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[编辑：将 q 中的弹簧版本固定到 5.2.9。v2.3.4 是聚合的 Maven 开发。]

我已经通过大量帖子试图弄清楚这一点。似乎存在一个巨大的兼容性问题，但我无法弄清楚要更改为哪些版本。我通常不做Java，但在教学时必须这样做，所以希望有人会忽略我不存在的Java技能并给我一些建议。‍♂️</p>

如果我单步执行反汇编代码，我可以看到我的单元测试（集成）在尝试反映我的 ID 属性时会做其他事情，而不是使用 Spring 运行时所做的事情。

[编辑] 这是 SQL 日志：

Hibernate: create table ChatMessages (Id varchar(255) not null, UserName varchar(50), Message varchar(512), primary key (Id))
2020-10-07 10:01:15.142  INFO 43304 --- [nio-8081-exec-8] o.h.h.i.QueryTranslatorFactoryInitiator  : HHH000397: Using ASTQueryTranslatorFactory
Hibernate: select chatmessag0_.Id as Id1_0_, chatmessag0_.UserName as UserName2_0_, chatmessag0_.Message as Message3_0_ from ChatMessages chatmessag0_

这是异常和跟踪的顶部：

[nio-8081-exec-6] o.h.p.access.spi.GetterMethodImpl        : HHH000122: IllegalArgumentException in class: org.hiof.chatroom.core.ChatMessage, getter method of property: id
2020-10-07 02:28:59.438 ERROR 47504 --- [nio-8081-exec-6] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.hibernate.PropertyAccessException: IllegalArgumentException occurred calling getter of org.hiof.chatroom.core.ChatMessage.id] with root cause

java.lang.IllegalArgumentException: object is not an instance of declaring class
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_172]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_172]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_172]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_172]
    at org.hibernate.property.access.spi.GetterMethodImpl.get(GetterMethodImpl.java:41) ~[hibernate-core-5.1.0.Final.jar:5.1.0.Final]
    at org.hibernate.tuple.entity.AbstractEntityTuplizer.getIdentifier(AbstractEntityTuplizer.java:223) ~[hibernate-core-5.1.0.Final.jar:5.1.0.Final]
    at org.hibernate.persister.entity.AbstractEntityPersister.getIdentifier(AbstractEntityPersister.java:4633) ~[hibernate-core-5.1.0.Final.jar:5.1.0.Final]
    at org.hibernate.id.Assigned.generate(Assigned.java:32) ~[hibernate-core-5.1.0.Final.jar:5.1.0.Final]
    at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:105) ~[hibernate-core-5.1.0.Final.jar:5.1.0.Final]
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:192) ~[hibernate-core-5.1.0.Final.jar:5.1.0.Final]
    at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:38) ~[hibernate-core-5.1.0.Final.jar:5.1.0.Final]
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:177) ~[hibernate-core-5.1.0.Final.jar:5.1.0.Final]
    at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:32) ~[hibernate-core-5.1.0.Final.jar:5.1.0.Final]
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:73) ~[hibernate-core-5.1.0.Final.jar:5.1.0.Final]
    at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:682) ~[hibernate-core-5.1.0.Final.jar:5.1.0.Final]
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:674) ~[hibernate-core-5.1.0.Final.jar:5.1.0.Final]
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:669) ~[hibernate-core-5.1.0.Final.jar:5.1.0.Final]
    at org.hiof.chatroom.database.ChatMessageRepository.add(ChatMessageRepository.java:21) ~[classes/:na]

这是一个使用 SQL Lite 的超级简单的数据库设置。

唯一的实体是这样映射的：

<class name="org.hiof.chatroom.core.ChatMessage" table="ChatMessages">
    <id name="id" column="Id">
        <generator class="assigned"/>
    </id>
    <property name="user" column="UserName" length="50"/>
    <property name="message" column="Message" length="512"/>
</class>

和实体：

public class ChatMessage {
    private String id;
    private String user;
    private String message;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getUser() {
        return user;
    }

    public void setUser(String user) {
        this.user = user;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }
}

这是一个测试，没有不同的基础设施和配置，而不是（没有）让 Spring 运行应用程序：

public class When_persisting_chat_messages {
    @Test
    public void stores_message() throws Exception {
        DatabaseManager.ensureDatabase("./db/chat-test.db");
        UnitOfWork uow = new UnitOfWork();
        ChatMessageRepository repo = new ChatMessageRepository(uow);
        ChatMessage msg = new ChatMessage();
        String id = UUID.randomUUID().toString();
        msg.setId(id);
        repo.add(msg);
        uow.saveChanges();
        uow.close();
        uow = new UnitOfWork();
        repo = new ChatMessageRepository(uow);
        msg = repo.get(id);
        Assertions.assertNotNull(msg);
    }
}

我相当确定这与在我的UOWStandardServiceRegistryBuilder中设置会话工厂有关。不知道该怎么做。

太晚了，我希望明天为一些学生演示这个，所以如果我离开这篇文章有点偏离 SO 的首选标准，我深表歉意。

[编辑]
回购在这里发布：https ://github.com/lars-erik/hiof-sweat2020-chatroom-demo

[2 天后编辑]
我设法确定了它在 Web 项目中运行时抛出的位置。对于像我这样的 dotnet 开发人员，这闻起来就像我的核心“程序集”（模块）的两个版本被加载到“域”中，并且 ID 属性是从“错误模块的元数据”中读取的。不知道，但看起来就是这样。在该getIdentifier方法中，owner 和 idGetter 都指向同一个类，org.hiof.chatroom.core.ChatMessage. 然而，invoke坚持实例不是 id getter 的声明类。这是跟踪：

get:42, GetterMethodImpl (org.hibernate.property.access.spi)
getIdentifier:230, AbstractEntityTuplizer (org.hibernate.tuple.entity)
getIdentifier:5155, AbstractEntityPersister (org.hibernate.persister.entity)
generate:31, Assigned (org.hibernate.id)
saveWithGeneratedId:115, AbstractSaveEventListener (org.hibernate.event.internal)
saveWithGeneratedOrRequestedId:194, DefaultSaveOrUpdateEventListener (org.hibernate.event.internal)
saveWithGeneratedOrRequestedId:38, DefaultSaveEventListener (org.hibernate.event.internal)
entityIsTransient:179, DefaultSaveOrUpdateEventListener (org.hibernate.event.internal)
performSaveOrUpdate:32, DefaultSaveEventListener (org.hibernate.event.internal)
onSaveOrUpdate:75, DefaultSaveOrUpdateEventListener (org.hibernate.event.internal)
accept:-1, 1659093435 (org.hibernate.internal.SessionImpl$$Lambda$541)
fireEventOnEachListener:102, EventListenerGroupImpl (org.hibernate.event.service.internal)
fireSave:636, SessionImpl (org.hibernate.internal)
save:629, SessionImpl (org.hibernate.internal)
save:624, SessionImpl (org.hibernate.internal)

[编辑十月。11.] 使用 spring 运行时，调试当前显示 ChatMessage 类的两个版本。：/

owner.getClass() = {Class@9587} "class org.hiof.chatroom.core.ChatMessage"
owner.getClass() == getterMethod.getDeclaringClass() = false
org.hiof.chatroom.core.ChatMessage.class = {Class@8446} "class org.hiof.chatroom.core.ChatMessage"
getterMethod.getDeclaringClass() = {Class@8446} "class org.hiof.chatroom.core.ChatMessage"

所有者类的类加载器是“RestartClassLoader”，而声明类加载器是“Launcher$AppClassLoader”。

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1 回答 1

3

This was caused by spring-boot-devtools. It creates a classloader called RestartClassLoader to speed up restarts. However, it messes with Hibernate's metadata reflection giving two instances of the same type when we get to id reflection.

So this ends up being somewhat of a dupe of this and a few others:
Classes loaded by different Classloaders in Spring Boot and Logback

于 2020-10-11T19:20:13.770 回答