java正则表达式来发现正则表达式

Question

I would like to build regular expression which checks if entered string is regular expression so if it contains | , [ and then ] , ( and then ) for example:

A0[1-4].*Done or (L1 | L2).*Done'

I've build something simple like this: ".[\\\\[]..[\\\\]]" but it doesn't work at all even for simple examples. I tried with Java matcher and just simple String.matches()

Answer 1

You can use Java own parser to check if the input is regular expression or not:

public boolean isRegExp(String pattern) {
    try {
        Pattern.compile(pattern);
        return true;
    }
    catch(PatternSyntaxException ex) {
        return false;
    }
}