WebView

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 Simple 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();
  }
}