用DecimalFormat：

double d = 1.0E7;

System.out.println(new DecimalFormat("#").format(d));

    /**取小数点位数补0

     * セルの書式(Format)

     * @param webFilePath

     */

    private String SetFormat(double maxValue){

        Integer Maxlenth = ;

        StringBuilder value = new StringBuilder();

        if(maxValue !=){

            DecimalFormat decimalFormat = new DecimalFormat("###############.########");

            String strmaxValue =  decimalFormat.format(maxValue);

            String strpoint[]  =  strmaxValue.split("\\.");

            if(strpoint.length >){

                int aaa =  strpoint[].length();

                //Maxlenth =   (maxValue+"").length()-(maxValue+"").indexOf(".")-1;

                Maxlenth = aaa;

            }

        }

        if(Maxlenth >  ){

            for (int j = ; j < Maxlenth; j++)

            {

                if(j==){

                    value.append(".0");

                }else{

                    value.append("");

                }

            }

        }

        return value.toString();

    }