Examples with PersistentDataStoreException codeu.model.store.persistence.PersistentDataStoreException used on opensource projects

Example 6 with PersistentDataStoreException

use of codeu.model.store.persistence.PersistentDataStoreException in project CodeU-Spring-2018 by jwang281.

the class PersistentDataStore method loadUsers.

/**
 * Loads all User objects from the Datastore service and returns them in a List.
 *
 * @throws PersistentDataStoreException if an error was detected during the load from the
 *     Datastore service
 */
public List<User> loadUsers() throws PersistentDataStoreException {
    List<User> users = new ArrayList<>();
    // Retrieve all users from the datastore.
    Query query = new Query("chat-users");
    PreparedQuery results = datastore.prepare(query);
    for (Entity entity : results.asIterable()) {
        try {
            UUID uuid = UUID.fromString((String) entity.getProperty("uuid"));
            String userName = (String) entity.getProperty("username");
            String password = (String) entity.getProperty("password");
            Instant creationTime = Instant.parse((String) entity.getProperty("creation_time"));
            User user = new User(uuid, userName, password, creationTime);
            users.add(user);
        } catch (Exception e) {
            // database entity definition mismatches, or service mismatches.
            throw new PersistentDataStoreException(e);
        }
    }
    return users;
}