The solution

You must code retrievals of your entity on your entity DAO API, not on the entity itself.

A singleton read method must return your entity API, and should specify that null will be returned if no matching entity instance is found:

Figure 1. DAO interface declaration for a singleton read

/**
   * Reads the instance with the specified name.
   *
   * @param name
   *          the name to find
   * @return the instance with the specified name, or null if not
   *         found.
   */
  public MyNewEntity readByName(final String name);

A search method (which can return zero, one or many instances) must return a collection of your entity API (typically a Set):

Figure 2. DAO interface declaration for a search

/**
   * Searches all the instances which have the specified type.
   *
   * @param type
   *          the type to search for
   * @return all the instances which have the specified type, or an
   *         empty set if none found.
   */
  public Set<MyNewEntity> searchByType(
      final MYNEWENTITYTYPEEntry type);

Your method names must follow the naming standards for modeled entity operations.

Use entity APIs in preference to passing primary keys, e.g. do this:

Figure 3. DAO interface taking an entity instance as a parameter

/**
   * Searches all the instances belonging to the specified parent.
   *
   * @param myParentEntity
   *          the parent to search for
   * @return all the instances belonging to the specified parent, or
   *         an empty set if none found.
   */
  public Set<MyNewEntity> searchByParent(
      final MyParentEntity myParentEntity);

not this:

Figure 4. Incorrect - DAO interface taking an entity ID value as a parameter

/** ********** VERY VERY BAD - DO NOT DO THIS! ********** */
  /**
   * Searches all the instances which have the specified parent ID.
   *
   * @param myParentEntityID
   *          the parent ID to search for
   * @return all the instances which have the specified parent ID,
   *         or an empty set if none found.
   */
  public Set<MyNewEntity> searchByParentID(
      final Long myParentEntityID);
  /** ********** VERY VERY BAD - DO NOT DO THIS! ********** */