Why EAGER takes time to get result and LAZY causes exception?

Question

I'm trying to get the list of Review of a Movie, when I'm trying to use the FetchType Lazy on Review class It causes LazyInitializationException , When I'm trying @ManyToOne(fetch = FetchType.EAGER) the query is slow and takes time to return results

@Entity
@Table(name = "REVIEW")
public class Review  implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO, generator = "REVIEW_SEQ")
    @SequenceGenerator(name = "REVIEW_SEQ", sequenceName = "REVIEW_SEQ", allocationSize = 1)
    @Column(name = "ID", length = 15)
    private Long id;
    @ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    @JoinColumn(name = "FK_ID_MOVIE", referencedColumnName = "ID_Movie", nullable = false)
    private Movie refMovie;

    //Other properties

    }


@Entity
@Table(name = "MOVIE")
public class Movie implements Serializable {

    private static final long serialVersionUID = 1L;


    @OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    @JoinColumn(name = "FK_ID_MOVIE", referencedColumnName = "ID_MOVIE", nullable = true, insertable = true, updatable = true)
    private List<Review> refReview;

It causes :

[org.apache.cxf.phase.PhaseInterceptorChain] (default task-1) Application has thrown exception, unwinding now: org.hibernate.LazyInitializationException: could not initialize proxy - no Session
14:01:49,323 INFO  [org.apache.cxf.phase.PhaseInterceptorChain] (default task-1) Application has thrown exception, unwinding now: org.hibernate.LazyInitializationException: could not initialize proxy - no Session
14:01:49,324 WARNING [org.apache.cxf.phase.PhaseInterceptorChain] (default task-1) Exception in handleFault on interceptor org.apache.cxf.binding.xml.interceptor.XMLFaultOutInterceptor@108dab92: org.apache.cxf.interceptor.Fault: could not initialize proxy - no Session
    at org.apache.cxf.service.invoker.AbstractInvoker.createFault(AbstractInvoker.java:148)
    at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:114)
    at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:130)
    at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:82)
    at org.apache.cxf.interceptor.ServiceInvokerInterceptor$1.run(ServiceInvokerInterceptor.java:58)
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at org.apache.cxf.workqueue.SynchronousExecutor.execute(SynchronousExecutor.java:37)
    at org.apache.cxf.interceptor.ServiceInvokerInterceptor.handleMessage(ServiceInvokerInterceptor.java:98)
    at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:236)
    at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:104) 

    Caused by: org.hibernate.LazyInitializationException: could not initialize proxy - no Session
        at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:167)
        at org.hibernate.proxy.AbstractLazyInitializer.getImplementation(AbstractLazyInitializer.java:215)
        at org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer.invoke(JavassistLazyInitializer.java:191)
        at ma.com.manager.movie.model.Movie$$_jvst1bf_21.getId(Movie$$_jvst1bf_21.java)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)...

as of exception - no sesion - meaning you have to do it session context (eg in @Transactional) — Antoniossss, May 10 '20 at 13:49
@Antoniossss Thank you for your reply, you mean @ Transactional in the Review Service class, when I'm calling my entities? — Angelika, May 10 '20 at 14:16
If that is the place that throws exception than yes it would fix it (but as it SHOULD be depends on broader scope as eg. maybe you simply ending your transaction to early etc.-but the cause is obvious) — Antoniossss, May 11 '20 at 07:47

score 0 · Accepted Answer · answered May 21 '20 at 20:44

0

I solved this issue by declaring both entities as fetch = FetchType.LAZY , and using hibernate initializer :

Movie mv = review.getRefMovie();
Hibernate.initialize(mv);

answered May 21 '20 at 20:44

Angelika

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Why EAGER takes time to get result and LAZY causes exception?

1 Answers1