How do I keep a session alive for long selenium scripts in automation?

See more:

Java

selenium

WebDriver

I am automating a task with Selenium in which while automating long scripts my session got expired and the page automatically get jumped to login page , (Developer is maintaining page session for 60 minutes at server side) . Please guide me if there is any way to maintain the session for as long as my script keeps running .

I tried using using cookies but null is received in output , seems like it does not work for me .

What I have tried:

driver.get(url);
Set<cookie> cookies =driver.manage().getCookies();

System.out.println("Cookies" + driver.manage().getCookies().toString());
for(Cookie ck : driver.manage().getCookies())                            
{ 	  	   System.out.println((ck.getName()+";"+ck.getValue()+";"+ck.getDomain()+";"+ck.getPath()+";"+ck.getExpiry()+";"+ck.isSecure()));                                                                                                    
}