HTTP Status 500 - Não é possível criar instância para·a classe: br.com.lira.bean.EmpresaBean

[quote]

<!-- Implementação do JPA -->
<provider>org.hibernate.ejb.HibernatePersistenceProvider</provider>

<!-- Lista de entidades -->
<class>br.com.lira.modelo.Empresa</class> 
 <class>br.com.lira.modelo.Setor</class>
 <class>br.com.lira.modelo.Onibus</class>
 <exclude-unlisted-classes>true</exclude-unlisted-classes> 

<properties>


  <!-- Propriedades JDBC -->
  <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
  <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost/tcc?autoReconnect=true"/>
  <property name="javax.persistence.jdbc.user" value="lira"/>
  <property name="javax.persistence.jdbc.password" value="lira"/>
      
    
  <!-- Configurações específicas do Hibernate -->
  <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5InnoDBDialect"/>
  <property name="hibernate.hbm2ddl.auto" value="validate"/>
  <property name="hibernate.show_sql" value="true"/>
  <property name="hibernate.format_sql" value="true"/>
  
  <property name="hibernate.connection.autoReconnect" value = "true" />
  <property name="hibernate.connection.autoReconnectForPools" value = "true" />
  <property name="hibernate.connection.is-connection-validation-required" value = "true" />
  <property name="hibernate.archive.autodetection" value="class, hbm"/>
  
</properties>

private static EntityManagerFactory emf ;

static{
	if(emf == null){
		emf = Persistence.createEntityManagerFactory("meuPU");
	}	
}

public static EntityManager getEntityManager(){
	return emf.createEntityManager();
}