Reading web site using java.net.Url

[Sergei]

Hi,
I am experiencing problem with reading Web page using java.net.Url
Code is working for some webs but for some others it gives me
Filenotfoundexception when I am getting inputstream connection.getInputStream()
I understand that it something to deal with checking on web server side
May be checking headers for browser may be something else.

BTW when I tried the same URL that given me exception from computer through
Firewall I was able to get response.

Question.

How to overcome this problem without hiding behind firewall is there way
to completely simulate browser when you reading from java class?

Thank you,
Sergei