在Spring应用程序中,有时我会遇到异常:org.hibernate.LazyInitializationException:未能延迟初始化角色集合...无法初始化代理-在
。我无法测试 client.getCatIdSet<上没有 session
/fetch = FetchType.EAGER
是否修复问题,因为此错误并不经常发生。类有 Transactional
注解,方法是公共(public)的。我该如何解决这个异常?
@Service
@Transactional
public class ChatService {
@PersistenceContext
EntityManager entityManager;
public BotRequest getBotRequest(MessageData messageData) {
Client client = messageData.getMessage().getClient();
Optional<CatId> mbCatId = Optional.ofNullable(client.getCatIdSet())
.orElse(Collections.emptySet())
.filter
...
此方法调用自:
@Service
public class SendMsgToCatBotService extends SendMsgToBotService {
@Override
protected BotRequest createBotRequest(MessageData messageData) {
return chatService.getBotRequest(messageData);
}
客户端实体:
@Entity
@Table(name = "clients")
public class Client implements Serializable {
private int id;
private Set<CatId> catIdSet;
@Id
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "clients_generation")
@SequenceGenerator(name = "clients_generation", sequenceName = "clients_id_seq", allocationSize = 1)
@Column(name = "id")
public int getId() {
return id;
}
@OneToMany(mappedBy = "client")
public Set<CatId> getCatIdSet() {
return catIdSet;
}
最佳答案
在您的 web.xml 中,添加以下过滤器。
<filter>
<filter-name>SpringOpenEntityManagerInViewFilter</filter-name>
<filter-class>org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>SpringOpenEntityManagerInViewFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
关于java - 如何修复 LazyInitializationException - Spring 应用程序中没有 session ?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/55882857/