Question

This method invokes different validation methods for every textfield in a form and the int[] array in the Map decides which methods or what type of validations is to be done on a textfield. But this method has cyclomatic complexity of 10. Please suggest any better alternatives or what can be done to improve this code ?

public final boolean validateFields(final HashMap<JTextField, int[]> textFieldMap) {
        boolean flag = false;
        for (Map.Entry<JTextField, int[]> entry : textFieldMap.entrySet()) {
            JTextField field = entry.getKey();
            for (int constant : entry.getValue()) {
                switch (constant) {
                    case Constants.VAL_CHAR : flag = validateChar();
                        break;
                    case Constants.VAL_DATE : flag = validateDate();
                        break;
                    case Constants.VAL_DUPLICATE : flag = validateDuplicate();
                        break;
                    case Constants.VAL_EMAIL : flag = validateEmail();
                        break;
                    case Constants.VAL_LENGTH : flag = validateLength();
                        break;
                    case Constants.VAL_NUMERIC : flag = validateNumeric();
                        break;
                    case Constants.VAL_STRING : flag = validateNumeric();
                        break;
                    default : flag = validateNotNull();
                        break;
                }
            }
        }
        return flag;
    }

Answer 1

I don’t know if this is applicable to your case, but you could use an enum instead of int constants:

public enum Constants {

    VAL_CHAR {
        public boolean validate() {
            return validateChar();
        }
    },
    VAL_DATE {
        public boolean validate() {
            return validateDate();
        }
    },
    ...
    ;

    public abstract boolean validate();

}

You can then refactor your code like this:

public final boolean validateFields(final HashMap<JTextField, int[]> textFieldMap) {
    boolean flag = false;
    for (Map.Entry<JTextField, int[]> entry : textFieldMap.entrySet()) {
        JTextField field = entry.getKey();
        for (int constant : entry.getValue()) {
            Constants enumConstant = ...; //mapping from int if you need to keep ints
            flag = enumConstant.validate();
        }
    }
    return flag;
}

Or just get rid of the ints:

public final boolean validateFields(final HashMap<JTextField, Constants[]> textFieldMap) {
    boolean flag = false;
    for (Map.Entry<JTextField, Constants[]> entry : textFieldMap.entrySet()) {
        JTextField field = entry.getKey();
        for (Constants constant : entry.getValue()) {
            flag = constant.validate();
        }
    }
    return flag;
}

PS: in your current code, you probably mean flag = flag && validateXXX() unless you only want to return the flag corresponding to the last checked field.