import java.util.regex.Pattern; import java.util.regex.Matcher; public class Regex { public static void main(String[] args) { Pattern pattern = Pattern.compile("a*b"); Matcher matcher1 = pattern.matcher("aaaab"); Matcher matcher2 = pattern.matcher("aaaabbb"); System.out.println(matcher1.matches()); System.out.println(matcher2.matches()); } }