Grails 3.2.4 拒绝保存域实例：java.lang.IllegalArgumentException：对象不是声明 class 的实例
Grails 3.2.4 refuses to save domain instance: java.lang.IllegalArgumentException: object is not an instance of declaring class
我正在从 Grails 2.4.4 升级到 Grails 3.2.4。
我已经设置了几个工厂来帮助我进行测试，角色工厂工作正常，它在创建用户之前运行。然后我有以下代码：
println "create user."
def testUser = new User(username: 'admin@mail.com', firstName: "admin", lastName: "admin", email: "email@mail.com")
println "User. :: " + testUser
println "User class. :: " + testUser.getClass().toString()
println("User Errors: " + testUser.errors)
testUser.save()
println "create user2."
def testUser2 = new User(username: 'trade@mail.com', email: 'trade@mail.com', firstName: "trade", lastName: "trade").save()
其中输出为：
create user
User. :: Person: admin@mail.com
User class. :: class UserManage.User
User Errors: grails.validation.ValidationErrors: 0 errors
2017-01-10 10:21:18.400 ERROR --- [ main] o.s.boot.SpringApplication : Application startup failed
java.lang.IllegalArgumentException: object is not an instance of declaring class
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springsource.loaded.ri.ReflectiveInterceptor.jlrMethodInvoke(ReflectiveInterceptor.java:1426)
at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:93)
at groovy.lang.MetaBeanProperty.getProperty(MetaBeanProperty.java:62)
at groovy.lang.MetaClassImpl.invokePropertyOrMissing(MetaClassImpl.java:1245)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1217)
at groovy.lang.ExpandoMetaClass.invokeMethod(ExpandoMetaClass.java:1125)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1024)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:812)
at org.grails.validation.ConstrainedPropertyBuilder.doInvokeMethod(ConstrainedPropertyBuilder.java:74)
at groovy.util.BuilderSupport.invokeMethod(BuilderSupport.java:67)
at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeOnDelegationObjects(ClosureMetaClass.java:446)
at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:369)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1024)
at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.callCurrent(PogoMetaClassSite.java:69)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:166)
at UserManage.User$__clinit__closure2.doCall(User.groovy:79)
at UserManage.User$__clinit__closure2.doCall(User.groovy)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springsource.loaded.ri.ReflectiveInterceptor.jlrMethodInvoke(ReflectiveInterceptor.java:1426)
at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:93)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325)
at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:294)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1024)
at groovy.lang.Closure.call(Closure.java:414)
at UserManage.User$__clinit__closure2.call(User.groovy)
at groovy.lang.Closure.call(Closure.java:408)
at UserManage.User$__clinit__closure2.call(User.groovy)
at org.grails.validation.DefaultConstraintEvaluator.evaluateConstraintsMap(DefaultConstraintEvaluator.java:240)
at org.grails.validation.DefaultConstraintEvaluator.evaluateConstraints(DefaultConstraintEvaluator.java:132)
at org.grails.validation.DefaultConstraintEvaluator.evaluateConstraints(DefaultConstraintEvaluator.java:119)
at org.grails.validation.DefaultConstraintEvaluator.evaluate(DefaultConstraintEvaluator.java:108)
at org.grails.core.DefaultGrailsDomainClass.initializeConstraints(DefaultGrailsDomainClass.java:755)
at org.grails.core.DefaultGrailsDomainClass.getConstrainedProperties(DefaultGrailsDomainClass.java:746)
at org.grails.validation.GrailsDomainClassValidator.validate(GrailsDomainClassValidator.java:76)
at org.grails.orm.hibernate.AbstractHibernateGormInstanceApi.save(AbstractHibernateGormInstanceApi.groovy:122)
at org.grails.datastore.gorm.GormInstanceApi.save(GormInstanceApi.groovy:116)
at org.grails.datastore.gorm.GormEntity$Trait$Helper.save(GormEntity.groovy:98)
at org.grails.datastore.gorm.GormEntity$Trait$Helper$save.call(Unknown Source)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:125)
at UserManage.User.save(User.groovy)
at UserManage.User.save(User.groovy)
at org.grails.datastore.gorm.GormEntity$save[=13=].call(Unknown Source)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:117)
at groovy.Factories.UserFactory.Build(UserFactory.groovy:18)
at groovy.Factories.UserFactory$Build.call(Unknown Source)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:117)
at agripedia.BootStrap$_closure1.doCall(BootStrap.groovy:24)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springsource.loaded.ri.ReflectiveInterceptor.jlrMethodInvoke(ReflectiveInterceptor.java:1426)
at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:93)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325)
at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:294)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1024)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1089)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1024)
at groovy.lang.Closure.call(Closure.java:414)
at groovy.lang.Closure.call(Closure.java:408)
at grails.util.Environment.evaluateEnvironmentSpecificBlock(Environment.java:516)
at grails.util.Environment.executeForEnvironment(Environment.java:509)
at grails.util.Environment.executeForCurrentEnvironment(Environment.java:485)
at org.grails.web.servlet.boostrap.DefaultGrailsBootstrapClass.callInit(DefaultGrailsBootstrapClass.java:62)
at org.grails.web.servlet.context.GrailsConfigUtils.executeGrailsBootstraps(GrailsConfigUtils.java:65)
at org.grails.plugins.web.servlet.context.BootStrapClassRunner.onStartup(BootStrapClassRunner.groovy:53)
at grails.boot.config.GrailsApplicationPostProcessor.onApplicationEvent(GrailsApplicationPostProcessor.groovy:256)
at grails.boot.config.GrailsApplicationPostProcessor.onApplicationEvent(GrailsApplicationPostProcessor.groovy)
at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:166)
at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:138)
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:383)
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:337)
at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:882)
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.finishRefresh(EmbeddedWebApplicationContext.java:144)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:545)
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:761)
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:371)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:315)
at grails.boot.GrailsApp.run(GrailsApp.groovy:83)
at grails.boot.GrailsApp.run(GrailsApp.groovy:387)
at grails.boot.GrailsApp.run(GrailsApp.groovy:374)
at grails.boot.GrailsApp$run.call(Unknown Source)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:133)
at agripedia.Application.main(Application.groovy:8)
保存方法失败，不是验证错误。
我的 class 结构是抽象的 APEntity class 并且用户 class 继承自 APEntity class。此代码在 Grails 2.4.4
中运行良好
如果有任何可以修复错误的建议，我将不胜感激。
正在构造的 class 实例是 User 但看到的类型是 UserManage.User
at UserManage.User.save(User.groovy)
根据我的经验，Grails 3 比 Grails 2 类型安全得多，而且对歧义的容忍度更低。明确：User a = new User()
事实证明，验证是问题所在。
在确保类型正确后，我禁用了所有约束。一旦约束被关闭，验证问题就变得很明显了。在我的情况下，在 Grails 2 中我会简单地为未指定的日期输入一个空值。在 grails 3 中，这似乎是不允许的，因此我给了它一个默认值，并且验证问题得到了解决。
只是添加我关于这个主题的注释，因为这是 post 让我把很多注意力放在导致问题的错误方面，希望能节省其他人花时间试图识别某些东西似乎没有正确定义。
input a null value for a date that is not specified
这不完全正确。
我花了很长时间试图跟踪问题是在 3.2.8 下创建的虚拟站点的位置，并尝试重新创建 hasMany 和具有可为空的真实对象。如果是这种情况，那么需要做很多额外的工作来填充不需要的空值，并最终用不需要的东西填充数据库并破坏代码的其他逻辑。
无论哪种方式，据我所知，到目前为止，这个问题是由两件事在 grails 3.2 中引起的：
https://github.com/grails/grails-core/issues/10428
这是当域 class 对象具有
String aUser
static constraints = {
aUser(nullable:true)
}
以上在3以后的版本中已经修复2.X
最近 https://github.com/grails/grails-core/issues/10600 当域对象具有 _underscore
时出现了一个新问题
String _user
static constraints = {
_user(nullable:true)
}
这似乎需要修复，希望在 3.9 中得到修复
意思是如果你有 _objects 可以肯定地说它很可能在 3.2.X > - < 3.2.8 (was working in 3.1.10) 下崩溃。
我正在从 Grails 2.4.4 升级到 Grails 3.2.4。
我已经设置了几个工厂来帮助我进行测试，角色工厂工作正常，它在创建用户之前运行。然后我有以下代码：
println "create user."
def testUser = new User(username: 'admin@mail.com', firstName: "admin", lastName: "admin", email: "email@mail.com")
println "User. :: " + testUser
println "User class. :: " + testUser.getClass().toString()
println("User Errors: " + testUser.errors)
testUser.save()
println "create user2."
def testUser2 = new User(username: 'trade@mail.com', email: 'trade@mail.com', firstName: "trade", lastName: "trade").save()
其中输出为：
create user
User. :: Person: admin@mail.com
User class. :: class UserManage.User
User Errors: grails.validation.ValidationErrors: 0 errors
2017-01-10 10:21:18.400 ERROR --- [ main] o.s.boot.SpringApplication : Application startup failed
java.lang.IllegalArgumentException: object is not an instance of declaring class
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springsource.loaded.ri.ReflectiveInterceptor.jlrMethodInvoke(ReflectiveInterceptor.java:1426)
at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:93)
at groovy.lang.MetaBeanProperty.getProperty(MetaBeanProperty.java:62)
at groovy.lang.MetaClassImpl.invokePropertyOrMissing(MetaClassImpl.java:1245)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1217)
at groovy.lang.ExpandoMetaClass.invokeMethod(ExpandoMetaClass.java:1125)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1024)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:812)
at org.grails.validation.ConstrainedPropertyBuilder.doInvokeMethod(ConstrainedPropertyBuilder.java:74)
at groovy.util.BuilderSupport.invokeMethod(BuilderSupport.java:67)
at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeOnDelegationObjects(ClosureMetaClass.java:446)
at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:369)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1024)
at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.callCurrent(PogoMetaClassSite.java:69)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:166)
at UserManage.User$__clinit__closure2.doCall(User.groovy:79)
at UserManage.User$__clinit__closure2.doCall(User.groovy)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springsource.loaded.ri.ReflectiveInterceptor.jlrMethodInvoke(ReflectiveInterceptor.java:1426)
at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:93)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325)
at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:294)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1024)
at groovy.lang.Closure.call(Closure.java:414)
at UserManage.User$__clinit__closure2.call(User.groovy)
at groovy.lang.Closure.call(Closure.java:408)
at UserManage.User$__clinit__closure2.call(User.groovy)
at org.grails.validation.DefaultConstraintEvaluator.evaluateConstraintsMap(DefaultConstraintEvaluator.java:240)
at org.grails.validation.DefaultConstraintEvaluator.evaluateConstraints(DefaultConstraintEvaluator.java:132)
at org.grails.validation.DefaultConstraintEvaluator.evaluateConstraints(DefaultConstraintEvaluator.java:119)
at org.grails.validation.DefaultConstraintEvaluator.evaluate(DefaultConstraintEvaluator.java:108)
at org.grails.core.DefaultGrailsDomainClass.initializeConstraints(DefaultGrailsDomainClass.java:755)
at org.grails.core.DefaultGrailsDomainClass.getConstrainedProperties(DefaultGrailsDomainClass.java:746)
at org.grails.validation.GrailsDomainClassValidator.validate(GrailsDomainClassValidator.java:76)
at org.grails.orm.hibernate.AbstractHibernateGormInstanceApi.save(AbstractHibernateGormInstanceApi.groovy:122)
at org.grails.datastore.gorm.GormInstanceApi.save(GormInstanceApi.groovy:116)
at org.grails.datastore.gorm.GormEntity$Trait$Helper.save(GormEntity.groovy:98)
at org.grails.datastore.gorm.GormEntity$Trait$Helper$save.call(Unknown Source)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:125)
at UserManage.User.save(User.groovy)
at UserManage.User.save(User.groovy)
at org.grails.datastore.gorm.GormEntity$save[=13=].call(Unknown Source)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:117)
at groovy.Factories.UserFactory.Build(UserFactory.groovy:18)
at groovy.Factories.UserFactory$Build.call(Unknown Source)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:117)
at agripedia.BootStrap$_closure1.doCall(BootStrap.groovy:24)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springsource.loaded.ri.ReflectiveInterceptor.jlrMethodInvoke(ReflectiveInterceptor.java:1426)
at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:93)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325)
at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:294)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1024)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1089)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1024)
at groovy.lang.Closure.call(Closure.java:414)
at groovy.lang.Closure.call(Closure.java:408)
at grails.util.Environment.evaluateEnvironmentSpecificBlock(Environment.java:516)
at grails.util.Environment.executeForEnvironment(Environment.java:509)
at grails.util.Environment.executeForCurrentEnvironment(Environment.java:485)
at org.grails.web.servlet.boostrap.DefaultGrailsBootstrapClass.callInit(DefaultGrailsBootstrapClass.java:62)
at org.grails.web.servlet.context.GrailsConfigUtils.executeGrailsBootstraps(GrailsConfigUtils.java:65)
at org.grails.plugins.web.servlet.context.BootStrapClassRunner.onStartup(BootStrapClassRunner.groovy:53)
at grails.boot.config.GrailsApplicationPostProcessor.onApplicationEvent(GrailsApplicationPostProcessor.groovy:256)
at grails.boot.config.GrailsApplicationPostProcessor.onApplicationEvent(GrailsApplicationPostProcessor.groovy)
at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:166)
at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:138)
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:383)
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:337)
at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:882)
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.finishRefresh(EmbeddedWebApplicationContext.java:144)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:545)
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:761)
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:371)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:315)
at grails.boot.GrailsApp.run(GrailsApp.groovy:83)
at grails.boot.GrailsApp.run(GrailsApp.groovy:387)
at grails.boot.GrailsApp.run(GrailsApp.groovy:374)
at grails.boot.GrailsApp$run.call(Unknown Source)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:133)
at agripedia.Application.main(Application.groovy:8)
保存方法失败，不是验证错误。
我的 class 结构是抽象的 APEntity class 并且用户 class 继承自 APEntity class。此代码在 Grails 2.4.4
中运行良好如果有任何可以修复错误的建议，我将不胜感激。
正在构造的 class 实例是 User 但看到的类型是 UserManage.User
at UserManage.User.save(User.groovy)
根据我的经验，Grails 3 比 Grails 2 类型安全得多，而且对歧义的容忍度更低。明确：User a = new User()
事实证明，验证是问题所在。
在确保类型正确后，我禁用了所有约束。一旦约束被关闭，验证问题就变得很明显了。在我的情况下，在 Grails 2 中我会简单地为未指定的日期输入一个空值。在 grails 3 中，这似乎是不允许的，因此我给了它一个默认值，并且验证问题得到了解决。
只是添加我关于这个主题的注释，因为这是 post 让我把很多注意力放在导致问题的错误方面，希望能节省其他人花时间试图识别某些东西似乎没有正确定义。
input a null value for a date that is not specified
这不完全正确。
我花了很长时间试图跟踪问题是在 3.2.8 下创建的虚拟站点的位置，并尝试重新创建 hasMany 和具有可为空的真实对象。如果是这种情况，那么需要做很多额外的工作来填充不需要的空值，并最终用不需要的东西填充数据库并破坏代码的其他逻辑。
无论哪种方式，据我所知，到目前为止，这个问题是由两件事在 grails 3.2 中引起的：
https://github.com/grails/grails-core/issues/10428
这是当域 class 对象具有
String aUser
static constraints = {
aUser(nullable:true)
}
以上在3以后的版本中已经修复2.X
最近 https://github.com/grails/grails-core/issues/10600 当域对象具有 _underscore
时出现了一个新问题String _user
static constraints = {
_user(nullable:true)
}
这似乎需要修复，希望在 3.9 中得到修复
意思是如果你有 _objects 可以肯定地说它很可能在 3.2.X > - < 3.2.8 (was working in 3.1.10) 下崩溃。