Java regex for matching keywords

Try this.

public static void main(String[] args) {
    String largeString = "When I was little I had an Aston-Martin car door slammed shut on my hand and I still remember it quite vividly.";
    List<String> keywords = List.of("was", "had", "Martin", "shut", "hen", "ttle", "ar");
    Pattern pat = Pattern.compile(keywords.stream()
        .collect(Collectors.joining("|", "\S*(", ")\S*")), Pattern.CASE_INSENSITIVE);
    Matcher m = pat.matcher(largeString);
    while (m.find())
        System.out.println(m.group());
}

output:

When
was
little
had
Aston-Martin
car
shut