Overcoming lazy loading issues in Hibernate, many-to-many, relationship

Question

Teaching myself Hibernate, I have the following table structure/relationship Which is represented by the following classes... Users ``` @Entity @Table(name = "users") public class User implements IUser, Serializable { @Id @GeneratedValue(strategy = javax.persistence.GenerationType.IDENTITY) @SequenceGenerator(name = "user_key_seq") @Column(name = "key", insertable = false, updatable = false) private Long key; @Column(name = "name") private String name; @ManyToMany(cascade = {CascadeType.ALL}) @JoinTable(name = "userroles", joinColumns = { @JoinColumn(name = "userkey")}, inverseJoinColumns = { @JoinColumn(name = "rolekey")}) private Set roles = new HashSet<>(5); @Override public Set getRoles() { return roles; } // Other setters and getters } ``` Roles ``` @Entity @Table(name = "roles") public class Role implements IRole, Serializable { @Id @GeneratedValue(strategy = javax.persistence.GenerationType.IDENTITY) @SequenceGenerator(name = "roles_key_seq") @Column(name = "k…

Accepted Answer

If you want to load users with their roles, but still keep the association lazy, use a HQL query containing a `left join fetch`:

```
select u from User u left join fetch u.roles where ...
```

If you have a User and want to make sure its roles collection is initialized before closing the session, call `Hibernate.initialize(user.getRoles())`.

Overcoming lazy loading issues in Hibernate, many-to-many, relationship

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