关联实体共用@GenericGenerator引发StackOverflowError的解决咨询

DevOps 小满

2026-8-12

问题描述

我有两个Java实体类：

Class1 代码

@Entity
@Table(catalog = "mydb", schema = "dbo", name = "[myTable1]")
@Getter
@Setter
@Builder
@ToString(onlyExplicitlyIncluded = true)
@AllArgsConstructor
@NoArgsConstructor
public class Class1 {

    @Id
    @Column(name = "ID")
    @GeneratedValue(generator = "myGen")
    @GenericGenerator(name = "myGen",
            strategy = "Y.X.z.generator.MyGen")
    private Long id;

    @Column(name = "TEXT")
    private String text;

    @ManyToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "ID")
    private Class2 class2;
}

Class2 代码

@Entity
@Table(catalog = "mydb", schema = "dbo", name = "[myTable2]")
@Getter
@Setter
@Builder
@ToString(onlyExplicitlyIncluded = true)
@AllArgsConstructor
@NoArgsConstructor
public class Class2 {

    @Id
    @Column(name = "ID")
    @GeneratedValue(generator = "myGen")
    @GenericGenerator(name = "myGen",
            strategy = "de.svg.releasenotes.generator.MyGen")
    private Long id;

    @Column(name = "TEXT")
    private String text;
}

Class1与Class2是ManyToOne关联关系，两个类都使用同一个自定义GenericGenerator（Y.X.z.generator.MyGen），生成器代码如下：

MyGen 代码

import org.hibernate.HibernateException;
import org.hibernate.engine.spi.SharedSessionContractImplementor;
import org.hibernate.id.IdentifierGenerator;

import java.io.Serializable;
import java.util.stream.Stream;

public class MyGen implements IdentifierGenerator {

    @Override
    public Serializable generate(
            SharedSessionContractImplementor session, Object obj)
            throws HibernateException {

        String query = String.format("select %s from %s",
                session.getEntityPersister(obj.getClass().getName(), obj)
                        .getIdentifierPropertyName(),
                obj.getClass().getSimpleName());

        Stream<Long> ids = session.createQuery(query).stream();

        Long max = ids.max(Long::compare).orElse(0L);

        return max + 1;
    }
}

该生成器通过查询对应表的最大ID并加1生成新ID。调用POST接口时出现StackOverflowError，错误日志如下：

错误日志

2022-11-15 15:27:26.214 ERROR 276510 --- [io-13778-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Handler dispatch failed; nested exception is java.lang.StackOverflowError] with root cause

java.lang.StackOverflowError: null
    at org.apache.logging.slf4j.SLF4JLogger.isEnabledFor(SLF4JLogger.java:213) ~[log4j-to-slf4j-2.17.2.jar:2.17.2]
    at org.apache.logging.slf4j.SLF4JLogger.isEnabled(SLF4JLogger.java:121) ~[log4j-to-slf4j-2.17.2.jar:2.17.2]
    at org.apache.logging.log4j.spi.AbstractLogger.isEnabled(AbstractLogger.java:1513) ~[log4j-api-2.17.2.jar:2.17.2]
    at org.jboss.logging.Log4j2Logger.isEnabled(Log4j2Logger.java:46) ~[jboss-logging-3.4.3.Final.jar:3.4.3.Final]
    at org.jboss.logging.Logger.isTraceEnabled(Logger.java:98) ~[jboss-logging-3.4.3.Final.jar:3.4.3.Final]
    at org.jboss.logging.DelegatingBasicLogger.isTraceEnabled(DelegatingBasicLogger.java:54) ~[jboss-logging-3.4.3.Final.jar:3.4.3.Final]
    at org.hibernate.engine.internal.Cascade.cascade(Cascade.java:86) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.event.internal.AbstractFlushingEventListener.cascadeOnFlush(AbstractFlushingEventListener.java:159) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.event.internal.AbstractFlushingEventListener.prepareEntityFlushes(AbstractFlushingEventListener.java:149) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.event.internal.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:82) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.event.internal.DefaultAutoFlushEventListener.onAutoFlush(DefaultAutoFlushEventListener.java:50) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.event.service.internal.EventListenerGroupImpl.fireEventOnEachListener(EventListenerGroupImpl.java:107) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.internal.SessionImpl.autoFlushIfRequired(SessionImpl.java:1372) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1452) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.query.internal.AbstractProducedQuery.doList(AbstractProducedQuery.java:1649) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.query.internal.AbstractProducedQuery.list(AbstractProducedQuery.java:1617) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at  Y.X.z.generator.MyGen.generate(MyGen.java:25) ~[classes/:na]
    at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:115) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.event.internal.DefaultPersistEventListener.entityIsTransient(DefaultPersistEventListener.java:185) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:128) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.event.service.internal.EventListenerGroupImpl.fireEventOnEachListener(EventListenerGroupImpl.java:118) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.internal.SessionImpl.persistOnFlush(SessionImpl.java:801) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.engine.spi.CascadingActions$8.cascade(CascadingActions.java:341) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.engine.internal.Cascade.cascadeToOne(Cascade.java:510) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.engine.internal.Cascade.cascadeAssociation(Cascade.java:434) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.engine.internal.Cascade.cascadeProperty(Cascade.java:220) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.engine.internal.Cascade.cascade(Cascade.java:153) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.event.internal.AbstractFlushingEventListener.cascadeOnFlush(AbstractFlushingEventListener.java:159) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.event.internal.AbstractFlushingEventListener.prepareEntityFlushes(AbstractFlushingEventListener.java:149) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.event.internal.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:82) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.event.internal.DefaultAutoFlushEventListener.onAutoFlush(DefaultAutoFlushEventListener.java:50) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.event.service.internal.EventListenerGroupImpl.fireEventOnEachListener(EventListenerGroupImpl.java:107) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.internal.SessionImpl.autoFlushIfRequired(SessionImpl.java:1372) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1452) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.query.internal.AbstractProducedQuery.doList(AbstractProducedQuery.java:1649) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at org.hibernate.query.internal.AbstractProducedQuery.list(AbstractProducedQuery.java:1617) ~[hibernate-core-5.6.12.Final.jar:5.6.12.Final]
    at  Y.X.z.generator.MyGen.generate(MyGen.java:25) ~[classes/:na]
    ...

请问有什么解决办法？

问题分析

出现StackOverflowError的核心原因是无限循环的级联操作与ID生成逻辑冲突：

保存Class1时，@ManyToOne的CascadeType.ALL会触发Hibernate自动级联保存关联的Class2实例。
Class2生成ID时执行HQL查询，Hibernate为保证查询结果一致性，会自动flush会话中的未提交操作。
flush操作再次触发Class2的级联保存，进而再次调用MyGen生成ID、执行查询、触发flush，形成无限循环直至栈溢出。

另外，Class1中@JoinColumn(name = "ID")存在逻辑错误：外键与主键使用同一字段，会导致主键被外键覆盖，加剧关联逻辑混乱。

解决办法

1. 修正关联字段的外键配置

将Class1中的@JoinColumn改为正确的外键字段，避免主键与外键冲突：

@ManyToOne(cascade = CascadeType.ALL)
@JoinColumn(name = "CLASS2_ID") // 替换原有的"ID"
private Class2 class2;

2. 调整级联类型

避免使用CascadeType.ALL，根据业务需求选择合适的级联策略：

若无需级联保存Class2，移除cascade属性或设置为CascadeType.MERGE/CascadeType.REFRESH：

@ManyToOne(cascade = {CascadeType.MERGE, CascadeType.REFRESH})
@JoinColumn(name = "CLASS2_ID")
private Class2 class2;

若必须级联保存，提前手动保存Class2再关联到Class1，避免Hibernate自动触发级联：

// 先保存Class2
class2Repository.save(class2);
// 关联后保存Class1
class1.setClass2(class2);
class1Repository.save(class1);

3. 修改ID生成器，避免自动flush

在生成ID的查询中关闭自动flush，或改用原生SQL查询，防止触发会话刷新：

方案A：关闭HQL查询的自动flush

@Override
public Serializable generate(
        SharedSessionContractImplementor session, Object obj)
        throws HibernateException {

    String idProperty = session.getEntityPersister(obj.getClass().getName(), obj)
            .getIdentifierPropertyName();
    String queryStr = String.format("select %s from %s", idProperty, obj.getClass().getSimpleName());

    // 设置FlushMode为MANUAL，避免自动flush
    Stream<Long> ids = session.createQuery(queryStr)
            .setFlushMode(FlushMode.MANUAL)
            .stream();

    Long max = ids.max(Long::compare).orElse(0L);
    return max + 1;
}

方案B：使用原生SQL查询

原生SQL查询不会触发Hibernate的自动flush逻辑：

@Override
public Serializable generate(
        SharedSessionContractImplementor session, Object obj)
        throws HibernateException {

    String tableName = session.getEntityPersister(obj.getClass().getName(), obj)
            .getTableName();
    String idColumn = session.getEntityPersister(obj.getClass().getName(), obj)
            .getIdentifierColumnNames()[0];

    // 原生SQL查询最大ID
    String queryStr = String.format("select max(%s) from %s", idColumn, tableName);
    Long max = session.createNativeQuery(queryStr, Long.class)
            .uniqueResult();

    return (max == null ? 0L : max) + 1;
}

内容的提问来源于stack exchange，提问作者Abdessamad Abba

关联实体共用@GenericGenerator引发StackOverflowError的解决咨询

Class1 代码 #

Class2 代码 #

MyGen 代码 #

错误日志 #

1. 修正关联字段的外键配置 #

2. 调整级联类型 #

3. 修改ID生成器，避免自动flush #

方案A：关闭HQL查询的自动flush #

方案B：使用原生SQL查询 #