71

这是我在堆栈上的第一个问题，所以请温柔：D

我正在尝试创建休眠的 OneToMany 关系。当我尝试从我的数据库中获取一些数据时，我得到了 StackOverflowError。但是当我删除 OneToMany 部分时，一切正常。这是我的 REST 服务的一部分，目前它在 VMware vFabric Server 和 MySQL DB 上运行。

获取示例： 

@Inject
private EntityManager entityManager;
...
entityManager.find(League.class, 1);
...
entityManager.find(Team.class, 1);

MySQL脚本： 

CREATE TABLE league (
    id int(11) NOT NULL AUTO_INCREMENT,
    name varchar(20) COLLATE utf8_unicode_ci NOT NULL,
    PRIMARY KEY (id)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

CREATE TABLE team (
    team_id int(11) NOT NULL AUTO_INCREMENT,
    name varchar(20) COLLATE utf8_unicode_ci NOT NULL,
    fk_leagueId int(11) NOT NULL,
    PRIMARY KEY (team_id),
    FOREIGN KEY (fk_leagueId) REFERENCES league(id)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

课程： 

@XmlRootElement
@Entity
@Table(name = "team")
@Data
public class Team {
    @Id
    @GeneratedValue(generator = "increment")
    @GenericGenerator(name = "increment", strategy = "increment")
    @Column(name = "team_id")
    private int id;
    @Column(name = "name")
    private String name;
    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "fk_leagueId", nullable = false)
    private League league;
}

@XmlRootElement
@Entity
@Table(name = "league")
@Data
public class League {
    @Id
    @GeneratedValue(generator = "increment")
    @GenericGenerator(name = "increment", strategy = "increment")
    @Column(name = "id")
    private int id;
    @Column(name = "name")
    private String name;
    //if I comment 2 lines below, there is no error, and everything works fine
    @OneToMany(fetch = FetchType.LAZY, mappedBy = "league")
    private Set<span><</span>Team> teams;
}

错误：

Hibernate: select league0_.id as id1_1_0_, league0_.name as name2_1_0_ from league league0_ where league0_.id=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Hibernate: select teams0_.fk_leagueId as fk3_1_1_, teams0_.team_id as team1_4_1_, teams0_.team_id as team1_4_0_, teams0_.fk_leagueId as fk3_4_0_, teams0_.name as name2_4_0_ from team teams0_ where teams0_.fk_leagueId=?
Exception in thread "tomcat-http--3" java.lang.StackOverflowError
    at org.jboss.logging.JDKLogger.translate(JDKLogger.java:73)
    at org.jboss.logging.JDKLogger.isEnabled(JDKLogger.java:85)
    at org.jboss.logging.JDKLogger.doLog(JDKLogger.java:41)
    at org.jboss.logging.Logger.debug(Logger.java:406)
    at org.hibernate.internal.CoreMessageLogger_$logger.debug(CoreMessageLogger_$logger.java:525)
    at org.hibernate.engine.jdbc.spi.SqlStatementLogger.logStatement(SqlStatementLogger.java:104)
    at org.hibernate.engine.jdbc.spi.SqlStatementLogger.logStatement(SqlStatementLogger.java:95)
    at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:180)
    at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.prepareQueryStatement(StatementPreparerImpl.java:159)
    at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1858)
    at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1835)
    at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1815)
    at org.hibernate.loader.Loader.doQuery(Loader.java:899)
    at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:341)
    at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:311)
    at org.hibernate.loader.Loader.loadCollection(Loader.java:2234)
    at org.hibernate.loader.collection.CollectionLoader.initialize(CollectionLoader.java:65)
    at org.hibernate.persister.collection.AbstractCollectionPersister.initialize(AbstractCollectionPersister.java:674)
    at org.hibernate.event.internal.DefaultInitializeCollectionEventListener.onInitializeCollection(DefaultInitializeCollectionEventListener.java:83)
    at org.hibernate.internal.SessionImpl.initializeCollection(SessionImpl.java:1849)
    at org.hibernate.collection.internal.AbstractPersistentCollection$4.doWork(AbstractPersistentCollection.java:549)
    at org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:234)
    at org.hibernate.collection.internal.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:545)
    at org.hibernate.collection.internal.AbstractPersistentCollection.read(AbstractPersistentCollection.java:124)
    at org.hibernate.collection.internal.PersistentSet.hashCode(PersistentSet.java:428)
    at com.lukaszb.motspe.webapp.model.League.hashCode(League.java:21)
    at com.lukaszb.motspe.webapp.model.Team.hashCode(Team.java:20)
    at java.util.HashMap.hash(HashMap.java:351)
    at java.util.HashMap.put(HashMap.java:471)
    at java.util.HashSet.add(HashSet.java:217)
...

编辑：

感谢@Thihara 和@KarIP，我能够解决这个问题。我已经为 Team 和 League 覆盖了 toString()，如下所示：

@Override
public String toString() {
    return "League [id=" + id + ", name=" + name + "]";
}

@Override
public String toString() {
    return "Team [id=" + id + ", name=" + name + "]";
}

并且能够根据需要从数据库中获取数据。但是在解析时，我得到了无限循环的 JAXB 错误。所以我用 注释了 Team 和 League 类@XmlAccessorType(XmlAccessType.FIELD)，所以它不会查看方法，并且 Teamleague字段为@XmlTransient，所以它不会被解析。

在这里，我什至可以删除我的 toString() 实现，它仍然有效。我不完全确定为什么。问题已解决，但我想听听更准确的解释。我不知道为什么 JAXB 停止数据获取，即使它是在整个 DB 通信过程之后（或者不是？）。更具体地说，我为此使用 Jersey：

@GET
@Path("search/id")
@Produces({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })
public List<League> searchById(@QueryParam("id") int id) {
return Arrays.asList(leagueDAO.getById(id));
}
4

14 回答 14

116

我有一个非常相似的问题。我在我的模型对象上使用 Lombok 的@Data注释来自动生成 getter、setter 和其他标准方法。我相信 Lombok 生成的方法在 my和objectstoString()之间引入了循环依赖。当我试图从我的对象中获取时，我得到了一个，因为 Spring 正在调用 toString 方法进行日志记录。 TeamLeagueSet<teams> teamsLeaguejava.lang.StackOverflowError

我通过摆脱 Lombok 的toString()方法解决了这个问题。我@Data用 Lombok@Getter和注释替换了@Setter注释。这样，我仍然可以从免费的 getter 和 setter 中受益，而无需获得该toString()方法。

于 2016-12-15T15:34:24.733 回答
36

它可以抛出 StackOverFlow 的唯一方法是递归访问您的 Team's League....

团队到联赛 团队到联赛

我猜有一些函数试图将你的对象反射或递归地转换为其他表示，从而导致无限循环。

于 2013-07-03T10:36:22.820 回答
31

如果您使用复杂的注解，循环依赖可以源自Lombok 的自动生成方法。 要排除您对某个字段的循环依赖：toString()@Data

@Entity
@Data
public class Team {

  ...

  @ToString.Exclude
  @ManyToOne
  private League league;
}
于 2019-02-11T15:07:27.443 回答
19

我遇到了这个错误，因为我正在解析一个映射在两边的对象列表，@OneToMany并@ManyToOne使用杰克逊解析到 json，这导致了无限循环。

如果你处于同样的情况，你可以通过使用@JsonManagedReference和@JsonBackReference注释来解决这个问题。

来自 API 的定义：

例子：

所有者.java：

@JsonManagedReference
@OneToMany(mappedBy = "owner", fetch = FetchType.EAGER)
Set<Car> cars;

汽车.java：

@JsonBackReference
@ManyToOne(fetch = FetchType.EAGER)
@JoinColumn(name = "owner_id")
private Owner owner;

另一种解决方案是使用@JsonIgnore它只会将 null 设置为该字段。

于 2019-06-06T12:04:21.987 回答
9

对我来说，Lombok 提供的 hashCode 和 toString 默认实现都导致了这个问题。

您可以使用此注解排除具有单个注解的 equalsAndHasCode 的成员：

@EqualsAndHashCode(exclude = {"certificates", "payment"})

此外，如果您只想从 equals 方法中排除成员，Lombok 提供：@ToString.Exclude

@ToString.Exclude
@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "shipment")
    private Set<Certificate> certificates;
于 2019-03-29T20:30:20.157 回答
7

我用 Lombok 的 @Getter 和 @Setter 注释替换了 @Data 注释

于 2020-01-28T11:07:42.537 回答
3

我有类似的问题，就我而言，这没有任何帮助。

帮助了这一方法：

@OneToMany(cascade = CascadeType.ALL)
@JoinColumn(name = "order_id")
@Fetch(value = FetchMode.SUBSELECT)
private List<Product> orderLines;

name = "order_id" 是 Product 表中的外键列。

而且我没有在产品实体中放任何东西。

于 2018-05-17T18:42:11.237 回答
3

我挣扎了很长时间，并认为这是 Kotlin 的问题，为什么它会抛出 Stackoverflow 异常。最后是Jackson，它被Spring Hibernate使用并导致Stackoverflow。

你可以通过设置@JsonIgnoreProperties两边来解决这个问题。例子：

public class ProductEntity implements Serializable {

private List<ProductPriceEntity> refProductPriceEntities = new ArrayList<>();

@OneToMany(
        mappedBy = "product",
        fetch = FetchType.LAZY,
        cascade = CascadeType.ALL,
        orphanRemoval = true,
        targetEntity = ProductPriceEntity.class)
  @JsonIgnoreProperties(value = "product", allowSetters = true)
  public List<ProductPriceEntity> getRefProductPriceEntities() {
    return refProductPriceEntities;
  }

  public void setRefProductPriceEntities(List<ProductPriceEntity> refProductPriceEntities) {
    this.refProductPriceEntities = refProductPriceEntities;
  }
}

最后是另一边，这导致了stackoverflow异常。

public class ProductPriceEntity {

private ProductEntity product;

@ManyToOne(fetch = FetchType.LAZY)
@JoinColumns({
        @JoinColumn(name = "product_id", referencedColumnName = "id", nullable = false),
        @JoinColumn(name = "product_version_id", referencedColumnName = "version_id", nullable = false)
})
@JsonIgnoreProperties(value = "refProductPriceEntities", allowSetters = true)
public ProductEntity getProduct() {
    return product;
}

public void setProduct(ProductEntity product) {
    this.product = product;
}
}
于 2020-08-15T14:55:07.180 回答
2

在休眠的 OneToOne 映射中出现此错误，实体类无法转换为字符串。

Class A(Details.class)-
@OneToOne
@JoinColumn(name="billing_address_id")
private Address billingAddress;

@OneToOne
@JoinColumn(name="shipping_address_id")
private Address shippingAddress;


Class B(Address.class)-
@OneToOne(mappedBy="billingAddress")
private Details billingDetails;

@OneToOne(mappedBy="shippingAddress")
private Details shippingDetails;

错误 - 因为 A 类正在调用 B 类，同样，B 类正在调用 A 类。需要删除两者之一。那么这个问题就会得到解决。

于 2021-04-27T07:39:54.687 回答
1

当我遇到这个问题时，我正在将实体转换为 dto。然后我意识到我正在从用manytoone注释的桥类中调用用onetomany注释的父类。因为父节点已经调用了桥，所以它变成了循环的并且集合递归了。我没有调用填充的父方法，而是初始化并填充了子中的父方法。

于 2020-05-19T03:34:04.293 回答
1

另请参阅：Hibernate 在查询时抛出 StackOverflowError

在我的例子中，我@IdClass在一个实体上使用了注释，该实体有一个外键作为其主键的一部分：

@IdClass(MyEntity.MyEntityKey.class)
public class MyEntity {
   public static class MyEntityKey {
       private Foo parent;
       private int count;
       // Getters, setters, constructor, ...
   }

   @Id
   private Foo parent;
   @Id
   private int number;
  
   //...
}

现在，当加载Foo并急切地加载所有s 时，Hibernate在构建导致堆栈溢出的键时MyEntity再次加载父实体。Foo

我通过使用显式键属性（即包括 Foo 的键MyEntityKey而不仅仅是对 的引用Foo）对 id 进行建模来解决问题，如Composite key handling 中所示，使用 Spring boot java 中的 @Idclass 注释（也适用于非 Spring Hibernate ）。简而言之：使用@JoinColumns注解来指定导航属性（到父级）和 id 列之间的关系。

于 2020-06-24T11:47:07.257 回答
1

当我遇到这个问题时，我可以用@JsonManagedReferenceand来解决它@JsonBackReference，但这意味着在反序列化为 json 时，只有实体的一侧有子元素。即在您的球队和联赛示例中，只有联赛会显示球队，而球队不会显示它属于哪个联赛。

要允许双方，@JsonIdentityInfo请在您的实体中使用注释并删除@JsonBackReferenceand @JsonManagedReference。您的实体将类似于：

@JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class, property = "id")
public class Team {
...

这用我正在寻找的东西替换了循环引用。

于 2021-05-20T03:20:30.173 回答
0

我发现使用 @EqualsAndHashCode(onlyExplicitlyIncluded = true) 是一个很好的起点。在大多数情况下，对象之间的相等应该只在特定值上完成。如果您对每个实体都使用它，它将迫使您选择实际想要包含在相等性中的内容，并且可能会阻止循环内存引用。

于 2021-05-03T21:06:29.833 回答
0

我在保存和刷新时使用 Lombok 时遇到了类似的问题。它在我的@EqualsAndHashCode 中，因此您可以按属性名称排除子集合：

@Data
@EqualsAndHashCode(callSuper = true, exclude = "childRowCollectionProp")
@Entity
@Table(name = "parent")
public class Parent extends BaseEntityWithId{
于 2021-12-28T18:33:31.970 回答