Setup and validation

Validation at startup and in tests

sheetsmith:
  validation:
    packages: com.example.export

Every @ExcelSheet type under com.example.export is validated when the application starts; a mistake prevents the startup with the complete list of errors. For tests, see section 11.7.

Sheet names built from data

Names that come from data (customer names, categories) must be made valid by the caller, because sheetsmith rejects invalid names instead of changing them.

static String sheetName(String raw, Set<String> used) {
    String name = raw.replaceAll("[\\\\/?*\\[\\]:]", "_").strip();
    while (name.startsWith("'")) name = name.substring(1);
    while (name.endsWith("'")) name = name.substring(0, name.length() - 1);
    if (name.isEmpty()) name = "Sheet";
    if (name.length() > 31) name = name.substring(0, 31);
    if (name.equalsIgnoreCase("History")) name = "History_";
    String candidate = name;
    for (int i = 2; !used.add(candidate.toLowerCase(Locale.ROOT)); i++) {
        String suffix = " (" + i + ")";
        candidate = name.substring(0, Math.min(name.length(), 31 - suffix.length())) + suffix;
    }
    return candidate;
}

Plain Java with a dependency injection container

Sheetsmith sheetsmith = Sheetsmith.builder()
        .converterFactory(new CellConverterFactory() {
            @Override
            public <C extends CellConverter<?>> C create(Class<C> type) {
                return container.get(type);          // CDI, Guice, Dagger, ...
            }
        })
        .converter(Instant.class, new InstantConverter(ZoneId.of("UTC")))
        .defaults(new SheetsmithDefaults("dd/mm/yyyy", "dd/mm/yyyy hh:mm", "", TablePreset.MEDIUM, "#4472C4"))
        .build();