Latest posts for the topic "eager fetching of entity associations using a jpql query"

eager fetching of entity associations using a jpql query

mankind1 — GMT

when I call the following query similar to the below: 'select a from Auction as a join fetch mycategory ' I receive the auction entity with an eagerly fetched 1:m or m:m association mycategory. on the second call of the query , the query is cached and the auction is returned with a null set for the association UNLESS within a transaction in which case the proxy is called . this ultimately causes a lazy initializationException since the code is passing around a detatched entity the only way around this is to set all associations as eager which is not a good idea. I have tried @Cache(usage = CacheConcurrencyStrategy.READ_WRITE,include="all") to include lazy and non lazy, however this doesnt fix the issue: below are the jars Im using. terracotta-toolkit-1.1-runtime-2.1.0.jar ehcache-core-2.3.2.jar ehcache-terracotta-2.3.2.jar Hibernate3.jar : 3.2.4 sp1 Hibernate-entitymanager.jar : 4.2.3.GA

Re:eager fetching of entity associations using a jpql query

ankur — GMT

Can you please send us your hibernate config files and the ehcache.xml?

Re:eager fetching of entity associations using a jpql query

mankind1 — GMT

****persistence.xml **************************

org.hibernate.ejb.HibernatePersistence

java:/autosalvageDS

************************************************* User entity with many-to-many relationship with groups @Entity @Table(name = "USERS") @Cache(usage = CacheConcurrencyStrategy.READ_WRITE,include="all") public class User implements Serializable { @Id @Column(name = "USER_ID", insertable = false, updatable = false, nullable = false) private Long id; @Column(name = "USER_NAME", insertable = false, updatable = false, nullable = false) private String username; @Column(name = "DIGESTED_PASSWORD", insertable = false, updatable = false) private String password; @Column(name = "CONTACT_POSTCODE", length = 15, insertable = false, updatable = false) protected String postcode; @Column(name = "CONTACT_EMAIL_ADDRESS1", length = 255, insertable = false, updatable = false) private String email; @Column(name = "NAME_FIRST", length = 255, insertable = false, updatable = false) private String firstName; @Column(name = "NAME_LAST", length = 255, insertable = false, updatable = false) private String lastName; @Column(name = "COMPANY_NAME ", length = 255, insertable = false, updatable = false) private String company; @ManyToMany() @JoinTable(name = "USER_GROUPS_LINK", joinColumns = @JoinColumn(name = "USER_ID", insertable = false, updatable = false), inverseJoinColumns = @JoinColumn(name = "GROUP_ID", insertable = false, updatable = false)) @Cache(usage= CacheConcurrencyStrategy.READ_WRITE,include="all",region="com.bluecycle.zephyr.auctions.domain.User.groups") private Set groups = new HashSet(); public User() { } public Long getId() { return id; } public String getUsername() { return username; } public String getPassword() { return password; } public String getEmail() { return email; } public String getFirstName() { return firstName; } public String getLastName() { return lastName; } public String getCompany() { return company; } public Set getGroups() { return groups; } public String getPostcode() { return postcode; } @Override public boolean equals(Object obj) { if (obj == null) { return false; } if (getClass() != obj.getClass()) { return false; } final User other = (User) obj; //noinspection RedundantIfStatement if ((this.username == null) ? (other.username != null) : !this.username.equals(other.username)) { return false; } return true; } @Override public int hashCode() { int hash = 5; hash = 29 * hash + (this.username != null ? this.username.hashCode() : 0); return hash; } @Override public String toString() { return new ToStringBuilder(this, StringStyle.STYLE).append("id", id).append("username", username).toString(); } }

eager fetching of entity associations using a jpql query

ankur — GMT

Can you please try "@ManyToMany(fetch = FetchType.EAGER)" for groups property?

Re:eager fetching of entity associations using a jpql query

mankind1 — GMT

yes, with eager fetching set on the association, there is no lazyinitializationException. however, I wish the entity assocations to be set as lazy and let the jpa query itself to determine whether to eagerly fetch or not (by the use of the 'join fetch groups' ) this has been working on the codebase before the 2nd level cache was introduced.

Re:eager fetching of entity associations using a jpql query

cdennis — GMT

I think the best suggestion is that you try running using Hibernate's built in Hashtable based second level cache (org.hibernate.cache.HashtableCacheProvider). If you still see the problem with this second level cache provider, then this is most likely either a bug in Hibernate or somewhere in your configuration or use of it. If everything works okay with the Hashtable provider then the next course of action would be try and create a test case so that we can reproduce this internally. Chris

Re:eager fetching of entity associations using a jpql query

mankind1 — GMT

thanks Chris, I'll try your suggestion out and let you know the outcome. I'll also create a simplified usecase that you can reproduce

Re:eager fetching of entity associations using a jpql query

rajoshi — GMT

Issue seems to be resolved.Please let us know if more information is required.