JPA Entity + JSON serialization

Hello,

Actually im using a JPA specification and is required to serialize these objects to JSON notation (View).
When i try to serialize a object to JSON in the middle of the transaction a ClassCastException is throw.
The context :

First my Entity class

@Entity
public class CatalogoDeProdutos implements java.io.Serializable {

@Id
@GeneratedValue(strategy=GenerationType.AUTO)
@XStreamAlias("idCatalogo")
private Long idCatalogo;

@Column
@XStreamAlias("descricao")
private String descricao;

@OneToMany(cascade=CascadeType.ALL,fetch=FetchType.LAZY)
private List<Produto> produtos;

@XStreamAlias("tipo")
@Enumerated(EnumType.STRING)
private TipoDoCatalogo tipo;

gets sets ......

...
CatalogoDeProdutos cp = new CatalogoDeProdutos();

aa = JSONSerializationHelper.getJSONFromObject("a", CatalogoDeProdutos.class, cp.clone());

System.out.print("Entity class with annotation"+aa.toString());
....

public static JSONObject getJSONFromObject(String alias,Class c,Object o) throws JSONException, ClassNotFoundException

{ xstream= new XStream(new JettisonMappedXmlDriver()); xstream.alias(alias, c.getClass()); String jr = xstream.toXML(c.cast(o)); JSONObject js = new JSONObject(jr); xstream = null; jr = null; return js; }

Work's fine out of the transaction and results

Entity class with annotation {"net.cjb.malacma.nemesis2web.model.CatalogoDeProdutos":{"idCatalogo":"-1","produtos":"","tipo":"CATALOGO_VENDAS"}}

then....

in the middle of the transaction i've cloned the object to the serialization and the folllowing exception is throw.....

java.lang.ClassCastException: org.codehaus.jettison.json.JSONArray
cannot be cast to org.codehaus.jettison.json.JSONObject
org.codehaus.jettison.mapped.MappedXMLStreamWriter.writeAttribute(MappedXMLStreamWriter.java:93)
org.codehaus.jettison.mapped.MappedXMLStreamWriter.writeAttribute
(MappedXMLStreamWriter.java:130)
org.codehaus.jettison.mapped.MappedXMLStreamWriter.writeAttribute(MappedXMLStreamWriter.java:134)
com.thoughtworks.xstream.io.xml.StaxWriter.addAttribute(StaxWriter.java:86)
com.thoughtworks.xstream.io.WriterWrapper.addAttribute
(WriterWrapper.java:30)
com.thoughtworks.xstream.converters.reflection.SerializableConverter$1.defaultWriteObject(SerializableConverter.java:146)
com.thoughtworks.xstream.converters.reflection.SerializableConverter.doMarshal
(SerializableConverter.java:201)
com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.marshal(AbstractReflectionConverter.java:43)
com.thoughtworks.xstream.core.AbstractReferenceMarshaller.convert
(AbstractReferenceMarshaller.java:55)
com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:50)
com.thoughtworks.xstream.annotations.AnnotationReflectionConverter.marshallField(AnnotationReflectionConverter.java
:46)
com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter$2.writeField(AbstractReflectionConverter.java:112)
com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter$2.visit
(AbstractReflectionConverter.java:88)
com.thoughtworks.xstream.converters.reflection.PureJavaReflectionProvider.visitSerializableFields(PureJavaReflectionProvider.java:117)
com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.doMarshal
(AbstractReflectionConverter.java:73)
com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.marshal(AbstractReflectionConverter.java:43)
com.thoughtworks.xstream.core.AbstractReferenceMarshaller.convert
(AbstractReferenceMarshaller.java:55)
com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:50)
com.thoughtworks.xstream.core.TreeMarshaller.start(TreeMarshaller.java:73)
com.thoughtworks.xstream.core.ReferenceByXPathMarshallingStrategy.marshal
(ReferenceByXPathMarshallingStrategy.java:34)
com.thoughtworks.xstream.XStream.marshal(XStream.java:765)
com.thoughtworks.xstream.XStream.marshal(XStream.java:754)
com.thoughtworks.xstream.XStream.toXML(XStream.java
:735)
com.thoughtworks.xstream.XStream.toXML(XStream.java:725)
net.cjb.malacma.nemesis2web.helper.JSONSerializationHelper.getJSONFromObject(JSONSerializationHelper.java:37)
net.cjb.malacma.nemesis2web.bo.ControleDeProduto.findCatalogoFull
(ControleDeProduto.java:65)
net.cjb.malacma.nemesis2web.facade.MDIFacadeSistema.findCatalogoFull(MDIFacadeSistema.java:878)
net.cjb.malacma.nemesis2web.mvc.control.ProdutoController.handleRequest(ProdutoController.java
:41)
org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:48)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:819)
org.springframework.web.servlet.DispatcherServlet.doService
(DispatcherServlet.java:754)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:399)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:354)
javax.servlet.http.HttpServlet.service
(HttpServlet.java:690)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:390)

Any ideia? Thanks for reading this!