Change character value RegEx in java

Question

I need to use '+' character instead of '|' character in regular expression in java. So , if i write something like 0+1 regular expresion 0 "or" 1 input should be accepted. '+' sign should references "OR" operation instead of '|'. How can i do this?

Answer 1

So you will need to create your own automata for regex, what is way to complex... or you just need to do a replace into your string before you call the mathes regex method.

public static void main(String[] args) {
    String regex = "0+1".replaceAll("\\+", "|");
    System.out.println("0".matches(regex));
}

but i had to say that is a door for a lot of bugs.