将redis用作spring缓存，从redis获取对象时例外。 json数据保存到redis如下
{“ @ class”：“ cc.giveme5.auth.RoleEntity”，“ id”：10001，“ name”：“ member”，“ description”：“注册用户”，“ type”：1，“权限“：[” org.hibernate.collection.internal.PersistentSet“，[{” @ class“：” cc.giveme5.auth.PermissionEntity“，” id“：10001，” name“：” member：read“，” description “：”注册用户访问许可“}]]}
## env
spring-boot: 2.0.2.RELEASE
spring-data-redis: 2.0.7.RELEASE
jackson: 2.9.5
hibernate: 5.0.1
默认情况下，Spring Boot注册OpenEntityManagerInViewInterceptor以在spring-boot（2.0.2.RELEAS）中应用“在视图中打开EntityManager”模式。
@Entity
@Table(name = "t_auth_role_m")
@JsonIgnoreProperties(ignoreUnknown = true)
public class RoleEntity implements Serializable
{
@Id
@TableGenerator(name = "UrRole_gen", table = "t_com_id_generator_r", pkColumnName = "seq_name", pkColumnValue = "UrRole_id", valueColumnName = "seq_value", allocationSize = Constants.SQE_ALLOCATION)
@GeneratedValue(strategy = GenerationType.TABLE, generator = "UrRole_gen")
private Long id;
private String name;
private String description;
/**
* 角色对应许可
*/
@ManyToMany(fetch = FetchType.EAGER)
@JoinTable(name = "t_auth_role_perm_r",
joinColumns = { @JoinColumn(name = "role_id", referencedColumnName = "id") },
inverseJoinColumns = { @JoinColumn(name = "perm_id", referencedColumnName = "id") })
private Set<PermissionEntity> permissions;
}
@Entity
@Table(name = "t_auth_perm_m")
@JsonIgnoreProperties(ignoreUnknown=true)
public class PermissionEntity implements Serializable {
@Id
private Long id;
@Column(length = 32, name = "perm_name", nullable = false)
@Size(max = 32)
private String name;
@Column(length = 128, name = "perm_description", nullable = false)
@Size(max = 128)
private String description;
}
@Configuration
@EnableCaching
public class CacheConfiguration {
@Autowired
private RedisConnectionFactory redisConnectionFactory;
@Bean
@ConfigurationProperties(prefix = "giveme5.cache")
public Properties4Cache cacheProperties(){
return new Properties4Cache();
}
@Bean
@Primary
public CompositeCacheManager cacheManager(){
CompositeCacheManager cacheManager = new CompositeCacheManager();
ArrayList<CacheManager> cacheManagers = new ArrayList<>();
//cacheManagers.add(simpleCacheManager());
cacheManagers.add(redisCacheManager(new redisObjectMapper(), redisConnectionFactory));
cacheManager.setCacheManagers(cacheManagers);
cacheManager.setFallbackToNoOpCache(true);
return cacheManager;
}
@Bean
public RedisCacheManager redisCacheManager(ObjectMapper objectMapper, RedisConnectionFactory redisConnectionFactory) {
RedisCacheConfiguration cacheConfiguration = RedisCacheConfiguration.defaultCacheConfig()
.entryTtl(Duration.ofSeconds(cacheProperties().getRedisCacheTtl()))
.computePrefixWith(cacheName -> cacheProperties().getName().concat(":").concat(cacheName).concat(":"))
.serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(new StringRedisSerializer()))
.serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(new GenericJackson2JsonRedisSerializer(objectMapper)))
;
RedisCacheManager cacheManager = RedisCacheManager.builder(redisConnectionFactory)
.cacheDefaults(cacheConfiguration)
.build();
cacheManager.setTransactionAware(true);
return cacheManager;
}
public class redisObjectMapper extends ObjectMapper {
public redisObjectMapper() {
super();
// 将类型序列化到属性json字符串中
this.enableDefaultTyping(DefaultTyping.NON_FINAL, JsonTypeInfo.As.PROPERTY);
this.registerModule(new Hibernate5Module().disable(Hibernate5Module.Feature.USE_TRANSIENT_ANNOTATION));
// 对于找不到匹配属性的时候忽略报错
this.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
// 不包含任何属性的bean也不报错
this.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);
}
}
}
@Service
@Transactional
public class RoleService {
@Autowired
private IRoleRepository roleRepository;
@Cacheable(cacheNames = "default", key = "'role.' + #p0")
public RoleEntity role(Long roleId) {
return roleRepository.getOne(roleId);
}
}
public interface IRoleRepository extends BaseRepository<RoleEntity, Long, BaseVO> {
}
服务中发生错误：
org.springframework.data.redis.serializer.SerializationException: Could not read JSON: failed to lazily initialize a collection, could not initialize proxy - no Session (through reference chain: cc.giveme5.auth.RoleEntity["permissions"]); nested exception is com.fasterxml.jackson.databind.JsonMappingException: failed to lazily initialize a collection, could not initialize proxy - no Session (through reference chain: cc.giveme5.auth.RoleEntity["permissions"])
at org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer.deserialize(GenericJackson2JsonRedisSerializer.java:132) ~[spring-data-redis-2.0.7.RELEASE.jar:2.0.7.RELEASE]
at org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer.deserialize(GenericJackson2JsonRedisSerializer.java:110) ~[spring-data-redis-2.0.7.RELEASE.jar:2.0.7.RELEASE]
at org.springframework.data.redis.serializer.DefaultRedisElementReader.read(DefaultRedisElementReader.java:50) ~[spring-data-redis-2.0.7.RELEASE.jar:2.0.7.RELEASE]
at org.springframework.data.redis.serializer.RedisSerializationContext$SerializationPair.read(RedisSerializationContext.java:204)
...
Caused by: com.fasterxml.jackson.databind.JsonMappingException: failed to lazily initialize a collection, could not initialize proxy - no Session (through reference chain: cc.giveme5.auth.RoleEntity["permissions"])
at com.fasterxml.jackson.databind.JsonMappingException.wrapWithPath(JsonMappingException.java:391) ~[jackson-databind-2.9.5.jar:2.9.5]
at com.fasterxml.jackson.databind.JsonMappingException.wrapWithPath(JsonMappingException.java:351) ~[jackson-databind-2.9.5.jar:2.9.5]
at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.wrapAndThrow(BeanDeserializerBase.java:1704) ~[jackson-databind-2.9.5.jar:2.9.5]
at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:290) ~[jackson-databind-2.9.5.jar:2.9.5]
at com.fasterxml.jackson.databind.deser.BeanDeserializer._deserializeOther(BeanDeserializer.java:189) ~[jackson-databind-2.9.5.jar:2.9.5]
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:161) ~[jackson-databind-2.9.5.jar:2.9.5]
at com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer._deserializeTypedForId(AsPropertyTypeDeserializer.java:130) ~[jackson-databind-2.9.5.jar:2.9.5]
at com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer.deserializeTypedFromObject(AsPropertyTypeDeserializer.java:97) ~[jackson-databind-2.9.5.jar:2.9.5]
at com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer.deserializeTypedFromAny(AsPropertyTypeDeserializer.java:193) ~[jackson-databind-2.9.5.jar:2.9.5]
at com.fasterxml.jackson.databind.deser.std.UntypedObjectDeserializer$Vanilla.deserializeWithType(UntypedObjectDeserializer.java:712) ~[jackson-databind-2.9.5.jar:2.9.5]
at com.fasterxml.jackson.databind.deser.impl.TypeWrappedDeserializer.deserialize(TypeWrappedDeserializer.java:68) ~[jackson-databind-2.9.5.jar:2.9.5]
at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4001) ~[jackson-databind-2.9.5.jar:2.9.5]
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3079) ~[jackson-databind-2.9.5.jar:2.9.5]
at org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer.deserialize(GenericJackson2JsonRedisSerializer.java:130) ~[spring-data-redis-2.0.7.RELEASE.jar:2.0.7.RELEASE]
... 96 common frames omitted
Caused by: org.hibernate.LazyInitializationException: failed to lazily initialize a collection, could not initialize proxy - no Session
at org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:582) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
at org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:201) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
at org.hibernate.collection.internal.AbstractPersistentCollection.readSize(AbstractPersistentCollection.java:145) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
at org.hibernate.collection.internal.PersistentSet.size(PersistentSet.java:143) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:302) ~[jackson-databind-2.9.5.jar:2.9.5]
at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:245) ~[jackson-databind-2.9.5.jar:2.9.5]
at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:27) ~[jackson-databind-2.9.5.jar:2.9.5]
at com.fasterxml.jackson.databind.jsontype.impl.AsArrayTypeDeserializer._deserialize(AsArrayTypeDeserializer.java:116) ~[jackson-databind-2.9.5.jar:2.9.5]
at com.fasterxml.jackson.databind.jsontype.impl.AsArrayTypeDeserializer.deserializeTypedFromArray(AsArrayTypeDeserializer.java:53) ~[jackson-databind-2.9.5.jar:2.9.5]
at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserializeWithType(CollectionDeserializer.java:314) ~[jackson-databind-2.9.5.jar:2.9.5]
at com.fasterxml.jackson.databind.deser.impl.MethodProperty.deserializeAndSet(MethodProperty.java:129) ~[jackson-databind-2.9.5.jar:2.9.5]
at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:288) ~[jackson-databind-2.9.5.jar:2.9.5]
... 106 common frames omitted
答案 0 :(得分：0)
嗨。 调用时，Hibernate会初始化惰性属性，因此权限不会在加载 RoleEntity 中进行初始化。 通过休眠加载根对象后，首次调用权限时，休眠将从数据库中获取数据并加载权限属性。 为了启动惰性属性，休眠需要有效的会话。如果休眠会话已关闭，则对象将分离并且无法初始化lazy属性并引发 LazyInitializationException 为了解决您可以使用： 1-设置获取类型 join 。在一个select语句中使用根对象加载该属性。 2-在关闭会话之前，请调用权限属性进行初始化。 3-实现一种从 RoleEntity 对象中加载权限属性的方法。
这有用吗？
A.Ayati