Java中Double類型的加減 - Java

使用平常加減出現的bug:

解決方法:

public static Double BigDecimalCal(Double d1,String operation,Double d2){
        BigDecimal bd = new BigDecimal("0");
        if(d1!=null && d2!=null){
            if("+".equals(operation)){
                bd = new BigDecimal(String.valueOf(d1)).add(new BigDecimal(String.valueOf(d2)));
            }else if("-".equals(operation)){
                bd = new BigDecimal(String.valueOf(d1)).subtract(new BigDecimal(String.valueOf(d2)));
            }else if("*".equals(operation)){
                bd = new BigDecimal(String.valueOf(d1)).multiply(new BigDecimal(String.valueOf(d2)));
            }else if("/".equals(operation)){
                bd = new BigDecimal(String.valueOf(d1)).divide(new BigDecimal(String.valueOf(d2)),6,RoundingMode.HALF_UP);
            }
        }
        return bd.doubleValue();
    }
    
    public static String BigDecimalCal(String d1,String operation,String d2){
        BigDecimal bd = new BigDecimal("0");
        if(d1!=null && d2!=null){
            if("+".equals(operation)){
                bd = new BigDecimal(d1).add(new BigDecimal(d2));
            }else if("-".equals(operation)){
                bd = new BigDecimal(d1).subtract(new BigDecimal(d2));
            }else if("*".equals(operation)){
                bd = new BigDecimal(d1).multiply(new BigDecimal(d2));
            }else if("/".equals(operation)){
                bd = new BigDecimal(d1).divide(new BigDecimal(d2),6,RoundingMode.HALF_UP);
            }
        }
        return bd.toString();
    }      

應用:

Double rate1 = Double.parseDouble(rowData[1]);
  Double rate2 = Double.parseDouble(rowData[2]);
  // rate1*rate2, 如果是rate1-rate2, 隻需改為 '-' 即可
  Double depX1 = PubFun.BigDecimalCal(rate1, "*", rate2);