@Entity public class AnEntity
{
  // With property based access fields are not persistent themselves.
  private int someTransientField;
  private String someOtherTransientField;

  // Relationships among entities must be annotated.
  private Collection<AnotherEntity> relatedEntities;
  @OneToMany public Collection<AnotherEntity> getRelatedEntities ()
  {
    return (relatedEntities);
  }
  public void setRelatedEntities (Collection<AnotherEntity> entityCollection)
  {
    relatedEntities = entityCollection;
  }

  // Getter and setter methods for primary key.
  private long aKeyField;
  @Id Long getAKeyField () { return (aKeyField); }
  public void setAKeyField (Long aKeyField) { this.aKeyField = aKeyField; }

  // Obligatory constructor with no arguments
  public AnEntity () { ... }

  // Additional business methods ...
  public void myMethodOne (int iArgument) { ... }
  public int myMethodTwo (Object oArgument) { ... }
}