Hibernate 错误：org.hibernate.LazyInitializationException: failed to lazily initial

有两张多对多关联表：

@Entity
@AccessType("field")
@Table(name="MENU")
public class Menu implements Serializable {
	private static final long serialVersionUID = 1L;

	@Id
	@Column(name="menu_id")
	private Long menuId;

	@Column(name="menu_Name")
	private String menuName;

	/** 
     * 角色-菜单关联 
     */  
	@ManyToMany(cascade = { CascadeType.PERSIST, CascadeType.MERGE }, fetch=FetchType.LAZY)//合并
	@JoinTable(name = "ROLE_MENU", joinColumns = { @JoinColumn(name = "menu_id") }, inverseJoinColumns = { @JoinColumn(name = "role_id") })
//    @PersistenceContext(type = PersistenceContextType.EXTENDED)
	private Set<Role> roles = new LinkedHashSet<Role>();

	public Set<Role> getRoles() {
		return roles;
	}
	public void setRoles(Set<Role> roles) {
		this.roles = roles;
	}
}

和

@Entity
@AccessType("field")
@Table(name="ROLE")
public class Role implements Serializable {
	private static final long serialVersionUID = 1L;

	@Id
	@Column(name="role_id")
	private Long roleId;

	@Column(name="role_Name")
	private String roleName;


	/** 
     * 角色-菜单关联  
     */  
    @ManyToMany(cascade={CascadeType.PERSIST, CascadeType.MERGE}, fetch=FetchType.LAZY)
	@JoinTable(name = "ROLE_MENU", joinColumns = { @JoinColumn(name = "role_id") }, inverseJoinColumns = { @JoinColumn(name = "menu_id") })  
    private Set<Menu> menus = new LinkedHashSet<Menu>();

	public Set<Menu> getMenus() {
		return menus;
	}
	public void setMenus(Set<Menu> menus) {
		this.menus = menus;
	}
}

注意：一定要两张表分别@JoinTable(name = "ROLE_MENU")

在Role在引用menus的时候，报：org.hibernate.LazyInitializationException: failed to lazily initial

解决办法：roleDao.getHibernateTemplate().initialize(role.getMenus());


当关联表中不存在此记录时，role.getMenus();将会报错：org.hibernate.ObjectNotFoundException: No row with the given identifier exists:

解决办法：加上 @NotFound(action = NotFoundAction.IGNORE)