Hibernate OneToMany java.lang.StackOverFlowError

Question

E 'la mia prima domanda qui sulla pila, quindi si prega di essere gentile: D

Sto cercando di creare letargo OneToMany rapporto. Quando provo a recuperare alcuni dati dal mio DB, sto ricevendo StackOverflowError. Ma quando rimuovo OneToMany part, tutto procede normalmente. Questo fa parte del mio servizio REST, per ora funziona su VMware vFabric Server e MySQL DB.

Fetch esempio:

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

script di MySQL:

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; 

Classi:

@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; 
} 

Errore:

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:

sono stato in grado di risolvere questo fuori grazie a @Thihara e @KarIP. Ho sovrascritto toString() per il Team e la Lega in questo modo:

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

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

ed è stato in grado di recuperare i dati da DB come voleva. Ma poi durante l'analisi ho ottenuto l'errore JAXB con cicli infiniti. Quindi ho annotato la classe Team e League con @XmlAccessorType(XmlAccessType.FIELD), quindi non esaminerà i metodi e il campo Team come @XmlTransient, quindi non verrà analizzato.

Qui posso anche rimuovere le implementazioni toString() e funziona ancora. Non sono completamente sicuro del perché. Il problema è risolto, ma mi piacerebbe sentire una spiegazione più precisa. Non so perché JAXB ha interrotto il recupero dei dati, anche se è dopo l'intero processo di comunicazione del DB (o non lo è?). Per essere più precisi, sto usando Jersey per questo:

@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

L'unico modo in cui può gettare una StackOverflow è quando League della tua squadra si accede in modo ricorsivo ....

squadra di Lega Team alla Lega

Suppongo che ci sia qualche funzione che prova a convertire i tuoi oggetti in qualche altra rappresentazione in modo riflessivo o ricorsivo dando come risultato un ciclo infinito.

Answer 2

Ho avuto un problema molto simile. Stavo usando l'annotazione @Data di Lombok sugli oggetti del mio modello per generare automaticamente getter, setter e altri metodi standard. Credo che il metodo toString() generato da Lombok abbia introdotto una dipendenza circolare tra i miei oggetti Team e League. Quando ho cercato di ottenere il Set<teams> teams dal mio oggetto League, ho ottenuto un java.lang.StackOverflowError perché Spring stava chiamando il metodo toString per scopi di registrazione (credo).

Ho risolto risolto questo problema eliminando il metodo toString() di Lombok. Ho sostituito l'annotazione @Data con le annotazioni di Lombok @Getter e @Setter. In questo modo potrei comunque beneficiare dei getter e setter liberi senza ottenere il metodo toString().