Hibernate OneToMany java.lang.StackOverflowError

Question

It's my first question here on stack, so please be gentle :D

I'm trying to create hibernate OneToMany relationship. When I try to fetch some data from my DB, I'm getting StackOverflowError. But when i remove OneToMany part, everything goes normally. This is part of my REST Service, for now it runs on VMware vFabric Server and MySQL DB.

Fetch example:

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

MySQL script:

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; 

Classes:

@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; } 

Error:

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) ... 

Edit:

I was able to solve this out thanks to @Thihara and @KarIP. I have overriden toString() for Team and League like this:

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

and was able to fetch data from DB as wanted. But then while parsing I got JAXB error with infinite cycles. So i annotated Team and League class with @XmlAccessorType(XmlAccessType.FIELD), so it won't look at methods, and Team league field as @XmlTransient, so it won't be parsed.

Here I can even remove my toString() implementations, and it still works. I'm not completely sure why. Problem is solved, but I would like to hear more precise explanation. I don't know why JAXB stopped data fetch, even if it's after whole DB communication process(or isn't?). To be more specific, I'm using Jersey for that:

@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)); } 

Answer 1

I had a very similar issue. I was using Lombok's @Data annotation on my model objects to auto-generate getters, setters, and other standard methods. I believe the toString() method generated by Lombok introduced a circular dependency between my Team and League objects. When I tried to get the Set<teams> teams from my League object, I got a java.lang.StackOverflowError because Spring was calling the toString method for logging purposes.

I resolved this by getting rid of Lombok's toString() method. I replaced the @Data annotation with Lombok's @Getter and @Setter annotations. That way I still could benefit from free getters and setters without getting the toString() method.

Answer 2

The only way it can throw an StackOverFlow is when your Team's League is accessed recursively....

Team to League to Team to League

I'm guessing there's some function trying to convert your objects into some other representation reflectively or recursively resulting in an infinite loop.