Mega Code Archive
Create a simple browser in Swing
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import java.awt.BorderLayout;
import java.awt.Cursor;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.net.URL;
import java.util.ArrayList;
import javax.swing.JButton;
import javax.swing.JEditorPane;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.event.HyperlinkEvent;
import javax.swing.event.HyperlinkListener;
import javax.swing.text.html.HTMLDocument;
import javax.swing.text.html.HTMLFrameHyperlinkEvent;
public class MiniBrowser extends JFrame implements HyperlinkListener {
private JButton backButton = new JButton("<"), forwardButton = new JButton(">");
private JTextField locationTextField = new JTextField(35);
private JEditorPane displayEditorPane = new JEditorPane();
private ArrayList pageList = new ArrayList();
public MiniBrowser() {
setSize(640, 480);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel buttonPanel = new JPanel();
backButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
actionBack();
}
});
backButton.setEnabled(false);
buttonPanel.add(backButton);
forwardButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
actionForward();
}
});
forwardButton.setEnabled(false);
buttonPanel.add(forwardButton);
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);
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);
}
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) {
}
}
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) {
}
}
private void actionGo() {
URL verifiedUrl = verifyUrl(locationTextField.getText());
if (verifiedUrl != null) {
showPage(verifiedUrl, true);
} else {
System.out.println("Invalid URL");
}
}
private URL verifyUrl(String url) {
if (!url.toLowerCase().startsWith("http://"))
return null;
URL verifiedUrl = null;
try {
verifiedUrl = new URL(url);
} catch (Exception e) {
return null;
}
return verifiedUrl;
}
private void showPage(URL pageUrl, boolean addToList) {
try {
URL currentUrl = displayEditorPane.getPage();
displayEditorPane.setPage(pageUrl);
URL newUrl = displayEditorPane.getPage();
if (addToList) {
int listSize = pageList.size();
if (listSize <= 0) {
return;
}
int pageIndex = pageList.indexOf(currentUrl.toString());
if (pageIndex >= listSize - 1) {
return;
}
for (int i = listSize - 1; i > pageIndex; i--) {
pageList.remove(i);
}
pageList.add(newUrl.toString());
}
locationTextField.setText(newUrl.toString());
updateButtons();
} catch (Exception e) {
System.out.println("Unable to load page");
}
}
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));
}
}
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);
}
}
}
public static void main(String[] args) {
MiniBrowser browser = new MiniBrowser();
browser.setVisible(true);
}
}
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