Java 获取当前页面完整的url

HttpServletRequest httpRequest=(HttpServletRequest)request;
        

String strBackUrl = "http://" + request.getServerName() //服务器地址
                    
+ ":" 
                    
+ request.getServerPort()//端口号
                    
+ httpRequest.getContextPath()      //项目名称
                   
 + httpRequest.getServletPath()      //请求页面或其他地址
        	   
 + "?" + (httpRequest.getQueryString()); //参数