这是我在堆栈上的第一个问题,所以请保持温和:D
我正在尝试创建hibernate 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,现在它运行在VMware vFabric Server和MySQL DB上。
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;
类别:
@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:
由于@Thihara和@KarIP,我能够解决这个问题。我像这样覆盖了Team和League的toString():
@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DB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@XmlAccessorType(XmlAccessType.FIELD)
注释团队和联盟类,所以它不会看方法,而团队league
字段为@XmlTransient
,所以它不会被解析。
在这里,我甚至可以删除我的toString()实现,它仍然有效。我不完全确定为什么。问题解决了,但我希望听到更准确的解释。我不知道为什么JAXB停止数据获取,即使它是在整个数据库通信过程之后(或者不是?)。更具体地说,我正在使用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));
}
它可以抛出StackOverFlow的唯一方法是递归访问Team的联盟....
团队联盟到团队联盟
我猜测有一些功能试图将你的对象反射或递归转换为其他表示,从而导致无限循环。
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。我相信龙目岛生成的toString()
方法在我的Team
和League
对象之间引入了循环依赖。当我试图从我的Set<teams> teams
对象获取League
时,我得到了一个java.lang.StackOverflowError
,因为Spring正在调用toString方法进行日志记录。
我通过摆脱龙目岛的toString()
方法解决了这个问题。我用龙目岛的@Data
和@Getter
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toString()
方法。
如果使用toString()
复杂注释,循环依赖可以源自Lombok的@Data
自动生成方法。要排除某个字段的循环依赖性:
@Entity
@Data
public class Team {
...
@ToString.Exclude
@ManyToOne
private League league;
}
我有类似的问题,在我的情况下,这没有任何帮助。
帮助这一方法:
@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。
我没有在Product实体中放任何东西。
对我来说,Lombok提供的hashCode和toString默认实现都导致了这个问题。
您可以使用此批注来使用单个批注排除equalsAndHasCode的成员:
@EqualsAndHashCode(exclude = {"certificates", "payment"})
此外,如果您想从equals方法中仅排除成员,Lombok提供:@ToString.Exclude
@ToString.Exclude
@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "shipment")
private Set<Certificate> certificates;
我有这个错误,因为我正在解析使用jackson将@OneToMany
和@ManyToOne
两侧映射到json的对象列表导致无限循环。
如果你处于相同的情况,你可以通过使用@JsonManagedReference
和@JsonBackReference
注释来解决这个问题。
API的定义:
例:
owner.Java:
@JsonManagedReference
@OneToMany(mappedBy = "owner", fetch = FetchType.EAGER)
Set<Car> cars;
car.Java:
@JsonBackReference
@ManyToOne(fetch = FetchType.EAGER)
@JoinColumn(name = "owner_id")
private Owner owner;
另一种解决方案是使用@JsonIgnore
,它只是将字段设置为null。