Generic Return Types

Question

Would there be a better way to write this getInput() method instead of checking for every single class that could be passed in?

    public Object getInput(String prompt, Class<?> type) {
        System.out.print(prompt);
        Scanner scn = new Scanner( System.in );
        String str = scn.nextLine( );
        if(type.equals(Integer.class))
            return Integer.parseInt(str);
        else if (type.equals(Double.class))
            return Double.parseDouble(str);
        else if (type.equals(Boolean.class))
            return Boolean.parseBoolean(str);
        else return type.cast(str);
    }

It works enough, but I would like to make it work with mostly all cases without having to add many more else if statements. As well as this, I am required to cast to that type when I take the input and assign it to a variable. Is there a way I could get around this?

Invocation:
int num = (int)menu.getInput("Enter an integer: ", Integer.class);

Answer 1

Maybe you can try to use reflection since these classes(Integer, Boolean...) usually have a static valueOf method:

    public static void main(String[] args) {
        int input = getInput("1", Integer.class);
        System.out.println(input);
    }

    public static <T> T getInput(String input, Class<T> type) {
        try {
            Method valueOf = type.getMethod("valueOf", String.class);
            return type.cast(valueOf.invoke(null, input));
        } catch (Exception e) {
            return null;
        }
    }