Java Code Snippets

Provides framework templates including Java 2 Application, Java 2 Dialog and Java 2 Applet.

Version 2.0.0.1. Released: 2008-09-02.

References: Java 2 Standard Edition.

/* Standard Java 2 version 1.4+ Application Template */ // Uncomment and complete the line below to use pakaging // package company.appPackage; import java.awt.*; import java.awt.event.*; import javax.swing.*; public class JTemplate { // Global variables JFrame frame; JLabel label; public JTemplate(String[] args) { JFrame.setDefaultLookAndFeelDecorated(true); JDialog.setDefaultLookAndFeelDecorated(true); frame = new JFrame("Title"); label = new JLabel("Template"); // Create panel and add components final JPanel pane = new JPanel(); pane.setBorder(BorderFactory.createEmptyBorder(10,10,10,10)); pane.setLayout(new BorderLayout()); pane.add(label, BorderLayout.CENTER); frame.getContentPane().add(pane, BorderLayout.CENTER); // Exit app frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); /* Exit app for more advanced exit functionality frame.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } // end (method)WindowClosing } // end (object)WindowAdapter ); */ // Sets size and centers the frame frame.setSize(400, 300); Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize(); int screenW = screenSize.width; int screenH = screenSize.height; Dimension frameSize = frame.getSize(); int x = (screenW - frameSize.width) / 2; int y = (screenH - frameSize.height) / 2; frame.setLocation(x, y); frame.setVisible(true); } // end (constructor)JTemplate // Program entry point /** Main App Threading for Java 1.4 and higher. * * @param sargs Command Line Arguments as a String Array passed from main(). */ public static void loadApp(String[] sargs) { JTemplate app = new JTemplate(sargs); } // end (method)buildApp /** The main method implementing the application. * * @param args Command Line Arguments as a String Array. */ public static void main(final String[] args) { javax.swing.SwingUtilities.invokeLater(new Runnable() { public void run() { loadApp(args); } // end (method)run }); } // end (method)main } // end (class)JTemplate
/* Standard Java 2 Application Template */ // Uncomment and complete the line below to use pakaging // package company.appPackage; import java.awt.*; import java.awt.event.*; import javax.swing.*; public class JTemplate { // Global variables JFrame frame; JLabel label; public JTemplate() { frame = new JFrame("Title"); label = new JLabel("Template"); // Create panel and add components final JPanel pane = new JPanel(); pane.setBorder(BorderFactory.createEmptyBorder(10,10,10,10)); pane.setLayout(new BorderLayout()); pane.add(label, BorderLayout.CENTER); frame.getContentPane().add(pane, BorderLayout.CENTER); // Exit app frame.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } // end (method)WindowClosing } // end (object)WindowAdapter ); /* // Exit app (Java 1.3 and higher) frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); */ // Sets size and centers the frame frame.setSize(400, 300); Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize(); int screenW = screenSize.width; int screenH = screenSize.height; Dimension frameSize = frame.getSize(); int x = (screenW - frameSize.width) / 2; int y = (screenH - frameSize.height) / 2; frame.setLocation(x, y); frame.setVisible(true); } // end (constructor)JTemplate // Program entry point /** The main method implementing the application. * * @param args Command Line Arguments as a String Array. */ public static void main(String[] args) { JTemplate app = new JTemplate(); } // end (method)main } // end (class)JTemplate
/* Standard Java 2 Dialog for application */ import java.io.*; import java.io.File; import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.event.*; class JDialogTemplate extends JDialog { public JDialogTemplate(JFrame aFrame) { super(aFrame); // This JDialog method below is for Java 1.4 and higher if you don't have this in the main class file: // JDialog.setDefaultLookAndFeelDecorated(true); setTitle("Dialog"); JLabel l = new JLabel("Hello"); JPanel pane = new JPanel(); pane.setBorder(BorderFactory.createEmptyBorder(10,10,10,10)); pane.setLayout(new BorderLayout()); pane.add(l); getContentPane().add(pane, BorderLayout.CENTER); setSize(400, 300); Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize(); int screenW = screenSize.width; int screenH = screenSize.height; Dimension frameSize = getSize(); int x = (screenW - frameSize.width) / 2; int y = (screenH - frameSize.height) / 2; setLocation(x, y); setDefaultCloseOperation(JDialog.HIDE_ON_CLOSE); setResizable(false); setVisible(true); } // end (constructor)JDialogTemplate } // end (class)JDialogTemplate
// Standard Java 2 Applet Template import java.awt.*; import java.awt.event.*; import javax.swing.*; public class JAppletTemplate extends JApplet { // Global variables JLabel l; JMenuBar mb; JMenu m; JMenuItem mi; // Initialise the applet public void init() { // Get a parameter from <param name="theText" value="..."> like this below: // String text = getParameter("theText"); l = new JLabel("You should use object element not applet or embed"); // Setup a menu system mb = new JMenuBar(); m = new JMenu("Menu"); mb.add(m); mi = new JMenuItem("Item"); mi.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { JOptionPane.showMessageDialog(getContentPane(), "This is a JApplet You should use object element not applet or embed"); } // end (method)actionPerformed }); m.add(mi); setJMenuBar(mb); getContentPane().add(l); } // end (method)init // Any actions to begin when starting the applet or returning to the webpage // public void start() { // } // end (method)start // Any old applet painting? // public void paint(Graphics g) { // } // end (method)paint // Stop any actions, begun in (method)start, when leaving the webpage // public void stop() { // } // end (method)stop // Your own clean up stuff when the applet is unloaded (such as when you close the web browser). // public void destroy() { // } // end (method)destroy } // end (class)JAppletTemplate
if (a > b) { // Do this c = "and this"; } // end if a is greater than b
if (a > b) { // Do this c = "and this"; } else { // Do other } // end if a is greater than b
if (a > b) { // Do this c = "and this"; } else if (a < b) { // Do that c = "and this"; } else { // The same } // end if a is greater than b
while (c > 25) { // Do all that } // end while
// Unfortunately Java's Switch is limited to byte, short, int and char types switch (var) { case 1: a = "Do this"; break; case 2: a = "Do that"; break; default: a = "Default stuff"; } // end switch var
for (i=0; i<25; i++) { // Iterate through the range } // end for i[0-25]
try { // try something } catch (ErrorType errorvar) { // handle error } // end try-catch
try { // try something } catch (ErrorType errorvar) { // handle error } finally { // finalise } // end try-catch-finally
catch (ErrorType errorvar) { // handle error }

Web-based Code Snippets are copywritten 2008 to Legend Scrolls and Peter Davison.
Web-based Code Snippets are licensed under the Creative Commons Attribution 3.0 Unported.