How to add hyperlink in JLabel?
What is the best way to add a hyperlink in a JLabel? I can get the view using html tags, but how to open the browser when the user clicks on it?
You can do this using a JLabel, but an alternative would be to style a JButton. That way, you don't have to worry about accessibility and can just fire events using an ActionListener.
public static void main(String[] args) throws URISyntaxException {
final URI uri = new URI("http://java.sun.com");
class OpenUrlAction implements ActionListener {
@Override public void actionPerformed(ActionEvent e) {
open(uri);
}
}
JFrame frame = new JFrame("Links");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(100, 400);
Container container = frame.getContentPane();
container.setLayout(new GridBagLayout());
JButton button = new JButton();
button.setText("<HTML>Click the <FONT color=\"#000099\"><U>link</U></FONT>"
+ " to go to the Java website.</HTML>");
button.setHorizontalAlignment(SwingConstants.LEFT);
button.setBorderPainted(false);
button.setOpaque(false);
button.setBackground(Color.WHITE);
button.setToolTipText(uri.toString());
button.addActionListener(new OpenUrlAction());
container.add(button);
frame.setVisible(true);
}
private static void open(URI uri) {
if (Desktop.isDesktopSupported()) {
try {
Desktop.getDesktop().browse(uri);
} catch (IOException e) { /* TODO: error handling */ }
} else { /* TODO: error handling */ }
}
I'd like to offer yet another solution. It's similar to the already proposed ones as it uses HTML-code in a JLabel, and registers a MouseListener on it, but it also displays a HandCursor when you move the mouse over the link, so the look&feel is just like what most users would expect. If browsing is not supported by the platform, no blue, underlined HTML-link is created that could mislead the user. Instead, the link is just presented as plain text. This could be combined with the SwingLink class proposed by @dimo414.
public class JLabelLink extends JFrame {
private static final String LABEL_TEXT = "For further information visit:";
private static final String A_VALID_LINK = "http://stackoverflow.com";
private static final String A_HREF = "<a href=\"";
private static final String HREF_CLOSED = "\">";
private static final String HREF_END = "</a>";
private static final String HTML = "<html>";
private static final String HTML_END = "</html>";
public JLabelLink() {
setTitle("HTML link via a JLabel");
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
Container contentPane = getContentPane();
contentPane.setLayout(new FlowLayout(FlowLayout.LEFT));
JLabel label = new JLabel(LABEL_TEXT);
contentPane.add(label);
label = new JLabel(A_VALID_LINK);
contentPane.add(label);
if (isBrowsingSupported()) {
makeLinkable(label, new LinkMouseListener());
}
pack();
}
private static void makeLinkable(JLabel c, MouseListener ml) {
assert ml != null;
c.setText(htmlIfy(linkIfy(c.getText())));
c.setCursor(new java.awt.Cursor(java.awt.Cursor.HAND_CURSOR));
c.addMouseListener(ml);
}
private static boolean isBrowsingSupported() {
if (!Desktop.isDesktopSupported()) {
return false;
}
boolean result = false;
Desktop desktop = java.awt.Desktop.getDesktop();
if (desktop.isSupported(Desktop.Action.BROWSE)) {
result = true;
}
return result;
}
private static class LinkMouseListener extends MouseAdapter {
@Override
public void mouseClicked(java.awt.event.MouseEvent evt) {
JLabel l = (JLabel) evt.getSource();
try {
URI uri = new java.net.URI(JLabelLink.getPlainLink(l.getText()));
(new LinkRunner(uri)).execute();
} catch (URISyntaxException use) {
throw new AssertionError(use + ": " + l.getText()); //NOI18N
}
}
}
private static class LinkRunner extends SwingWorker<Void, Void> {
private final URI uri;
private LinkRunner(URI u) {
if (u == null) {
throw new NullPointerException();
}
uri = u;
}
@Override
protected Void doInBackground() throws Exception {
Desktop desktop = java.awt.Desktop.getDesktop();
desktop.browse(uri);
return null;
}
@Override
protected void done() {
try {
get();
} catch (ExecutionException ee) {
handleException(uri, ee);
} catch (InterruptedException ie) {
handleException(uri, ie);
}
}
private static void handleException(URI u, Exception e) {
JOptionPane.showMessageDialog(null, "Sorry, a problem occurred while trying to open this link in your system's standard browser.", "A problem occured", JOptionPane.ERROR_MESSAGE);
}
}
private static String getPlainLink(String s) {
return s.substring(s.indexOf(A_HREF) + A_HREF.length(), s.indexOf(HREF_CLOSED));
}
//WARNING
//This method requires that s is a plain string that requires
//no further escaping
private static String linkIfy(String s) {
return A_HREF.concat(s).concat(HREF_CLOSED).concat(s).concat(HREF_END);
}
//WARNING
//This method requires that s is a plain string that requires
//no further escaping
private static String htmlIfy(String s) {
return HTML.concat(s).concat(HTML_END);
}
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new JLabelLink().setVisible(true);
}
});
}
}
I wrote an article on how to set a hyperlink or a mailto on a jLabel.
So just try it :
I think that's exactly what you're searching for.
Here's the complete code example :
/**
* Example of a jLabel Hyperlink and a jLabel Mailto
*/
import java.awt.Cursor;
import java.awt.Desktop;
import java.awt.EventQueue;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
/**
*
* @author ibrabelware
*/
public class JLabelLink extends JFrame {
private JPanel pan;
private JLabel contact;
private JLabel website;
/**
* Creates new form JLabelLink
*/
public JLabelLink() {
this.setTitle("jLabelLinkExample");
this.setSize(300, 100);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setLocationRelativeTo(null);
pan = new JPanel();
contact = new JLabel();
website = new JLabel();
contact.setText("<html> contact : <a href=\"\">[email protected]</a></html>");
contact.setCursor(new Cursor(Cursor.HAND_CURSOR));
website.setText("<html> Website : <a href=\"\">http://www.google.com/</a></html>");
website.setCursor(new Cursor(Cursor.HAND_CURSOR));
pan.add(contact);
pan.add(website);
this.setContentPane(pan);
this.setVisible(true);
sendMail(contact);
goWebsite(website);
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
/*
* Create and display the form
*/
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
new JLabelLink().setVisible(true);
}
});
}
private void goWebsite(JLabel website) {
website.addMouseListener(new MouseAdapter() {
@Override
public void mouseClicked(MouseEvent e) {
try {
Desktop.getDesktop().browse(new URI("http://www.google.com/webhp?nomo=1&hl=fr"));
} catch (URISyntaxException | IOException ex) {
//It looks like there's a problem
}
}
});
}
private void sendMail(JLabel contact) {
contact.addMouseListener(new MouseAdapter() {
@Override
public void mouseClicked(MouseEvent e) {
try {
Desktop.getDesktop().mail(new URI("mailto:[email protected]?subject=TEST"));
} catch (URISyntaxException | IOException ex) {
//It looks like there's a problem
}
}
});
}
}
Update I've tidied up the SwingLink class further and added more features; an up-to-date copy of it can be found here: https://bitbucket.org/dimo414/jgrep/src/tip/src/grep/SwingLink.java
@McDowell's answer is great, but there's several things that could be improved upon. Notably text other than the hyperlink is clickable and it still looks like a button even though some of the styling has been changed/hidden. While accessibility is important, a coherent UI is as well.
So I put together a class extending JLabel based on McDowell's code. It's self-contained, handles errors properly, and feels more like a link:
public class SwingLink extends JLabel {
private static final long serialVersionUID = 8273875024682878518L;
private String text;
private URI uri;
public SwingLink(String text, URI uri){
super();
setup(text,uri);
}
public SwingLink(String text, String uri){
super();
setup(text,URI.create(uri));
}
public void setup(String t, URI u){
text = t;
uri = u;
setText(text);
setToolTipText(uri.toString());
addMouseListener(new MouseAdapter() {
public void mouseClicked(MouseEvent e) {
open(uri);
}
public void mouseEntered(MouseEvent e) {
setText(text,false);
}
public void mouseExited(MouseEvent e) {
setText(text,true);
}
});
}
@Override
public void setText(String text){
setText(text,true);
}
public void setText(String text, boolean ul){
String link = ul ? "<u>"+text+"</u>" : text;
super.setText("<html><span style=\"color: #000099;\">"+
link+"</span></html>");
this.text = text;
}
public String getRawText(){
return text;
}
private static void open(URI uri) {
if (Desktop.isDesktopSupported()) {
Desktop desktop = Desktop.getDesktop();
try {
desktop.browse(uri);
} catch (IOException e) {
JOptionPane.showMessageDialog(null,
"Failed to launch the link, your computer is likely misconfigured.",
"Cannot Launch Link",JOptionPane.WARNING_MESSAGE);
}
} else {
JOptionPane.showMessageDialog(null,
"Java is not able to launch links on your computer.",
"Cannot Launch Link", JOptionPane.WARNING_MESSAGE);
}
}
}
You could also, for instance, change the link color to purple after being clicked, if that seemed useful. It's all self contained, you simply call:
SwingLink link = new SwingLink("Java", "http://java.sun.com");
mainPanel.add(link);