Java By Comparison

Split Method with Optional Parameters

class Logbook {

    static final Path CREW_LOG = Paths.get("/var/log/crew.log");

    List<String> readEntries(LocalDate date) throws IOException {
        final List<String> entries = Files.readAllLines(CREW_LOG,
                StandardCharsets.UTF_8);
        if (date == null) {
            return entries;
        }

        List<String> result = new LinkedList<>();
        for (String entry : entries) {
            if (entry.startsWith(date.toString())) {
                result.add(entry);
            }
        }
        return result;
    }
}

Booleans as you’ve seen them in ​Split Method with Boolean Parameters​ aren’t the only indicators of methods that do too much. Optional parameters have the same problem, but they’re harder to spot.

This time, we’re looking at how data ...