import java.util.*;
import java.text.*;
import java.math.BigDecimal;

public class FormatBigDecimal {

    public static void main(String[] args) {
        Locale.setDefault(new Locale("nl", "NL"));
        String nl_NL_BigDecimal = "343.298.723.948.729.384.091.826.095.842.735.093,09324798"; //This is a valid number in nl_NL...
        BigDecimal bLoc = getBigDecimalLocalised(nl_NL_BigDecimal, Locale.getDefault());
        System.out.println(bLoc);
    }

    public static BigDecimal getBigDecimalLocalised(String value, Locale locale) {
        DecimalFormatSymbols dfs = new DecimalFormatSymbols(locale);
        char sep = dfs.getDecimalSeparator();
        char gp = dfs.getGroupingSeparator();
        StringBuilder sb = new StringBuilder(value);
        for(int i = sb.length() - 1;i >=0;i--) {      
            if (sb.charAt(i) == gp) {
                sb.deleteCharAt(i);
            }
            else if (sb.charAt(i) == sep) {
                sb.setCharAt(i, '.');
            }
        }
        return new BigDecimal(sb.toString());
    }
}