Validator

package com.corexis.calculator;

import java.util.HashMap;
import java.util.Map;

public class DataValidator {

    private int a, b;
    private String op;
    private boolean roman = false;

    Expression createExpression(String checkingString) {
        if (checkForNumbers(checkingString)) {
            return new Expression(a, b, op, roman);
        } else {
            return null;
        }

    }

    private String[] splitString(String str) {
        return str.split(" ");
    }

    private boolean checkForNumbers(String str) {
        boolean mAIsRoman = false;
        boolean mBIsRoman = false;
        String[] tempArr = splitString(str);
        try {
            this.a = Integer.parseInt(tempArr[0]);
        } catch (NumberFormatException e) {
            if (checkForRoman(tempArr[0]) != 0) {
                this.a = checkForRoman(tempArr[0]);
                mAIsRoman = true;
            } else {
                throw new NumberFormatException();
            }
        }
        try {
            this.b = Integer.parseInt(tempArr[2]);
        } catch (NumberFormatException e) {
            if (checkForRoman(tempArr[2]) != 0) {
                this.b = checkForRoman(tempArr[2]);
                mBIsRoman = true;
            } else {
                throw new NumberFormatException();
            }
        }
        if(mAIsRoman == mBIsRoman) {
            return true;
        } else {
            return false;
        }
    }

    private int checkForRoman(String checkingString) {
        if (Expression.romanNumbers.containsKey(checkingString)) {
            roman = true;
            return Expression.romanNumbers.get(checkingString);
        }
        return 0;
    }

    private boolean checkForOperation(String op) {
        return false;
    }


}