Erro no OneToOne

Estou tentando fazer um mapeamento com o OneToOne mais está sendo gerado um erro inesperado, esse relacionamento é entre o colaborador e o login. observe as classes de persistencias abaixo junto com os mapeamentos utilizados

@Entity
@Table(name = "login")
public class Login {
	
	@EmbeddedId
	private IdLogin idLogin;	
	
	private String Log_permissao;

###############################

@Entity
@Table(name = "colaborador")
public class Colaborador implements Serializable{

      	 private Long Col_codigo;
	 private String Col_nome;
	 private String Col_funcao;
	 private String Col_fone;

        public Colaborador(){
		
	}	

#########################################


@Embeddable //Esta anotação indica que esta classe é um componete de outra, muito utilizado para representar um CHAVE COMPOSTA
public class IdLogin implements Serializable{	
	
	@Column(name = "Log_nome", nullable = false)
	private String Log_nome;
	
	@Column(name = "Log_senha", nullable = false)
	private String Log_senha;
	
	@OneToOne
	@JoinColumn(name="Log_Col_codigo", insertable = true, updatable = true, nullable = false)  		
	private Colaborador colaborador;

################################################

ESSE ERRO É GERADO

log4j:WARN No appenders could be found for logger (org.hibernate.cfg.annotations.Version).
log4j:WARN Please initialize the log4j system properly.
Exception in thread "AWT-EventQueue-0" java.lang.ExceptionInInitializerError
	at src.portaria.utils.ConnectDB.<clinit>(ConnectDB.java:24)
	at src.portaria.dao.LoginDAO.consultarRegistoPorParametros(LoginDAO.java:21)
	at src.portaria.gui.Tela_login.bentrar(Tela_login.java:191)
	at src.portaria.gui.Tela_login$1.actionPerformed(Tela_login.java:135)
	at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
	at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
	at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
	at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
	at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
	at java.awt.Component.processMouseEvent(Unknown Source)
	at javax.swing.JComponent.processMouseEvent(Unknown Source)
	at java.awt.Component.processEvent(Unknown Source)
	at java.awt.Container.processEvent(Unknown Source)
	at java.awt.Component.dispatchEventImpl(Unknown Source)
	at java.awt.Container.dispatchEventImpl(Unknown Source)
	at java.awt.Component.dispatchEvent(Unknown Source)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
	at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
	at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
	at java.awt.Container.dispatchEventImpl(Unknown Source)
	at java.awt.Window.dispatchEventImpl(Unknown Source)
	at java.awt.Component.dispatchEvent(Unknown Source)
	at java.awt.EventQueue.dispatchEvent(Unknown Source)
	at java.awt.EventDispatchThread.pumpOneEventForHierarchy(Unknown Source)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
	at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.awt.EventDispatchThread.run(Unknown Source)
Caused by: java.lang.NullPointerException
	at org.hibernate.cfg.AnnotationBinder.bindOneToOne(AnnotationBinder.java:1867)
	at org.hibernate.cfg.AnnotationBinder.processElementAnnotations(AnnotationBinder.java:1286)
	at org.hibernate.cfg.AnnotationBinder.fillComponent(AnnotationBinder.java:1662)
	at org.hibernate.cfg.AnnotationBinder.bindId(AnnotationBinder.java:1695)
	at org.hibernate.cfg.AnnotationBinder.processElementAnnotations(AnnotationBinder.java:1171)
	at org.hibernate.cfg.AnnotationBinder.bindClass(AnnotationBinder.java:706)
	at org.hibernate.cfg.AnnotationConfiguration.processArtifactsOfType(AnnotationConfiguration.java:452)
	at org.hibernate.cfg.AnnotationConfiguration.secondPassCompile(AnnotationConfiguration.java:268)
	at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1210)
	at src.portaria.utils.ConnectDB.<clinit>(ConnectDB.java:22)
	... 27 more

##############################################################################

Sendo assim não consigo nem conectar com o banco tenho certeza que tem alguma coisa errada com anotação, mais o que estou fazendo de errado
já consegui mapear um relacionamento ternário mais estou apanhado para o OneToOne.

Pesso a ajuda de todos! estou aguardando. Obrigado!

Será que é tão dificil assim mapear o OneToOne? Qualquer contribuição será de grande valia

Gostaria de contar com a colaboração de todos para ajudar a solucionar essa situação"!

Desde já agradeço :!: