double取小数点后一位

if(checkVal == null){
				checkVal = "d";
			}

			if(checkVal.equals("b") || checkVal.equals("b,c") || checkVal.equals("a,b") || checkVal.equals("a,b,c")){

				
				double ywp = paperScores.getDoubleValue("1");
				String yvwen = jstuScore.getString("1");
				JSONObject jywscore = JSON.parseObject(yvwen);					
				String ywscore = "";
				if(yvwen == null){
					ywscore = "0";
				}else{
					ywscore = (jywscore.getString("stuScore")).toString();
				}
				double ywf = Double.valueOf(ywscore);
				double yws = (ywf/ywp)*100;
				BigDecimal bid =   new   BigDecimal(yws);
			    double yws1 = bid.setScale(1,BigDecimal.ROUND_HALF_UP).doubleValue();
				if(yvwen != null){
					jywscore.put("stuScore", yws1+"");
					jstuScore.put("1", jywscore);
					jStuScore.put("stuXkScoreAndRank", jstuScore);
				}