Java remove duplicated array : how to remove the duplicated entry from this array code:

    Iterator<IHTTPStreamerSession> iterHttp = httpSessions.iterator();
    while(iterHttp.hasNext())
    {
	IHTTPStreamerSession httpSession = iterHttp.next();
	if (httpSession == null)
	continue;
										
	ret.append("<HTTPSession>");
	ret.append("<IpAddress>"+httpSession.getIpAddress()+"</IpAddress>");
	ret.append("<TimeRunning>"+httpSession.getTimeRunningSeconds()+"</TimeRunning>");
									
	ret.append("</HTTPSession>");
    }

I need to generate only 1 entry for each < IpAddress >