double保留位数

1.利用正则表达式可以保留任意位数

//double保留一位小数
public double oneAfterPoint(double d){
    String strD = String.valueOf(d*10);
    String[] strArr = strD.split("\\.");
    return Double.parseDouble(strArr[0])/10;
}

2.public static double formartDouble(double d){

double d = new BigDecimal(avgNmber).setScale(1, RoundingMode.UP).doubleValue()

}

3.get_double = Double.ParseDouble(String.format("%.2f",result_value));