Open up a command prompt. In the command prompt type
Code:
firefox -new-tab http://www.google.com
Does that work for you? The code assumes that works for you (It works for me).
Because it looks like your system can't find Firefox (which I assumed you were using as your browser.)
If you are using Firefox, you'll need to do one of two things then, if it doesn't work. You could find the full path to your firefox installation and replace the call using the full path. You could change your PATH environment variable to include Firefox's path prior to running the program.
Because it works perfectly fine as-is (although slow) on Ubuntu using GCJ and a default Firefox install. It should work perfectly fine as-is on Windows using Oracle's Java and a recentish Firefox install as well. It should also work perfectly fine as-is on a Mac OSX which has some version of Java and a Firefox install.
Assuming Windows, pretend you installed firefox to C:\Browsers\Firefox (probably not, but for example). Then you'd do something like (in a command prompt)
Code:
PATH=%PATH%;C:\Browsers
or wherever the firefox.exe binary is actually installed to.
Then run the program from that same command prompt.
So the full sequence would look something like this
Code:
PATH=%PATH%;C:\wherevertheheckyouinstalledfirefox
javac URLReader.java
java URLReader
Wait a minute or two (since it's slow)
Results. :p