Simple Expression

import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;

public class SimpleExpression {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        String inputLine = input.nextLine().trim().replaceAll("\\s+","");
        String[] splitNums = inputLine.split("[-+]");
        String[] splitOperators = inputLine.split("[\\d\\s^.]");
        splitOperators = clean(splitOperators);
        splitNums = clean(splitNums);
        BigDecimal sum = new BigDecimal(splitNums[0]);

        for (int i = 1; i < splitNums.length; i++){
            BigDecimal temp = new BigDecimal(splitNums[i]);
            if (splitOperators[i-1].equals("+")){
                sum = sum.add(temp);
            }
            else{
                sum = sum.subtract(temp);
            }
        }
        System.out.printf("%.7f\n",sum);
    }

    public static String[] clean(final String[] v) {
    List<String> list = new ArrayList<String>(Arrays.asList(v));
    list.removeAll(Collections.singleton(""));
    return list.toArray(new String[list.size()]);
    }

}