Roman numerals to integers

Question

I have a transfer with products that unfortunately has to get matched by product name. The biggest issue here is I might get duplicate products on account of roman numbers.

Answer 1

private static HashMap romanMap = new HashMap<>() {{
    put('I', 1); put('V', 5); put('X', 10); put('L', 50); 
    put('C', 100); put('D', 500); put('M', 1000);
}};

private static int convertRomanToInt(String romanNumeral) {
    int total = 0;
    romanNumeral = romanNumeral.toUpperCase();

    //add every Roman numeral
    for(int i = 0; i < romanNumeral.length(); i++) {
        total += romanMap.get(romanNumeral.charAt(i));
    }

    //remove the Roman numerals that are followed 
    //directly by a larger Roman numeral
    for(int i = 0; i < romanNumeral.length()-1; i++) {
        if(romanMap.get(romanNumeral.charAt(i)) 
           < romanMap.get(romanNumeral.charAt(i+1))) {
           total -= 2* romanMap.get(romanNumeral.charAt(i));
        }
    }
    return total;
}

//note that the topmost solution does not solve this Roman numeral
//but mine does
//also note that this solution is a preference of simplicity over complexity
public static void main(String[] args) {
    String rn = "CcLXxiV"; //274
    System.out.println("Convert " + rn + " to " + convertRomanToInt(rn));
}