Desing a java Wb Browser..

Discussion in 'Java' started by markwilson, Sep 19, 2008.

  1. markwilson

    markwilson New Member

    Joined:
    Sep 2, 2008
    Messages:
    3
    Likes Received:
    0
    Trophy Points:
    0
    hi friends,
    can u help me in, Designing a new web browser
    i have some sample code to desing a new browser

    Code:
    import java.awt.*;
    import java.awt.event.*;
    import java.net.*;
    import java.util.*;
    import javax.swing.*;
    import javax.swing.event.*;
    import javax.swing.text.html.*;
    
    // The Mini Web Browser.
    public class MiniBrowser extends JFrame
    implements HyperlinkListener
    {
    // These are the buttons for iterating through the page list.
    private JButton backButton, forwardButton;
    
    // Page location text field.
    private JTextField locationTextField;
    
    // Editor pane for displaying pages.
    private JEditorPane displayEditorPane;
    
    // Browser's list of pages that have been visited.
    private ArrayList pageList = new ArrayList();
    
    // Constructor for Mini Web Browser.
    public MiniBrowser()
    {
    // Set application title.
    super("Mini Browser");
    
    // Set window size.
    setSize(640, 480);
    
    // Handle closing events.
    addWindowListener(new WindowAdapter() {
    public void windowClosing(WindowEvent e) {
    actionExit();
    }
    });
    
    // Set up file menu.
    JMenuBar menuBar = new JMenuBar();
    JMenu fileMenu = new JMenu("File");
    fileMenu.setMnemonic(KeyEvent.VK_F);
    JMenuItem fileExitMenuItem = new JMenuItem("Exit",
    KeyEvent.VK_X);
    fileExitMenuItem.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
    actionExit();
    }
    });
    fileMenu.add(fileExitMenuItem);
    menuBar.add(fileMenu);
    setJMenuBar(menuBar);
    
    // Set up button panel.
    JPanel buttonPanel = new JPanel();
    backButton = new JButton("< Back");
    backButton.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
    actionBack();
    }
    });
    backButton.setEnabled(false);
    buttonPanel.add(backButton);
    forwardButton = new JButton("Forward >");
    forwardButton.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
    actionForward();
    }
    });
    forwardButton.setEnabled(false);
    buttonPanel.add(forwardButton);
    locationTextField = new JTextField(35);
    locationTextField.addKeyListener(new KeyAdapter() {
    public void keyReleased(KeyEvent e) {
    if (e.getKeyCode() == KeyEvent.VK_ENTER) {
    actionGo();
    }
    }
    });
    buttonPanel.add(locationTextField);
    JButton goButton = new JButton("GO");
    goButton.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
    actionGo();
    }
    });
    buttonPanel.add(goButton);
    
    // Set up page display.
    displayEditorPane = new JEditorPane();
    displayEditorPane.setContentType("text/html");
    displayEditorPane.setEditable(false);
    displayEditorPane.addHyperlinkListener(this);
    
    getContentPane().setLayout(new BorderLayout());
    getContentPane().add(buttonPanel, BorderLayout.NORTH);
    getContentPane().add(new JScrollPane(displayEditorPane),
    BorderLayout.CENTER);
    }
    
    // Exit this program.
    private void actionExit() {
    System.exit(0);
    }
    
    // Go back to the page viewed before the current page.
    private void actionBack() {
    URL currentUrl = displayEditorPane.getPage();
    int pageIndex = pageList.indexOf(currentUrl.toString());
    try {
    showPage(
    new URL((String) pageList.get(pageIndex - 1)), false);
    }
    catch (Exception e) {}
    }
    
    // Go forward to the page viewed after the current page.
    private void actionForward() {
    URL currentUrl = displayEditorPane.getPage();
    int pageIndex = pageList.indexOf(currentUrl.toString());
    try {
    showPage(
    new URL((String) pageList.get(pageIndex + 1)), false);
    }
    catch (Exception e) {}
    }
    
    // Load and show the page specified in the location text field.
    private void actionGo() {
    URL verifiedUrl = verifyUrl(locationTextField.getText());
    if (verifiedUrl != null) {
    showPage(verifiedUrl, true);
    } else {
    showError("Invalid URL");
    }
    }
    
    // Show dialog box with error message.
    private void showError(String errorMessage) {
    JOptionPane.showMessageDialog(this, errorMessage,
    "Error", JOptionPane.ERROR_MESSAGE);
    }
    
    // Verify URL format.
    private URL verifyUrl(String url) {
    // Only allow HTTP URLs.
    if (!url.toLowerCase().startsWith("http://"))
    return null;
    
    // Verify format of URL.
    URL verifiedUrl = null;
    try {
    verifiedUrl = new URL(url);
    } catch (Exception e) {
    return null;
    }
    
    return verifiedUrl;
    }
    
    /* Show the specified page and add it to
    the page list if specified. */
    private void showPage(URL pageUrl, boolean addToList)
    {
    // Show hour glass cursor while crawling is under way.
    setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
    
    try {
    // Get URL of page currently being displayed.
    URL currentUrl = displayEditorPane.getPage();
    
    // Load and display specified page.
    displayEditorPane.setPage(pageUrl);
    
    // Get URL of new page being displayed.
    URL newUrl = displayEditorPane.getPage();
    
    // Add page to list if specified.
    if (addToList) {
    int listSize = pageList.size();
    if (listSize > 0) {
    int pageIndex =
    pageList.indexOf(currentUrl.toString());
    if (pageIndex < listSize - 1) {
    for (int i = listSize - 1; i > pageIndex; i--) {
    pageList.remove(i);
    }
    }
    }
    pageList.add(newUrl.toString());
    }
    
    // Update location text field with URL of current page.
    locationTextField.setText(newUrl.toString());
    
    // Update buttons based on the page being displayed.
    updateButtons();
    }
    catch (Exception e)
    {
    // Show error messsage.
    showError("Unable to load page");
    }
    finally
    {
    // Return to default cursor.
    setCursor(Cursor.getDefaultCursor());
    }
    }
    
    /* Update back and forward buttons based on
    the page being displayed. */
    private void updateButtons() {
    if (pageList.size() < 2) {
    backButton.setEnabled(false);
    forwardButton.setEnabled(false);
    } else {
    URL currentUrl = displayEditorPane.getPage();
    int pageIndex = pageList.indexOf(currentUrl.toString());
    backButton.setEnabled(pageIndex > 0);
    forwardButton.setEnabled(
    pageIndex < (pageList.size() - 1));
    }
    }
    
    // Handle hyperlink's being clicked.
    public void hyperlinkUpdate(HyperlinkEvent event) {
    HyperlinkEvent.EventType eventType = event.getEventType();
    if (eventType == HyperlinkEvent.EventType.ACTIVATED) {
    if (event instanceof HTMLFrameHyperlinkEvent) {
    HTMLFrameHyperlinkEvent linkEvent =
    (HTMLFrameHyperlinkEvent) event;
    HTMLDocument document =
    (HTMLDocument) displayEditorPane.getDocument();
    document.processHTMLFrameHyperlinkEvent(linkEvent);
    } else {
    showPage(event.getURL(), true);
    }
    }
    }
    
    // Run the Mini Browser.
    public static void main(String[] args) {
    MiniBrowser browser = new MiniBrowser();
    browser.show();
    }
    }
    
    
    
    but its not sufficient , it only show's URL bar and Go button
    i want some advance level
    like
    1. Next ,Prev ,Stop , Refresh Buttons
    2. Status Bar
    and some good Grapics look
    hope u will help me ,
    Thank you,
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice