Utility X, thenError

Zero system provide normalized way to build WebException Future, you can use the apis in current tutorial to process the response. The apis definition should be as following:

static <T, R> Future<R> thenError(
    final Future<Boolean> condition, 
    final Supplier<Future<T>> trueFuture, 
    final Function<T, R> trueFun, 
    final Class<? extends WebException> clazz, 
    final Object... args)
static Future<JsonObject> thenError(
    final Future<Boolean> condition, 
    final Supplier<Future<JsonObject>> trueFuture, 
    final Class<? extends WebException> clazz, 
    final Object... args)
static <T> Future<T> thenError(
    final Class<? extends WebException> clazz, 
    final Object... args)

1. Source Code

Source Code came from Video App

    public Function<SecUser, Future<JsonObject>> response(
            final String username,
            final String password,
            final Function<SecUser, Future<JsonObject>> future) {
        return pojo -> {
            if (null == pojo) {
                // User does not exist
                this.logger.info("[ Auth ] username/id = {0} does not exist.", username);
                return Ux.thenError(UserNotFoundException.class, this.clazz, username);
            } else if (!password.equals(pojo.getSPassword())) {
                // Password wrong
                this.logger.info("[ Auth ] username/id = {0}, password is wrong {1}.", username, password);
                return Ux.thenError(PasswordWrongException.class, this.clazz, username);
            } else {
                // Continue because of success
                this.logger.info("[ Auth ] User ( username/id = {0} ) login successfully.", username);
                return future.apply(pojo);
            }
        };
    }

Above function finished the task as:

• If returned SecUser pojo is null, reply to client UserNotFoundException Future.
• If the password is not match, reply to client PasswordWrongException Future.

2. Summary

Except direct to build standard WebException Future as example showed, there left two other apis to build conditional error Future, based on the arguments, you should know following workflow: