具有泛型和多级继承的JPA。设置单表策略。 org.hibernate.MappingException：无法获得构造函数 [英] JPA with generics and multilevel inheritance. Set Single Table strategy. org.hibernate.MappingException: Could not get constructor
本文介绍了具有泛型和多级继承的JPA。设置单表策略。 org.hibernate.MappingException：无法获得构造函数的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我的实体有问题。
一切正常，直到我改变了类继承：
GenericModel - >保险 - >医生
GenericModel - >保险 - >护士
到：
GenericModel - >保险 - >责任>医生
GenericModel - >保险 - >责任>护士
GenericModel - >保险 - >合同
我做了什么：
责任相关元素外化为新的责任类。
合同类，它继承自 Insurance class。
Insurance class中使用了与 Liability 有关的一些功能/元素。
以下是具有新结构的实体：
@MappedSuperclass
public abstract class GenericModel< T extends GenericModel> {
@Id @GeneratedValue（strategy = GenerationType.IDENTITY）public Long id;
@Transient受保护的类< T> entityClass;
public GenericModel（）{
类obtainClass = getClass（）;
类型genericSuperclass = null; （;;）{
genericSuperclass = obtainClass.getGenericSuperclass（）;
if（genericSuperclass instanceof ParameterizedType）{
break;
}
obtainClass = obtainClass.getSuperclass（）;
}
ParameterizedType genericSuperclass_ =（ParameterizedType）genericSuperclass;
entityClass =（（Class）（（Class）genericSuperclass_.getActualTypeArguments（）[0]））;
@Entity
@DiscriminatorColumn（name =type）
@DiscriminatorValue（value =A）
@Table（name =mi__Insurance）
@Inheritance（strategy = InheritanceType.SINGLE_TABLE）
公共类Insurance< T延伸保险>扩展GenericModel< T> {
public Insurance（）{
super（）;
this.status = Status.STARTED.getId（）;
this.statusDescription = Status.getDescriptionBy（this.status）;
this.statusColor = Status.getColorBy（status）;
this.statusAction = Status.getActionBy（status）;
this.progress = 0;
this.policyHolder_Answer = null;
this.policyHolder = 1;
this.filledParts = 1;
this.totalParts = 2;
@Entity
@DiscriminatorValue（value =C）
公共类合同延伸Insurance< Contract> {
public Contract（）{
super（）;
this.setColor（危险）;
this.setIcon（）;
this.setFormUrl（）;
@Entity
@DiscriminatorValue（value =L）
公共类责任延伸Insurance< Liability> {
public Liability（）{
super（）;
this.legal_Answer = null;
this.freely = 0;
this.mandatory = 0;
this.hiv = 0;
this.legal = 0;
$ b $ / code $ / pre
@Entity
@DiscriminatorValue（value =D）
public class Doctor延伸责任{
public Doctor（） {
super（）;
this.setType（Type.DOCTOR）;
this.setColor（success）;
this.setIcon（）;
this.setFormUrl（）;
this.hiv_Answer = null;
code
一切看起来都不错，但不幸的是我收到了一个错误：
play.api.UnexpectedException：意外的异常[PersistenceException：[ PersistenceUnit：defaultPersistenceUnit]无法构建EntityManagerFactory]
导致：javax.persistence.PersistenceException：[PersistenceUnit：defaultPersistenceUnit]无法构建EntityManagerFactory
导致：org.hibernate.MappingException：无法获取org的构造函数org.hibernate.InstantiationException：.hibernate.persister.entity.SingleTableEntityPersister
。通过致无法实例测试objectmyInsurance.models.Insurance
产生的原因：java.lang.reflect.InvocationTargetException：空
由于：java.lang.ClassCastException：sun.reflect.generics.reflectiveObjects.TypeVariableImpl无法转换为java.lang.Class
这是完整的堆栈跟踪：
！ @ 6mped6a12 - 内部服务器错误，用于（GET）[/] - >
play.api.UnexpectedException：意外的异常[的PersistenceException：[PersistenceUnit：defaultPersistenceUnit]无法建立的EntityManagerFactory]在play.core.ReloadableApplication $$ anonfun $得到$ 1 $$ anonfun $
申请$ 1 $$ anonfun $ 1.apply（ApplicationProvider.scala：148）〜[play_2.10.jar：2.2.6]
at play.core.ReloadableApplication $$ anonfun $ get $ 1 $$ anonfun $ apply $ 1 $$ anonfun $ 1.apply（ApplicationProvider.scala：112）〜[play_2.10.jar：2.2.6]
at scala.Option.map（Option.scala：145）〜[scala-library.jar：na]
在play.core.ReloadableApplication $$ anonfun $ get $ 1 $$ anonfun $ apply $ 1.apply（ApplicationProvider.scala：112）〜[play_2.10.jar：2.2.6]
在玩。 core.ReloadableApplication $$ anonfun $ get $ 1 $$ anonfun $ apply $ 1.apply（ApplicationProvider.scala：110）〜[play_2.10.jar：2.2.6]
at scala.util.Success.flatMap（Try .scala：200）〜[scala-library.jar：na]
在play.core.ReloadableApplication $$ anonfun $ get $ 1.apply（ApplicationProvider.scala：11 0）〜[play_2.10.jar：2.2.6]
在play.core.ReloadableApplication $$ anonfun $ get $ 1.apply（ApplicationProvider.scala：102）〜[play_2.10.jar：2.2.6 ]
at scala.concurrent.impl.Future $ PromiseCompletingRunnable.liftedTree1 $ 1（Future.scala：24）〜[scala-library.jar：na]
at scala.concurrent.impl.Future $ PromiseCompletingRunnable。运行（Future.scala：24）〜[scala-library.jar：na]
at scala.concurrent.forkjoin.ForkJoinTask $ AdaptedRunnableAction.exec（ForkJoinTask.java:1361）〜[scala-library.jar：na ]
at scala.concurrent.forkjoin.ForkJoinTask.doExec（ForkJoinTask.java:260）〜[scala-library.jar：na]
at scala.concurrent.forkjoin.ForkJoinPool $ WorkQueue.runTask（ForkJoinPool .java：1339）〜[scala-library.jar：na]
at scala.concurrent.forkjoin.ForkJoinPool.runWorker（ForkJoinPool.java:1979）〜[scala-library.jar：na]
在scala.concurrent.forkjoin.ForkJoinWorkerThread.run（ForkJoinWorkerThread.java:107）〜[scala-library.jar：na]
引起：javax.persistence.PersistenceException：[PersistenceUnit：defaultPersistenceUnit]无法在org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory（Ejb3Configuration.java:915）〜[hibernate-entitymanager-4.2.0.CR1.jar]上构建EntityManagerFactory
：4.2.0.CR1]
at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory（Ejb3Configuration.java:890）〜[hibernate-entitymanager-4.2.0.CR1.jar：4.2.0.CR1]
at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory（HibernatePersistence.java:57）〜[hibernate-entitymanager-4.2.0.CR1.jar：4.2.0.CR1]
在javax.persistence.Persistence。 createEntityManagerFactory（Persistence.java:63）〜[hibernate-jpa-2.0-api.jar：1.0.1.Final]
at javax.persistence.Persistence.createEntityManagerFactory（Persistence.java:47）〜[hibernate-jpa -2.0-api.jar：1.0.1.Final]
在play.db.jpa.JPAPlugin.onStart（JPAPlugin.java:35）〜[play-java-jpa_2.10.jar：2.2.6]
在play.api.Play $$ anon fun $ start $ 1 $$ anonfun $ apply $ mcV $ sp $ 1.apply（Play.scala：88）〜[play_2.10.jar：2.2.6]
at play.api.Play $$ anonfun $ start $ 1 $$ anonfun $ apply $ mcV $ sp $ 1.apply（Play.scala：88）〜[play_2.10.jar：2.2.6]
at scala.collection.immutable.List.foreach（List.scala ：318）〜[scala-library.jar：na]
at play.api.Play $$ anonfun $ start $ 1.apply $ mcV $ sp（Play.scala：88）〜[play_2.10.jar： 2.2.6]
at play.api.Play $$ anonfun $ start $ 1.apply（Play.scala：88）〜[play_2.10.jar：2.2.6]
at play.api。 Play $$ anonfun $ start $ 1.apply（Play.scala：88）〜[play_2.10.jar：2.2.6]
at play.utils.Threads $ .withContextClassLoader（Threads.scala：18）〜[ play_2.10.jar：2.2.6]
在play.api.Play $ .start（Play.scala：87）〜[play_2.10.jar：2.2.6]
在play.core .ReloadableApplication $$ anonfun $ get $ 1 $$ anonfun $ apply $ 1 $$ anonfun $ 1.apply（ApplicationProvider.scala：139）〜[play_2.10.jar：2.2.6]
... 14个常用框架省略
引起：org.hibernate.MappingException：无法获取构造为在org.hibernate.persister.internal.PersisterFactoryImpl.create（PersisterFactoryImpl.java:185）org.hibernate.persister.entity.SingleTableEntityPersister
〜[冬眠核-4.2.0.CR1.jar：4.2。 0.CR1]
at org.hibernate.persister.internal.PersisterFactoryImpl.createEntityPersister（PersisterFactoryImpl.java:135）〜[hibernate-core-4.2.0.CR1.jar：4.2.0.CR1]
在org.hibernate.internal.SessionFactoryImpl。< init>（SessionFactoryImpl.java:385）〜[hibernate-core-4.2.0.CR1.jar：4.2.0.CR1]
at org.hibernate。 cfg.Configuration.buildSessionFactory（Configuration.java:1742）〜[hibernate-core-4.2.0.CR1.jar：4.2.0.CR1]
at org.hibernate.ejb.EntityManagerFactoryImpl。< init>（ EntityManagerFactoryImpl.java:94）〜[hibernate-entitymanager-4.2.0.CR1.jar：4.2.0.CR1]
at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory（Ejb3Configuration.java:905）〜[hibernate -entitymanager-4.2.0.CR1.jar：4.2.0.CR1]
... 28 org.hibernate.InstantiationException：在org.hibernate.engine.internal.UnsavedValueFactory.instantiate（UnsavedValueFactory.java:49）不能实例测试objectmyInsurance.models.Insurance
〜[通过公共帧省略了
引起的冬眠芯-4.2.0.CR1.jar：4.2.0.CR1]在org.hibernate.engine.internal.UnsavedValueFactory.getUnsavedIdentifierValue（UnsavedValueFactory.java:68）
〜[冬眠核-4.2.0 .CR1.jar：4.2.0.CR1]
在org.hibernate.tuple.PropertyFactory.buildIdentifierProperty（PropertyFactory.java:75）〜[hibernate-core-4.2.0.CR1.jar：4.2.0。 （EntityMetamodel.java:145）〜[hibernate-core-4.2.0.CR1.jar：4.2.0.CR1] $ b [or] $ b at org.hibernate.persister.entity.AbstractEntityPersister。< init>（AbstractEntityPersister.java:507）〜[hibernate-core-4.2.0.CR1.jar：4.2.0.CR1]
at org .hibernate.persister.entity.SingleTableEntityPersister<初始化>（SingleTableEntityPe rsister.java:146）〜[hibernate-core-4.2.0.CR1.jar：4.2.0.CR1]
at sun.reflect.NativeConstructorAccessorImpl.newInstance0（Native Method）〜[na：1.7.0_80]
at sun.reflect.NativeConstructorAccessorImpl.newInstance（NativeConstructorAccessorImpl.java:57）〜[na：1.7.0_80]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance（DelegatingConstructorAccessorImpl.java:45）〜[na： 1.7.0_80]
at java.lang.reflect.Constructor.newInstance（Constructor.java:526）〜[na：1.7.0_80]
at org.hibernate.persister.internal.PersisterFactoryImpl.create（ PersisterFactoryImpl.java:163）〜[hibernate-core-4.2.0.CR1.jar：4.2.0.CR1]
... 33个常见帧被忽略
由java.lang.reflect引起。 InvocationTargetException：null
at sun.reflect.NativeConstructorAccessorImpl.newInstance0（Native Method）〜[na：1.7.0_80]
at sun.reflect.NativeConstructorAccessorImpl.newInstance（NativeConstructorAccessorImpl.java:57）〜[na： 1.7.0_80]
在sun.reflect.DelegatingConstructorAccessorImpl.newInstance（DelegatingConstructorAccessorImpl.java:45）〜[NA：1.7.0_80]在java.lang.reflect.Constructor.newInstance（Constructor.java:526）
〜[NA：1.7。 0_80]
在org.hibernate.engine.internal.UnsavedValueFactory.instantiate（UnsavedValueFactory.java:46）〜[hibernate-core-4.2.0.CR1.jar：4.2.0.CR1]
。 .. 43共同框架省略
引起：java.lang.ClassCastException：sun.reflect.generics.reflectiveObjects.TypeVariableImpl无法在泛型.models.GenericModel转换为java.lang.Class
。< init>（GenericModel.java:51）〜[na：na]
at myInsurance.models.Insurance。< init>（Insurance.java:151）〜[na：na]
... 48个常用框架省略
a href =https://stackoverflow.com/q/31557468/2794446>这里是我之前发表的关于继承泛型的文章，它引发了我的这个问题。
也许我的构造函数有一些问题。我不知道，也许我应该在某处声明参数类型的构造函数？
请帮助我。
EDIT-工作解决方案
@MappedSuperclass
公共抽象类GenericModel< T扩展GenericModel> ; {
/ **
*适用于嵌套/内部类和类型化参数类
* /
public GenericModel（）{
类obtainClass = getClass（）;
类型genericSuperclass = null; （;;）{
genericSuperclass = obtainClass.getGenericSuperclass（）;
if（genericSuperclass instanceof ParameterizedType）{
break;
}
obtainClass = obtainClass.getSuperclass（）;
}
ParameterizedType genericSuperclass_ =（ParameterizedType）genericSuperclass;
try {
entityClass =（（Class）（（Class）genericSuperclass_.getActualTypeArguments（）[0]））;
} catch（ClassCastException e）{
entityClass = guessEntityClassFromTypeParametersClassTypedArgument（）;
code
$ b $ hr
/ **
*用于扩展GenericModel< ExtendingClass< TypeArgument>>
*如果传递给GenericModel TypeParameter，它不是实际的类，而是TypedParameter的类
* @return
* /
public Class< T> guessEntityClassFromTypeParametersClassTypedArgument（）{
return ClassUtil.getActualTypeBinding（getClass（），GenericModel.class，0）;
package org.fastnate.data.util;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.NoSuchElementException;
/ **
*助手检查课程。
*
* @author Tobias Liefke
* /
public final class ClassUtil {
private static< I>类型getActualTypeArgument（final Class< ;? extends I> instanceClass，final Class< I> superClass，
final int argumentIndex）{
final List< Type> parents = new ArrayList<>（）;
parents.add（instanceClass.getGenericSuperclass（））;
parents.addAll（Arrays.asList（instanceClass.getGenericInterfaces（）））; （最终类型parentType：父母）{
final Class<？>
parentClass = parentType instanceof ParameterizedType？ （Class<>）（（ParameterizedType）parentType）
.getRawType（）：（Class<> parentType;
//首先检查我们是否找到超类或接口
if（superClass.equals（parentClass））{
//我们找到了请求的超类 - 使用绑定$（b $ b）return（（ParameterizedType）parentType）.getActualTypeArguments（）[argumentIndex];
} else if（parentClass！= null&& superClass.isAssignableFrom（parentClass））{
// Else step up
final Type type = getActualTypeArgument（parentClass.asSubclass（superClass）， superClass，argumentIndex）;
if（类型instanceof Class）{
返回类型;
} else if（type instanceof TypeVariable）{
return（（ParameterizedType）parentType）.getActualTypeArguments（）[Arrays.asList（
parentClass.getTypeParameters（））。indexOf（type）];
}
}
}
返回null;
}
/ **
*解析在超类中指定并在子类中绑定的泛型类型的实际绑定。
*
* @param instanceClass
*实现类
* @param superClass
*指定泛型类型变量的超类或接口
* @ param argumentIndex
*超类定义中类型变量的索引（0 =第一个类型变量）
* @返回instanceClass中变量的绑定类
* /
公共静态< T，I>类< T> getActualTypeBinding（final Class< ;? extends I> instanceClass，
final Class< I> superClass，final int argumentIndex）{
Type type = getActualTypeArgument（instanceClass，superClass，argumentIndex）; （类型instanceof TypeVariable<>）{
type =（（TypeVariable<>）类型）.getBounds（）[0];
}
if（type instanceof ParameterizedType）{
type =（（ParameterizedType）type）.getRawType（）; （类型instanceof Class<>）{
return（Class< T>）类型的
}
;
}
抛出new NoSuchElementException（+ instanceClass中找不到+ argumentIndex +。+ superClass
+参数的绑定。
private ClassUtil（）{
//助手类
}
}
解决方案这与JPA无关。
如果你看一下stacktrace：
.lang.ClassCastException：
sun.reflect.generics.reflectiveObjects.TypeVariableImpl无法在generic.models.GenericModel上转换为java.lang.Class
。< init>（GenericModel.java:51）〜 [na：na]
它引用了这一行：
$ b $（< pre> entityClass =（（Class）（（Class）genericSuperclass_.getActualTypeArguments（）[0]））;
Insurance 的实际类型参数不是一个显式类，但是一个类型变量。你不能将它转换成类。
如果你想找到你的类的参数的实际绑定 - 我已经为加藤法尼： ClassUtil.getActualTypeBinding ：
ClassUtil.getActualTypeBinding（getClass（），GenericModel.class，0）;
I have problem with my entity.
Everything works fine until I've changed classes inheritance from:
GenericModel -> Insurance -> Doctor
GenericModel -> Insurance -> Nurse
to:
GenericModel -> Insurance -> Liability > Doctor
GenericModel -> Insurance -> Liability > Nurse
GenericModel -> Insurance -> Contract
What have I done:
- I've externalise some
Liability releated elements to new Liability class.
- I've added
Contract class, which inheritade from Insurance class.
- I've took some functionality/elements related to
Liability from Insurance class.
Here are my entities with new structure:
@MappedSuperclass
public abstract class GenericModel<T extends GenericModel> {
@Id @GeneratedValue(strategy = GenerationType.IDENTITY) public Long id;
@Transient protected Class<T> entityClass;
public GenericModel() {
Class obtainedClass = getClass();
Type genericSuperclass = null;
for(;;) {
genericSuperclass = obtainedClass.getGenericSuperclass();
if(genericSuperclass instanceof ParameterizedType) {
break;
}
obtainedClass = obtainedClass.getSuperclass();
}
ParameterizedType genericSuperclass_ = (ParameterizedType) genericSuperclass;
entityClass = ((Class) ((Class) genericSuperclass_.getActualTypeArguments()[0]));
}
}
@Entity
@DiscriminatorColumn(name="type")
@DiscriminatorValue(value="A")
@Table(name="mi__Insurance")
@Inheritance(strategy=InheritanceType.SINGLE_TABLE)
public class Insurance<T extends Insurance> extends GenericModel<T> {
public Insurance() {
super();
this.status = Status.STARTED.getId();
this.statusDescription = Status.getDescriptionBy(this.status);
this.statusColor = Status.getColorBy(status);
this.statusAction = Status.getActionBy(status);
this.progress = 0;
this.policyHolder_Answer = null;
this.policyHolder = 1;
this.filledParts = 1;
this.totalParts = 2;
}
}
@Entity
@DiscriminatorValue(value="C")
public class Contract extends Insurance<Contract> {
public Contract() {
super();
this.setColor("danger");
this.setIcon();
this.setFormUrl();
}
}
@Entity
@DiscriminatorValue(value="L")
public class Liability extends Insurance<Liability> {
public Liability() {
super();
this.legal_Answer = null;
this.freely = 0;
this.mandatory = 0;
this.hiv = 0;
this.legal = 0;
}
}
@Entity
@DiscriminatorValue(value="D")
public class Doctor extends Liability {
public Doctor() {
super();
this.setType(Type.DOCTOR);
this.setColor("success");
this.setIcon();
this.setFormUrl();
this.hiv_Answer = null;
}
}
Everything looks ok for me, but unfortunately I am getting an errors:
play.api.UnexpectedException: Unexpected exception[PersistenceException: [PersistenceUnit: defaultPersistenceUnit] Unable to build EntityManagerFactory]
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: defaultPersistenceUnit] Unable to build EntityManagerFactory
Caused by: org.hibernate.MappingException: Could not get constructor for org.hibernate.persister.entity.SingleTableEntityPersister
Caused by: org.hibernate.InstantiationException: could not instantiate test objectmyInsurance.models.Insurance
Caused by: java.lang.reflect.InvocationTargetException: null
Caused by: java.lang.ClassCastException: sun.reflect.generics.reflectiveObjects.TypeVariableImpl cannot be cast to java.lang.Class
Here is full stack trace:
! @6mped6a12 - Internal server error, for (GET) [/] ->
play.api.UnexpectedException: Unexpected exception[PersistenceException: [PersistenceUnit: defaultPersistenceUnit] Unable to build EntityManagerFactory]
at play.core.ReloadableApplication$$anonfun$get$1$$anonfun$apply$1$$anonfun$1.apply(ApplicationProvider.scala:148) ~[play_2.10.jar:2.2.6]
at play.core.ReloadableApplication$$anonfun$get$1$$anonfun$apply$1$$anonfun$1.apply(ApplicationProvider.scala:112) ~[play_2.10.jar:2.2.6]
at scala.Option.map(Option.scala:145) ~[scala-library.jar:na]
at play.core.ReloadableApplication$$anonfun$get$1$$anonfun$apply$1.apply(ApplicationProvider.scala:112) ~[play_2.10.jar:2.2.6]
at play.core.ReloadableApplication$$anonfun$get$1$$anonfun$apply$1.apply(ApplicationProvider.scala:110) ~[play_2.10.jar:2.2.6]
at scala.util.Success.flatMap(Try.scala:200) ~[scala-library.jar:na]
at play.core.ReloadableApplication$$anonfun$get$1.apply(ApplicationProvider.scala:110) ~[play_2.10.jar:2.2.6]
at play.core.ReloadableApplication$$anonfun$get$1.apply(ApplicationProvider.scala:102) ~[play_2.10.jar:2.2.6]
at scala.concurrent.impl.Future$PromiseCompletingRunnable.liftedTree1$1(Future.scala:24) ~[scala-library.jar:na]
at scala.concurrent.impl.Future$PromiseCompletingRunnable.run(Future.scala:24) ~[scala-library.jar:na]
at scala.concurrent.forkjoin.ForkJoinTask$AdaptedRunnableAction.exec(ForkJoinTask.java:1361) ~[scala-library.jar:na]
at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260) ~[scala-library.jar:na]
at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339) ~[scala-library.jar:na]
at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979) ~[scala-library.jar:na]
at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107) ~[scala-library.jar:na]
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: defaultPersistenceUnit] Unable to build EntityManagerFactory
at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:915) ~[hibernate-entitymanager-4.2.0.CR1.jar:4.2.0.CR1]
at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:890) ~[hibernate-entitymanager-4.2.0.CR1.jar:4.2.0.CR1]
at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:57) ~[hibernate-entitymanager-4.2.0.CR1.jar:4.2.0.CR1]
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:63) ~[hibernate-jpa-2.0-api.jar:1.0.1.Final]
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:47) ~[hibernate-jpa-2.0-api.jar:1.0.1.Final]
at play.db.jpa.JPAPlugin.onStart(JPAPlugin.java:35) ~[play-java-jpa_2.10.jar:2.2.6]
at play.api.Play$$anonfun$start$1$$anonfun$apply$mcV$sp$1.apply(Play.scala:88) ~[play_2.10.jar:2.2.6]
at play.api.Play$$anonfun$start$1$$anonfun$apply$mcV$sp$1.apply(Play.scala:88) ~[play_2.10.jar:2.2.6]
at scala.collection.immutable.List.foreach(List.scala:318) ~[scala-library.jar:na]
at play.api.Play$$anonfun$start$1.apply$mcV$sp(Play.scala:88) ~[play_2.10.jar:2.2.6]
at play.api.Play$$anonfun$start$1.apply(Play.scala:88) ~[play_2.10.jar:2.2.6]
at play.api.Play$$anonfun$start$1.apply(Play.scala:88) ~[play_2.10.jar:2.2.6]
at play.utils.Threads$.withContextClassLoader(Threads.scala:18) ~[play_2.10.jar:2.2.6]
at play.api.Play$.start(Play.scala:87) ~[play_2.10.jar:2.2.6]
at play.core.ReloadableApplication$$anonfun$get$1$$anonfun$apply$1$$anonfun$1.apply(ApplicationProvider.scala:139) ~[play_2.10.jar:2.2.6]
... 14 common frames omitted
Caused by: org.hibernate.MappingException: Could not get constructor for org.hibernate.persister.entity.SingleTableEntityPersister
at org.hibernate.persister.internal.PersisterFactoryImpl.create(PersisterFactoryImpl.java:185) ~[hibernate-core-4.2.0.CR1.jar:4.2.0.CR1]
at org.hibernate.persister.internal.PersisterFactoryImpl.createEntityPersister(PersisterFactoryImpl.java:135) ~[hibernate-core-4.2.0.CR1.jar:4.2.0.CR1]
at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:385) ~[hibernate-core-4.2.0.CR1.jar:4.2.0.CR1]
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1742) ~[hibernate-core-4.2.0.CR1.jar:4.2.0.CR1]
at org.hibernate.ejb.EntityManagerFactoryImpl.<init>(EntityManagerFactoryImpl.java:94) ~[hibernate-entitymanager-4.2.0.CR1.jar:4.2.0.CR1]
at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:905) ~[hibernate-entitymanager-4.2.0.CR1.jar:4.2.0.CR1]
... 28 common frames omitted
Caused by: org.hibernate.InstantiationException: could not instantiate test objectmyInsurance.models.Insurance
at org.hibernate.engine.internal.UnsavedValueFactory.instantiate(UnsavedValueFactory.java:49) ~[hibernate-core-4.2.0.CR1.jar:4.2.0.CR1]
at org.hibernate.engine.internal.UnsavedValueFactory.getUnsavedIdentifierValue(UnsavedValueFactory.java:68) ~[hibernate-core-4.2.0.CR1.jar:4.2.0.CR1]
at org.hibernate.tuple.PropertyFactory.buildIdentifierProperty(PropertyFactory.java:75) ~[hibernate-core-4.2.0.CR1.jar:4.2.0.CR1]
at org.hibernate.tuple.entity.EntityMetamodel.<init>(EntityMetamodel.java:145) ~[hibernate-core-4.2.0.CR1.jar:4.2.0.CR1]
at org.hibernate.persister.entity.AbstractEntityPersister.<init>(AbstractEntityPersister.java:507) ~[hibernate-core-4.2.0.CR1.jar:4.2.0.CR1]
at org.hibernate.persister.entity.SingleTableEntityPersister.<init>(SingleTableEntityPersister.java:146) ~[hibernate-core-4.2.0.CR1.jar:4.2.0.CR1]
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.7.0_80]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) ~[na:1.7.0_80]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.7.0_80]
at java.lang.reflect.Constructor.newInstance(Constructor.java:526) ~[na:1.7.0_80]
at org.hibernate.persister.internal.PersisterFactoryImpl.create(PersisterFactoryImpl.java:163) ~[hibernate-core-4.2.0.CR1.jar:4.2.0.CR1]
... 33 common frames omitted
Caused by: java.lang.reflect.InvocationTargetException: null
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.7.0_80]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) ~[na:1.7.0_80]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.7.0_80]
at java.lang.reflect.Constructor.newInstance(Constructor.java:526) ~[na:1.7.0_80]
at org.hibernate.engine.internal.UnsavedValueFactory.instantiate(UnsavedValueFactory.java:46) ~[hibernate-core-4.2.0.CR1.jar:4.2.0.CR1]
... 43 common frames omitted
Caused by: java.lang.ClassCastException: sun.reflect.generics.reflectiveObjects.TypeVariableImpl cannot be cast to java.lang.Class
at generic.models.GenericModel.<init>(GenericModel.java:51) ~[na:na]
at myInsurance.models.Insurance.<init>(Insurance.java:151) ~[na:na]
... 48 common frames omitted
If it somehow helps, here is my previous post about Inheritance with Generics, which draws me to this issue.
Perhaps there is some issue with my contructors. I dont know, maybe I Should somewhere declare parameter typed constructor?
Please help me.
EDIT- Working solution
@MappedSuperclass
public abstract class GenericModel<T extends GenericModel> {
/**
* Works for nested/inner classes and Typed Parametered Classes
*/
public GenericModel() {
Class obtainedClass = getClass();
Type genericSuperclass = null;
for(;;) {
genericSuperclass = obtainedClass.getGenericSuperclass();
if(genericSuperclass instanceof ParameterizedType) {
break;
}
obtainedClass = obtainedClass.getSuperclass();
}
ParameterizedType genericSuperclass_ = (ParameterizedType) genericSuperclass;
try {
entityClass = ((Class) ((Class) genericSuperclass_.getActualTypeArguments()[0]));
} catch (ClassCastException e) {
entityClass = guessEntityClassFromTypeParametersClassTypedArgument();
}
}
}
/**
* Use in case of extending GenericModel<ExtendingClass<TypeArgument>>
* Use if passed into GenericModel TypeParameter which isn't actual class, but Class with TypedParameter
* @return
*/
public Class<T> guessEntityClassFromTypeParametersClassTypedArgument() {
return ClassUtil.getActualTypeBinding(getClass(), GenericModel.class, 0);
}
package org.fastnate.data.util;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.NoSuchElementException;
/**
* Helper for inspection of classes.
*
* @author Tobias Liefke
*/
public final class ClassUtil {
private static <I> Type getActualTypeArgument(final Class<? extends I> instanceClass, final Class<I> superClass,
final int argumentIndex) {
final List<Type> parents = new ArrayList<>();
parents.add(instanceClass.getGenericSuperclass());
parents.addAll(Arrays.asList(instanceClass.getGenericInterfaces()));
for (final Type parentType : parents) {
final Class<?> parentClass = parentType instanceof ParameterizedType ? (Class<?>) ((ParameterizedType) parentType)
.getRawType() : (Class<?>) parentType;
// First check if we found the super class or interface
if (superClass.equals(parentClass)) {
// We found the requested super class - use the binding
return ((ParameterizedType) parentType).getActualTypeArguments()[argumentIndex];
} else if (parentClass != null && superClass.isAssignableFrom(parentClass)) {
// Else step up
final Type type = getActualTypeArgument(parentClass.asSubclass(superClass), superClass, argumentIndex);
if (type instanceof Class) {
return type;
} else if (type instanceof TypeVariable) {
return ((ParameterizedType) parentType).getActualTypeArguments()[Arrays.asList(
parentClass.getTypeParameters()).indexOf(type)];
}
}
}
return null;
}
/**
* Resolves the actual binding of a generic type that was specified in a superclass and bound in a subclass.
*
* @param instanceClass
* the implementing class
* @param superClass
* the superclass or interface which specifies the generic type variable
* @param argumentIndex
* the index of the type variable in the superclass definition (0 = the first type variable)
* @return the bound class for the variable in instanceClass
*/
public static <T, I> Class<T> getActualTypeBinding(final Class<? extends I> instanceClass,
final Class<I> superClass, final int argumentIndex) {
Type type = getActualTypeArgument(instanceClass, superClass, argumentIndex);
if (type instanceof TypeVariable<?>) {
type = ((TypeVariable<?>) type).getBounds()[0];
}
if (type instanceof ParameterizedType) {
type = ((ParameterizedType) type).getRawType();
}
if (type instanceof Class<?>) {
return (Class<T>) type;
}
throw new NoSuchElementException("Can't find binding for the " + argumentIndex + ". argument of " + superClass
+ " in " + instanceClass);
}
private ClassUtil() {
// Helper class
}
}
解决方案 This has nothing to do with JPA.
If you look at the stacktrace:
Caused by: java.lang.ClassCastException:
sun.reflect.generics.reflectiveObjects.TypeVariableImpl cannot be cast to java.lang.Class
at generic.models.GenericModel.<init>(GenericModel.java:51) ~[na:na]
And it references this line:
entityClass = ((Class) ((Class) genericSuperclass_.getActualTypeArguments()[0]));
The actual type argument of Insurance ist not an explicit class, but a type variable. Sou you can't cast it to a class.
If you would like to find the actual binding for a parameter of your class - I've created that for Fastnate: ClassUtil.getActualTypeBinding:
ClassUtil.getActualTypeBinding(getClass(), GenericModel.class, 0);
这篇关于具有泛型和多级继承的JPA。设置单表策略。 org.hibernate.MappingException：无法获得构造函数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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