Regex Optimization for large lists

Question

I am comparing two lists of strings to find possible matches. Example:

public class Tester {

    public static void main(String[] args) {

        List

        

Answer 1

IMHO methods like String.matches(String) should be forbidden. Maybe you need a regex match, maybe not, but what happens here, is that you string gets compiled into an regex... again and again.

So do yourself a favor and convert then all into regexes via Pattern.compile and reuse them.

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Looking at your ".*" + s2 + ".*", I'd bet you need no regex at all. Simply use String.contains and enjoy the speed.