java - 增强 hibernate IdentityGenerator 并且不破坏模式导出

Question

我正在尝试将自定义 IdentityGenerator 应用到我的实体，- 如该线程中所建议:

Bypass GeneratedValue in Hibernate (merge data not in db?)

现在，它确实起作用了——好吧，生成器的行为被考虑在内。

尝试执行我的集成测试时，我收到以下错误堆栈跟踪:

org.hibernate.exception.SQLGrammarException: DEFAULT keyword cannot be used as column has no DEFAULT
    at org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert(SQLExceptionTypeDelegate.java:82)
    at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:47)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:125)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:110)
    at org.hibernate.engine.jdbc.internal.proxy.ConnectionProxyHandler.continueInvocation(ConnectionProxyHandler.java:146)
    at org.hibernate.engine.jdbc.internal.proxy.AbstractProxyHandler.invoke(AbstractProxyHandler.java:81)
    at $Proxy52.prepareStatement(Unknown Source)
    at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$2.doPrepare(StatementPreparerImpl.java:105)
    at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:166)
    at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.prepareStatement(StatementPreparerImpl.java:103)
    at org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.prepare(IdentityGenerator.java:89)
    at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:52)
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2757)
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3268)
    at org.hibernate.action.internal.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:78)
    at org.hibernate.engine.spi.ActionQueue.execute(ActionQueue.java:272)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:304)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:195)
    at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:128)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:204)
    at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:55)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:189)
    at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:49)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:90)
    at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:642)
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:635)
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:631)
    at dk.dsa.core.datamodel.entities.IdentityGenerationTest.absent_identifier_gets_generated_by_hibernate(IdentityGenerationTest.java:46)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
    at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74)
    at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:83)
    at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:231)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:174)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: java.sql.SQLSyntaxErrorException: DEFAULT keyword cannot be used as column has no DEFAULT
    at org.hsqldb.jdbc.Util.sqlException(Unknown Source)
    at org.hsqldb.jdbc.Util.sqlException(Unknown Source)
    at org.hsqldb.jdbc.JDBCPreparedStatement.<init>(Unknown Source)
    at org.hsqldb.jdbc.JDBCConnection.prepareStatement(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.hibernate.engine.jdbc.internal.proxy.ConnectionProxyHandler.continueInvocation(ConnectionProxyHandler.java:138)
    ... 51 more
Caused by: org.hsqldb.HsqlException: DEFAULT keyword cannot be used as column has no DEFAULT
    at org.hsqldb.error.Error.error(Unknown Source)
    at org.hsqldb.error.Error.error(Unknown Source)
    at org.hsqldb.ParserDML.compileInsertStatement(Unknown Source)
    at org.hsqldb.ParserCommand.compilePart(Unknown Source)
    at org.hsqldb.ParserCommand.compileStatement(Unknown Source)
    at org.hsqldb.Session.compileStatement(Unknown Source)
    at org.hsqldb.StatementManager.compile(Unknown Source)
    at org.hsqldb.Session.execute(Unknown Source)
    ... 58 more

我能够追踪到它与生成的架构没有标识列这一事实有关。

查看由 Hibernate 的 SchemaExport'er 生成的“创建”语句，验证这是问题所在:

create table TranslationNamespace (
   id bigint not null, 
   description varchar(255), 
   name varchar(255) not null, 
   primary key (id), 
   unique (name)
)

如果您从我的实体中删除自定义的 IdentityGenerator，则会生成以下“创建”语句:

create table TranslationNamespace (
   id bigint generated by default as identity (start with 1), 
   description varchar(255), 
   name varchar(255) not null, 
   primary key (id), 
   unique (name)
) 

我知道问题出在哪里，它与 org.hibernate.mapping.SimpleValue 确定列是否为标识字段的方式有关，更具体地说是这段代码(行226-227):

return identifierGeneratorFactory.getIdentifierGeneratorClass( identifierGeneratorStrategy )
            .equals( IdentityGenerator.class );

由于我的自定义 IdentityGenerator 是基于扩展 IdentityGenerator 类，因此类型不等于IdentityGenerator.class。我似乎找不到解决此问题的方法。

非常感谢任何意见，如如何修改此问题。

附加信息:

技术(及其各自的版本)

• hibernate (4.0.1.Final 版)
• HSQLDB(2.2.8 版)
• Spring 测试(v. 3.1.0.RELEASE)

Answer 1

这个问题似乎在 Hibernate 5 中得到了修复。代码如下所示。

IdentityGenerator.class.isAssignableFrom(identifierGeneratorFactory.getIdentifierGeneratorClass( identifierGeneratorStrategy ));