Java处理科学计数法数字方式

BigDecimal bd = new BigDecimal("1.23E+5");

String str = bd.toPlainString();

double num = Double.parseDouble(str);

String sciNum = "1.23E+5";
BigDecimal bd = new BigDecimal(sciNum);
String plainStr = bd.toPlainString();
double num = Double.parseDouble(plainStr);
System.out.println(num);

package com.yunlu.groundwater.constants;
import com.yunlu.groundwater.gwParameters.entities.*;
import java.util.HashMap;
import java.util.Map;
public class Const {

    // tpl
    public static final String TPL_E1 = "%s+%s";

    // fmt
    public static final String FMT_DOUBLE = "0.00E00";
}

/**
     * @param val 数值
     * @return 返回科学计数法字符串
     */
    public static String scientificNotationString(Double val) {
        String res = new DecimalFormat(Const.FMT_DOUBLE).format(val);
        if (val >= 1) {
            int length = res.length();
            String prefix = res.substring(0, length-2);
            String suffix = res.substring(length-2, length);
            res = String.format(Const.TPL_E1, prefix, suffix);
        }
        return res;
    }