Hi everybody, i'm with some problems using composite id.

I have 3 tables:

City
--
idcity (PK)
name
--

Neighborhood
--
idcity (PK) (FK)
idneighbor (PK) (FK)
distance
--

Conditions
--
idconditions (PK)
idneighbor (FK)
status
--


My problem is that idcity and idneighbor are composite ids and foreign keys, in the same time, they're associated with idcity which is an PK in idcity.


My classes are:

public class Cidade {
private Integer idcidade;
private String nome;
private Set vizinhos;

//constructors and getters, setters
...
}

public class Vizinhanca {
private Integer id;
private Cidade cidade;
private Cidade vizinho;
private double distancia;

//constructors and getters, setters
...
}

public class Condicoes {
private Integer idcondicoes;
private Integer idvizinho;
private String status;

//constructors and getters, setters
...
}

public class CidadeCompositeId implements Serializable{

private Integer idcidade;
private Integer idvizinho;

public CidadeCompositeId() {
super();
}

public CidadeCompositeId(Integer idcidade, Integer idvizinho) {
super();
this.idcidade = idcidade;
this.idvizinho = idvizinho;
}

public Integer getIdcidade() {
return idcidade;
}

public void setIdcidade(Integer idcidade) {
this.idcidade = idcidade;
}

public Integer getIdvizinho() {
return idvizinho;
}

public void setIdvizinho(Integer idvizinho) {
this.idvizinho = idvizinho;
}

@Override
public int hashCode() {
//hashcode implementation
}

@Override
public boolean equals(Object obj) {
//equals implementation

}


My xml:

<hibernate-mapping package="com.maparot.model">

<class name="Cidade">

<id name="idcidade">
<generator class="increment"/>
</id>

<property name="nome"/>

<set name="vizinhos">
<key column="idcidade"/>
<one-to-many class="Vizinhanca"/>
</set>

</class>

</hibernate-mapping>


<class name="Vizinhanca">

<composite-id name="id" class="CidadeCompositeId">
<key-property name="idcidade"/>
<key-property name="idvizinho"/>
</composite-id>

<property name="distancia"/>

<many-to-one
name="cidade"
class="Cidade"
column="idcidade" insert="false" update="false"/>

<many-to-one
name="vizinho"
class="Cidade"
column="idcidade" insert="false" update="false"/>

</class>


And i got this error:

log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
Hibernate: select max(idcity) from City
Exception in thread "main" org.hibernate.id.IdentifierGenerationException: ids for this class must be manually assigned before calling save(): com.maparot.model.Neighborhood