FULL PRODUCT VERSION :
jre7u2

ADDITIONAL OS VERSION INFORMATION :
Same problem on Mac OS X Lion, Windows 7 and Debian GNU/LINUX squeeze .

A DESCRIPTION OF THE PROBLEM :
I'm trying to load an HTML file that is large approximately 2MB (1927KB for the sake of precision) into a JEditorPane, and it takes about 65 seconds, it seems to be a bug of the JTextPane/JEditorPane.

I got these loading times result :

Set the html content(1927KB) of the Preview pane, loading time=68230ms
Set the html content(1927KB) of the Preview pane, loading time=62693ms
Set the html content(1927KB) of the Preview pane, loading time=66583ms

More Information here : http://stackoverflow.com/questions/9046365/jeditorpane-settext-2mb-html-terrible-performance-65-seconds

and here :

https://forums.oracle.com/forums/thread.jspa?threadID=2340546&tstart=0

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
- Load and html of 2mb or more into a string
- set as a content of a JEditorPane with setText() method.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The same HTML file loaded into a web browser get loaded in less than 2 seconds.

65 seconds to load 2Mb of html is too much .
ACTUAL -
JEditorPane take near 65 seconds to load the html string into the pane ... Too much time .

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
final String htmlContent = //Load a 2MB String
previewPane.setContentType("text/html; charset=UTF-8");
previewPane.setText(htmlContent);
---------- END SOURCE ----------

SUPPORT :
YES