Newline in JLabel

113
votes

How can I display a newline in JLabel?

For example, if I wanted:

Hello World!
blahblahblah

This is what I have right now:

JLabel l = new JLabel("Hello World!\nblahblahblah", SwingConstants.CENTER);

This is what is displayed:

Hello World!blahblahblah

Forgive me if this is a dumb question, I'm just learning some Swing basics...

6
javauser-interfaceswingformattingjlabel
Definitely not a dumb question. Took me a while to figure out html was possible in swing too. - Simon Baars

6 Answers

187
votes

Surround the string with <html></html> and break the lines with <br/>.

JLabel l = new JLabel("<html>Hello World!<br/>blahblahblah</html>", SwingConstants.CENTER);
12
votes

You can try and do this:

myLabel.setText("<html>" + myString.replaceAll("<","&lt;").replaceAll(">", "&gt;").replaceAll("\n", "<br/>") + "</html>")

The advantages of doing this are:

  • It replaces all newlines with <br/>, without fail.
  • It automatically replaces eventual < and > with &lt; and &gt; respectively, preventing some render havoc.

What it does is:

  • "<html>" + adds an opening html tag at the beginning
  • .replaceAll("<", "&lt;").replaceAll(">", "&gt;") escapes < and > for convenience
  • .replaceAll("\n", "<br/>") replaces all newlines by br (HTML line break) tags for what you wanted
  • ... and + "</html>" closes our html tag at the end.

P.S.: I'm very sorry to wake up such an old post, but whatever, you have a reliable snippet for your Java!

3
votes

You can use the MultilineLabel component in the Jide Open Source Components.

http://www.jidesoft.com/products/oss.htm

2
votes

You can do

JLabel l = new JLabel("<html><p>Hello World! blah blah blah</p></html>", SwingConstants.CENTER);

and it will automatically wrap it where appropriate.

2
votes

Thanks Aakash for recommending JIDE MultilineLabel. JIDE's StyledLabel is also enhanced recently to support multiple line. I would recommend it over the MultilineLabel as it has many other great features. You can check out an article on StyledLabel below. It is still free and open source.

http://www.jidesoft.com/articles/StyledLabel.pdf

1
votes

JLabel is actually capable of displaying some rudimentary HTML, which is why it is not responding to your use of the newline character (unlike, say, System.out).

If you put in the corresponding HTML and used <BR>, you would get your newlines.