GWT request factory twig locator

gistfile1.java

/**
 * Objects implementing this interface can be located by {@link TwigEntityLocator}.
 */
public interface Entity {
  /**
   * Gets object id.
   *
   * @return object id.
   */
  Long getId();

  /**
   * Get version.
   *
   * @return version number.
   */
  Integer getVersion();
}


public class TwigEntityLocator extends Locator<Entity, Long> {

  private Provider<ObjectDatastore> datastore;

  @Inject
  public TwigEntityLocator(Provider<ObjectDatastore> datastore) {
    this.datastore = datastore;
  }

  @Override
  public Entity create(Class<? extends Entity> clazz) {
    try {
      return clazz.newInstance();
    } catch (InstantiationException e) {
      e.printStackTrace();
    } catch (IllegalAccessException e) {
      e.printStackTrace();
    }
    return null;
  }

  @Override
  public Entity find(Class<? extends Entity> clazz, Long id) {
    return datastore.get().load(clazz, id);
  }

  @Override
  public Class<Entity> getDomainType() {
    return Entity.class;
  }

  @Override
  public Long getId(Entity domainObject) {
    return  domainObject.getId();
  }

  @Override
  public Class<Long> getIdType() {
    return Long.class;
  }

  @Override
  public Integer getVersion(Entity domainObject) {
    return domainObject.getVersion();
  }
}