Weird Entity Manager Error

Question

I've made this query:

Usuario user1=(Usuario) request.getSession().getAttribute("user");
String query1 = "SELECT f FROM Favorito f WHERE f.usuarioBean = 'user1'";

I call the Manager method here

List<Favorito> favoritos = managerFavorito.getFavoritoByUser(query1);

And the Manager method looks like this:

public List<Favorito> getFavoritoByUser(String query1) {
        EntityManager em = getEntityManager();
        List<Favorito> results = null;
        try {
            Query query = em.createNativeQuery(query1);
            results = (List<Favorito>) query.getResultList();
        } finally {
            em.close();
        }
        return results;
    }

The error:

 org.apache.openjpa.persistence.ArgumentException: Metadata not found for type "class java.lang.String". Class not improved.

Full error :

[25/11/12 0:17:37:538 CET] 0000002b servlet       E com.ibm.ws.webcontainer.servlet.ServletWrapper service SRVE0068E: Se ha creado una excepción no detectada en uno de los métodos de servicio del servlet servletControl en la aplicación MotorSalesGR83.15. Excepción creada: <openjpa-2.0.2-SNAPSHOT-r422266:1032678 nonfatal user error> org.apache.openjpa.persistence.ArgumentException: No se han encontrado metadatos para el tipo "class java.lang.String". La clase no se ha mejorado.
    at org.apache.openjpa.meta.MetaDataRepository.getMetaDataInternal(MetaDataRepository.java:377)
    at org.apache.openjpa.meta.MetaDataRepository.getMetaData(MetaDataRepository.java:358)
    at org.apache.openjpa.jdbc.meta.MappingRepository.getMapping(MappingRepository.java:355)
    at org.apache.openjpa.jdbc.meta.strats.RelationStrategies.toDataStoreValue(RelationStrategies.java:88)
    at org.apache.openjpa.jdbc.meta.strats.RelationFieldStrategy.toDataStoreValue(RelationFieldStrategy.java:836)
    at org.apache.openjpa.jdbc.meta.FieldMapping.toDataStoreValue(FieldMapping.java:938)
    at org.apache.openjpa.jdbc.kernel.exps.PCPath.toDataStoreValue(PCPath.java:844)
    at org.apache.openjpa.jdbc.kernel.exps.Lit.calculateValue(Lit.java:109)
    at org.apache.openjpa.jdbc.kernel.exps.CompareEqualExpression.appendTo(CompareEqualExpression.java:98)
    at org.apache.openjpa.jdbc.kernel.exps.SelectConstructor.buildWhere(SelectConstructor.java:298)
    at org.apache.openjpa.jdbc.kernel.exps.SelectConstructor.evaluate(SelectConstructor.java:93)
    at org.apache.openjpa.jdbc.kernel.JDBCStoreQuery.createWhereSelects(JDBCStoreQuery.java:349)
    at org.apache.openjpa.jdbc.kernel.JDBCStoreQuery.executeQuery(JDBCStoreQuery.java:187)
    at org.apache.openjpa.kernel.ExpressionStoreQuery$DataStoreExecutor.executeQuery(ExpressionStoreQuery.java:776)
    at org.apache.openjpa.kernel.QueryImpl.execute(QueryImpl.java:1003)
    at org.apache.openjpa.kernel.QueryImpl.execute(QueryImpl.java:861)
    at org.apache.openjpa.kernel.QueryImpl.execute(QueryImpl.java:792)
    at org.apache.openjpa.kernel.DelegatingQuery.execute(DelegatingQuery.java:542)
    at org.apache.openjpa.persistence.QueryImpl.execute(QueryImpl.java:288)
    at org.apache.openjpa.persistence.QueryImpl.getResultList(QueryImpl.java:302)
    at entities.controller.FavoritoManager.getVehiculoFavorito(FavoritoManager.java:172)
    at tiw.servletControl.doPost(servletControl.java:78)
    at tiw.servletControl.doGet(servletControl.java:38)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:718)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:831)
    at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1657)
    at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:939)
    at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:502)
    at com.ibm.ws.webcontainer.servlet.ServletWrapperImpl.handleRequest(ServletWrapperImpl.java:179)
    at com.ibm.ws.webcontainer.webapp.WebApp.handleRequest(WebApp.java:3933)
    at com.ibm.ws.webcontainer.webapp.WebGroup.handleRequest(WebGroup.java:276)
    at com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:931)
    at com.ibm.ws.webcontainer.WSWebContainer.handleRequest(WSWebContainer.java:1583)
    at com.ibm.ws.webcontainer.channel.WCChannelLink.ready(WCChannelLink.java:186)
    at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleDiscrimination(HttpInboundLink.java:452)
    at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleNewRequest(HttpInboundLink.java:511)
    at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.processRequest(HttpInboundLink.java:305)
    at com.ibm.ws.http.channel.inbound.impl.HttpICLReadCallback.complete(HttpICLReadCallback.java:83)
    at com.ibm.ws.tcp.channel.impl.AioReadCompletionListener.futureCompleted(AioReadCompletionListener.java:165)
    at com.ibm.io.async.AbstractAsyncFuture.invokeCallback(AbstractAsyncFuture.java:217)
    at com.ibm.io.async.AsyncChannelFuture.fireCompletionActions(AsyncChannelFuture.java:161)
    at com.ibm.io.async.AsyncFuture.completed(AsyncFuture.java:138)
    at com.ibm.io.async.ResultHandler.complete(ResultHandler.java:204)
    at com.ibm.io.async.ResultHandler.runEventProcessingLoop(ResultHandler.java:775)
    at com.ibm.io.async.ResultHandler$2.run(ResultHandler.java:905)
    at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1604)

Something wrong? I'm starting to think I cannot search for row in Favorito using a simple Where.

Please post full stacktrace and show us where you got that exception — Rohit Jain, Nov 24 '12 at 23:32
The stack trace says that the exception is thrown by `entities.controller.FavoritoManager.getVehiculoFavorito(FavoritoManager.java:172)`, and not by the method above. — JB Nizet, Nov 25 '12 at 08:22

score 1 · Answer 1 · answered Nov 25 '12 at 09:51

There are some odd things going on in your code.

Firstly, you are pulling the user1 object out of the session, but never using it. Furthermore, in your query, you are asserting that f.usuarioBean is equal to the string 'user1', which i would imagine can never be true:

String query1 = "SELECT f FROM Favorito f WHERE f.usuarioBean = 'user1'";

I think you mean to do something like this:

String query1 = "SELECT f FROM Favorito f WHERE f.usuarioBean = '" + user1.getId() + "'";

An even better way to do this (really, the only right way to do this), would be to use a query parameter:

String query1 = "SELECT f FROM Favorito f WHERE f.usuarioBean = ?";
// and then later:
query.setParameter(1, user1);

Secondly, you're calling createNativeQuery, which takes an SQL query string as a parameter. However, the string you're passing isn't SQL, it's JPQL (you couldn't select a table alias in SQL, could you?). You should be calling createQuery, or better yet, the overload createQuery(String, Class), which creates a TypedQuery, for better type-safety.

Weird Entity Manager Error

1 Answers1