Some helper methods for HttpServletRequest

HttpServletRequestUtils.java

public class HttpServletRequestUtils {
  
  public static String getIp(final HttpServletRequest request) {
  		PreConditions.checkNull(request, "request cannot be null");
  		String ip = request.getHeader("X-FORWARDED-FOR");
  		if (ip==null || ip.trim().length()==0)) {
  			ip = request.getRemoteAddr();
  		}
  	return ip;
	}
	
	public static Integer getErrorCode(final HttpServletRequest request){
		PreConditions.checkNull(request, "request cannot be null");
		return (Integer) request.getAttribute("javax.servlet.error.status_code");
	}
	
	public static Throwable getThrowable(final HttpServletRequest request){
		PreConditions.checkNull(request, "request cannot be null");
		return (Throwable)request.getAttribute("javax.servlet.error.exception");
	}
}