Use stream to filter data on the list collection of elements

List<VUsresrptitemcount> vusresrptitemcountList = map.get(tstudyroom.getName());

 List<VUsresrptitemcount> vusresrptitemcountList1= vusresrptitemcountList.stream().collect(
				      collectingAndThen(
				    	        toCollection(() ->new TreeSet<>(Comparator.comparing(o-> o.getrNumber()))), ArrayList::new)); 
				    	    			

The same data as rNumber is deduplicated