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spring - 在 Spring Data JPA Entity 中获取集合，抛出堆栈溢出异常

问题描述

我想从一个实体中获取一个集合类型变量，并且该集合使用@OneToMany 进行注释。

public class Cheat {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "cheat_seq", length = 10)
    private Long cheatSeq;


    @OneToMany(mappedBy = "cheat", cascade=CascadeType.ALL, fetch=FetchType.LAZY)
    private Set<CheatVote> vote;
}

上述实体具有投票成员变量。我想得到它，但是当我调用cheat.getVote()时，它会抛出错误。

此外，CheatVote 实体看起来像：

public class CheatVote{

    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Id
    @Column(name="seq", nullable=false)
    private Long seq;

    @JoinColumn(name="cheat_fk", referencedColumnName="cheat_seq")
    @ManyToOne(fetch=FetchType.LAZY, cascade=CascadeType.ALL)
    @NonNull
    private Cheat cheat;
}

如前所述，我调用了 cheat.getVote();

    @Test
    public void test23123() throws Exception{
        cheatService.addCheat(addDTO1);
        Cheat cheat = cheatService.findAll().get(0);
        assertNull(cheat.getVote());

        cheatVoteService.addGoodVote(cheat.getCheatSeq(), "127.0.0.1");

        cheat = cheatService.findOne(cheat.getCheatSeq());
        //cheat.getVote();
    }

控制台中的部分错误堆栈如下：

2018-10-14 07:34:14.414  WARN 11852 --- [           main] o.h.e.loading.internal.LoadContexts      : HHH000100: Fail-safe cleanup (collections) : org.hibernate.engine.loading.internal.CollectionLoadContext@63a7af06<rs=HikariProxyResultSet@1779202806 wrapping com.mysql.jdbc.JDBC42ResultSet@2762253e>
2018-10-14 07:34:14.414  WARN 11852 --- [           main] o.h.e.loading.internal.LoadContexts      : HHH000100: Fail-safe cleanup (collections) : org.hibernate.engine.loading.internal.CollectionLoadContext@5f01fb5c<rs=HikariProxyResultSet@460107127 wrapping com.mysql.jdbc.JDBC42ResultSet@18ca9277>
2018-10-14 07:34:14.435  WARN 11852 --- [           main] o.h.e.loading.internal.LoadContexts      : HHH000100: Fail-safe cleanup (collections) : org.hibernate.engine.loading.internal.CollectionLoadContext@75c77add<rs=HikariProxyResultSet@209972599 wrapping com.mysql.jdbc.JDBC42ResultSet@21688427>
2018-10-14 07:34:14.436  WARN 11852 --- [           main] o.h.e.loading.internal.LoadContexts      : HHH000100: Fail-safe cleanup (collections) : org.hibernate.engine.loading.internal.CollectionLoadContext@d5e3f55<rs=HikariProxyResultSet@1786422901 wrapping com.mysql.jdbc.JDBC42ResultSet@2dd2ff87>
2018-10-14 07:34:14.436  WARN 11852 --- [           main] o.h.e.loading.internal.LoadContexts      : HHH000100: Fail-safe cleanup (collections) : org.hibernate.engine.loading.internal.CollectionLoadContext@53df7e67<rs=HikariProxyResultSet@1398327546 wrapping com.mysql.jdbc.JDBC42ResultSet@4a6ef712>
2018-10-14 07:34:14.436  WARN 11852 --- [           main] o.h.e.loading.internal.LoadContexts      : HHH000100: Fail-safe cleanup (collections) : org.hibernate.engine.loading.internal.CollectionLoadContext@3d4b45b<rs=HikariProxyResultSet@1198265211 wrapping com.mysql.jdbc.JDBC42ResultSet@56d5460f>
2018-10-14 07:34:14.436  WARN 11852 --- [           main] o.h.e.loading.internal.LoadContexts      : HHH000100: Fail-safe cleanup (collections) : org.hibernate.engine.loading.internal.CollectionLoadContext@4d0b276e<rs=HikariProxyResultSet@618095995 wrapping com.mysql.jdbc.JDBC42ResultSet@7614378d>
2018-10-14 07:34:14.436  WARN 11852 --- [           main] o.h.e.loading.internal.LoadContexts      : HHH000100: Fail-safe cleanup (collections) : org.hibernate.engine.loading.internal.CollectionLoadContext@31531d0d<rs=HikariProxyResultSet@96665725 wrapping com.mysql.jdbc.JDBC42ResultSet@303fbc4>
2018-10-14 07:34:14.436  WARN 11852 --- [           main] o.h.e.loading.internal.LoadContexts      : HHH000100: Fail-safe cleanup (collections) : org.hibernate.engine.loading.internal.CollectionLoadContext@19d76106<rs=HikariProxyResultSet@1722528506 wrapping com.mysql.jdbc.JDBC42ResultSet@25dad235>
2018-10-14 07:34:14.436  WARN 11852 --- [           main] o.h.e.loading.internal.LoadContexts      : HHH000100: Fail-safe cleanup (collections) : org.hibernate.engine.loading.internal.CollectionLoadContext@3f87780b<rs=HikariProxyResultSet@208438522 wrapping com.mysql.jdbc.JDBC42ResultSet@72168258>
2018-10-14 07:34:14.506  INFO 11852 --- [       Thread-3] o.s.w.c.s.GenericWebApplicationContext   : Closing org.springframework.web.context.support.GenericWebApplicationContext@5fb759d6: startup date [Sun Oct 14 07:33:53 KST 2018]; root of context hierarchy
2018-10-14 07:34:14.550  INFO 11852 --- [       Thread-3] j.LocalContainerEntityManagerFactoryBean : Closing JPA EntityManagerFactory for persistence unit 'default'
2018-10-14 07:34:14.554  INFO 11852 --- [       Thread-3] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Shutdown initiated...
2018-10-14 07:34:14.581  INFO 11852 --- [       Thread-3] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Shutdown completed.

JUnit 错误面板中的部分错误堆栈如下：

at org.hibernate.collection.internal.PersistentSet.hashCode(PersistentSet.java:430)
    at com.aibiigae1221.skyQuiz.data.entity.Cheat.hashCode(Cheat.java:30)
    at com.aibiigae1221.skyQuiz.data.entity.CheatVote.hashCode(CheatVote.java:21)
    at java.util.HashMap.hash(HashMap.java:338)
    at java.util.HashMap.put(HashMap.java:611)
    at java.util.HashSet.add(HashSet.java:219)
    at java.util.AbstractCollection.addAll(AbstractCollection.java:344)
    at org.hibernate.collection.internal.PersistentSet.endRead(PersistentSet.java:327)
    at org.hibernate.engine.loading.internal.CollectionLoadContext.endLoadingCollection(CollectionLoadContext.java:234)
    at org.hibernate.engine.loading.internal.CollectionLoadContext.endLoadingCollections(CollectionLoadContext.java:221)
    at org.hibernate.engine.loading.internal.CollectionLoadContext.endLoadingCollections(CollectionLoadContext.java:194)
    at org.hibernate.loader.plan.exec.process.internal.CollectionReferenceInitializerImpl.endLoading(CollectionReferenceInitializerImpl.java:154)
    at org.hibernate.loader.plan.exec.process.internal.AbstractRowReader.finishLoadingCollections(AbstractRowReader.java:249)
    at org.hibernate.loader.plan.exec.process.internal.AbstractRowReader.finishUp(AbstractRowReader.java:212)
    at org.hibernate.loader.plan.exec.process.internal.ResultSetProcessorImpl.extractResults(ResultSetProcessorImpl.java:133)
    at org.hibernate.loader.plan.exec.internal.AbstractLoadPlanBasedLoader.executeLoad(AbstractLoadPlanBasedLoader.java:122)
    at org.hibernate.loader.plan.exec.internal.AbstractLoadPlanBasedLoader.executeLoad(AbstractLoadPlanBasedLoader.java:86)
    at org.hibernate.loader.collection.plan.AbstractLoadPlanBasedCollectionInitializer.initialize(AbstractLoadPlanBasedCollectionInitializer.java:87)
    at org.hibernate.persister.collection.AbstractCollectionPersister.initialize(AbstractCollectionPersister.java:688)
    at org.hibernate.event.internal.DefaultInitializeCollectionEventListener.onInitializeCollection(DefaultInitializeCollectionEventListener.java:75)
    at org.hibernate.internal.SessionImpl.initializeCollection(SessionImpl.java:2223)
    at org.hibernate.collection.internal.AbstractPersistentCollection$4.doWork(AbstractPersistentCollection.java:565)
    at org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:247)
    at org.hibernate.collection.internal.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:561)
    at org.hibernate.collection.internal.AbstractPersistentCollection.read(AbstractPersistentCollection.java:132)

我的spring boot版本是2.0.5.RELEASE，Maven中的Spring data jpa版本（我没有手动配置）是2.0.10.RELEASE

什么地方出了错 ？？

标签： springjpa

解决方案

如果您想接收完全初始化的实体，则 Fetch 类型应该是 EAGER 而不是 LAZY。使用默认模式 ( LAZY ) Hibernate 不会费心初始化相关对象。

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