org.hibernate.LazyInitializationException associated collection

org.hibernate.LazyInitializationException associated collection

I have two model classes which are related by many-to-many relationships:
@Entity
@XmlRootElement
@DynamicInsert (value = true)
@DynamicUpdate (value = true)
public class Matchs {
@Id @GeneratedValue
private Long matchId;
private int size;
private Date begins;
private Date cutOff;
private BigDecimal buyIn;
@ManyToMany
private List<Users> users;
}
@Entity
@XmlRootElement
@DynamicInsert (value = true)
@DynamicUpdate (value = true)
public class Users {
@Id
private String username;
private String lastName,firstName,password,email;
private Date dateOfBirth;
@ManyToMany
private List<Matchs> matchs;
}
I'm using a DAO to get a Match with all associated Users:
public Matchs findMatchWithUsers(long matchId)
{
if (matchId <= 0)
throw new IllegalArgumentException("Match Id cannot be less than
or equal to zero");
try {
begin();
Matchs match = (Matchs) getSession().get(Matchs.class, matchId);
if (match != null)
Hibernate.initialize(match.getUsers());
commit();
close();
return match;
} catch (HibernateException e) {
rollback();
close();
throw e;
}
}
I then call a Jersey web service:
@GET
@Path ("getMatch/{matchId}")
@Produces (MediaType.APPLICATION_JSON)
public Response getMatchById (@PathParam ("matchId")long matchId)
{
MatchDAO matchDAO = DAO.getInstance(MatchDAO.class);
Matchs match = matchDAO.findMatchWithUsers(matchId);
if (match != null)
return Response.ok()
.entity(new
GsonBuilder().setPrettyPrinting().create().toJson(match))
.build();
return Response.status(Status.NOT_FOUND).entity("Match was not
located").build();
}
But this throws the following exception:
org.hibernate.LazyInitializationException: failed to lazily initialize a
collection of role: com.kyrogaming.models.Users.matchs, could not
initialize proxy - no Session
at
org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:566)
at
org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:186)
at
org.hibernate.collection.internal.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:545)
at
org.hibernate.collection.internal.AbstractPersistentCollection.read(AbstractPersistentCollection.java:124)
at
org.hibernate.collection.internal.PersistentBag.iterator(PersistentBag.java:266)
at
com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:95)
at
com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:60)
at
com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
at
com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:89)
at
com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:195)
at
com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
at
com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:96)
at
com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:60)
at
com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
at
com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:89)
at
com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:195)
at com.google.gson.Gson.toJson(Gson.java:593)
at com.google.gson.Gson.toJson(Gson.java:572)
at com.google.gson.Gson.toJson(Gson.java:527)
at com.google.gson.Gson.toJson(Gson.java:507)
at com.kyrogaming.services.MatchService.getMatchById(MatchService.java:77)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at
com.sun.jersey.spi.container.JavaMethodInvokerFactory$1.invoke(JavaMethodInvokerFactory.java:60)
at
com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$ResponseOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:205)
at
com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:75)
at
com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:288)
at
com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
at
com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:108)
at
com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
at
com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:84)
at
com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1469)
at
com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1400)
at
com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1349)
at
com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1339)
at
com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:416)
at
com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:537)
at
com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:699)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:565)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:479)
at
org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:119)
at
org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:521)
at
org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:227)
at
org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1031)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:406)
at
org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:186)
at
org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:965)
at
org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:117)
at
org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:111)
at org.eclipse.jetty.server.Server.handle(Server.java:349)
at
org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:449)
at
org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.headerComplete(AbstractHttpConnection.java:910)
at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:634)
at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:230)
at
org.eclipse.jetty.server.AsyncHttpConnection.handle(AsyncHttpConnection.java:76)
at
org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:609)
at
org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:45)
at
org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:599)
at
org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:534)
Where have I gone wrong because I really don't have a clue why the User
proxy objects are not initializing.
This is Abstract class is extended by All Hibernate DAO classes and
contains methods to interact with hibernate.
public abstract class AbstractHibernate <T>{
private SessionFactory sessionFactory;
private Session session;
@Inject
public void setSessionFactory (SessionFactory sessionFactory)
{
this.sessionFactory = sessionFactory;
}
protected Session getSession ()
{
if (sessionFactory == null)
throw new NullPointerException("SessionFactory null ");
if (session == null)
{
session = sessionFactory.openSession();
return session;
}
return session;
}
public void begin ()
{
getSession().beginTransaction();
}
public void commit () throws HibernateException
{
getSession().getTransaction().commit();
}
public void rollback ()
{
getSession().getTransaction().rollback();
}
protected void close ()
{
if (getSession () != null)
{
session.close();
session = null;
}
}