browse html files in java swing [duplicate]

霸气de小男生 提交于 2020-01-14 14:39:08

问题


Possible Duplicate:
Swing JDialog/JTextPane and HTML links

I want to browse HTML files in swing and I have done that, the content of html file is being displayed with the help of JEditorPane but links of html file are not opening another HTML file into the same pane. Is it possible in swing? I want the html file should treat like pure HTML files means link should work there in JAVA editor pane also currently i am using the following code.

try
{
  FileInputStream fstream = new FileInputStream("src\\html\\test.html");
  DataInputStream in = new DataInputStream(fstream);
  BufferedReader br = new BufferedReader(new InputStreamReader(in));
  String strLine;
  String text="";
  while ((strLine = br.readLine()) != null)   {
    text=text+strLine+"\n";
  }
  JEditorPane htmlPane = new JEditorPane("text/html",text);
  cp.add(htmlPane);
  htmlPane.setBounds(750,50,600,600);
 }catch(Exception ex){
  JOptionPane.showMessageDialog(null,"exception is"+ex)   ;
 }

回答1:


This example shows how to create a simple browser in Swing.

The course code of the simple browser is written below:

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();
    }
}

Ref: http://www.java-tips.org/java-se-tips/javax.swing/how-to-create-a-simple-browser-in-swing-3.html




回答2:


From JEditorPane Javadocs:

Some kinds of content may provide hyperlink support by generating hyperlink events. The HTML EditorKit will generate hyperlink events if the JEditorPane is not editable (JEditorPane.setEditable(false); has been called). If HTML frames are embedded in the document, the typical response would be to change a portion of the current document. The following code fragment is a possible hyperlink listener implementation, that treats HTML frame events specially, and simply displays any other activated hyperlinks.

class Hyperactive implements HyperlinkListener {

     public void hyperlinkUpdate(HyperlinkEvent e) {
         if (e.getEventType() == HyperlinkEvent.EventType.ACTIVATED) {
             JEditorPane pane = (JEditorPane) e.getSource();
             if (e instanceof HTMLFrameHyperlinkEvent) {
                 HTMLFrameHyperlinkEvent  evt = (HTMLFrameHyperlinkEvent)e;
                 HTMLDocument doc = (HTMLDocument)pane.getDocument();
                 doc.processHTMLFrameHyperlinkEvent(evt);
             } else {
                 try {
                     pane.setPage(e.getURL());
                 } catch (Throwable t) {
                     t.printStackTrace();
                 }
             }
         }
     }
 }

So:

htmlPane.setEditable(false); 
htmlPane.addHyperlinkListener(new Hyperactive());



回答3:


From the documentation for the JEditorPane.

Some kinds of content may provide hyperlink support by generating hyperlink events. The HTML EditorKit will generate hyperlink events if the JEditorPane is not editable (JEditorPane.setEditable(false); has been called). ...

Continue reading those docs. for the tip mentioned in the other answer.


BTW

  FileInputStream fstream = new FileInputStream("src\\html\\test.html");
  DataInputStream in = new DataInputStream(fstream);
  BufferedReader br = new BufferedReader(new InputStreamReader(in));
  String strLine;
  String text="";
  while ((strLine = br.readLine()) != null)   {
    text=text+strLine+"\n";
  }
  JEditorPane htmlPane = new JEditorPane("text/html",text);

Could be replaced with..

  File file = new File("src\\html\\test.html");
  JEditorPane htmlPane = new JEditorPane(file.toURI().toURL());



回答4:


you can use dj project to embed a native browser, this way you can render html+js+css and follow links or even render flash. sourceforge.net/projects/djproject/



来源:https://stackoverflow.com/questions/12540659/browse-html-files-in-java-swing

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