension;
import java.awt.Image;
import java.awt.MenuItem;
import java.awt.PopupMenu;
import java.awt.SystemTray;
import java.awt.Toolkit;
import java.awt.TrayIcon;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.net.URL;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Timer;
import java.util.TimerTask;
import javax.swing.JFrame;


/**
 *
 * @author Steven Ou
 */
public class WindowNotifier {
    private static final String IMAGE_NAME = "coffee.png";
    private final SystemTray systemTray = SystemTray.getSystemTray();
    private final TrayIcon icon;
    private final Timer timer = new Timer();
    private final JFrame frame = new TestFrame();
    
    
    public WindowNotifier() throws AWTException {
        Toolkit tk = Toolkit.getDefaultToolkit();
        
        PopupMenu popMenu = new PopupMenu();
        MenuItem item = new MenuItem("Exit");
        item.addActionListener( new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                System.exit( 0 );
            }
        });
                
         popMenu.add( item );
         
         item = new MenuItem("Show Context");
         
         item.addActionListener( new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                frame.setVisible( true );
            }
        });
         
         popMenu.add( item );
         
        this.icon = new TrayIcon( getImage( IMAGE_NAME ), "test", popMenu );
        this.icon.setImageAutoSize(true);
        this.systemTray.add( this.icon );
        
        this.timer.schedule(new TimerTask() {

            @Override
            public void run() {
                WindowNotifier.this.icon.displayMessage( "New Message", "Current time is:" + new SimpleDateFormat( "yyyy-MM-dd HH:mm:ss.SSS").format( Calendar.getInstance().getTime() ), TrayIcon.MessageType.INFO );
            }
        }, 5*1000, 10*1000 );
        centerFrame();
    }
         
    private Image getImage( String name ) {
        URL url = getClass().getResource(name);
        return Toolkit.getDefaultToolkit().getImage(url);
    }
    
    private void centerFrame() {
        Dimension d = Toolkit.getDefaultToolkit().getScreenSize();
        int x = (int)( ( d.getWidth() - frame.getWidth() ) / 2);
        int y = (int)( ( d.getHeight() - frame.getHeight() ) / 2);
        frame.setLocation( x, y );
    }
    
    public static void main( String...args ) throws AWTException {
        new WindowNotifier();
    }
    
    
}