为什么 Playframework 告诉我它不支持子类化？答案

【问题标题】：Why is Playframework telling me that it doesn't support subclassing?为什么 Playframework 告诉我它不支持子类化？
【发布时间】：2014-01-29 00:31:50
【问题描述】：

我正在尝试嵌入一个较小的类作为更大实体的字段，这是我过去在游戏中使用的东西！ 2.1 但现在 Ebean 在创建模式时给了我一个错误。

这是我的课（很简单，没什么花哨的）：

@Embeddable
public class Pricing implements Serializable {

    private Long value;

    private String currency;

    //getters and setters
}

我正在尝试像这样嵌入它：

@Entity
public class MyEntity extends Model {

    @Id
    @GeneratedValue
    private Long id;

    @Embedded
    private Pricing priceProposed;

    //getters and setters
}

我想要实现的是一个看起来像这样的表格

----------------------------------------------------
| id | priceProposed.value | priceProposed.currency|
----------------------------------------------------
| 1  | 200                 | USD                   |
| 2  | 1200000             | JPY                   |
----------------------------------------------------

如你所见，我没有尝试任何困难的事情。但是我收到以下错误，其中提到不再支持子类化。但我不相信这符合subClassing 的条件，还是我完全错了？

javax.persistence.PersistenceException: Entity type class models.product.Pricing is not an enhanced entity bean. Subclassing is not longer supported in Ebean
    at com.avaje.ebeaninternal.server.deploy.BeanDescriptorManager.checkSubclass(BeanDescriptorManager.java:1482)
    at com.avaje.ebeaninternal.server.deploy.BeanDescriptorManager.setEntityBeanClass(BeanDescriptorManager.java:1433)
    at com.avaje.ebeaninternal.server.deploy.BeanDescriptorManager.createByteCode(BeanDescriptorManager.java:1150)
    at com.avaje.ebeaninternal.server.deploy.BeanDescriptorManager.readDeployAssociations(BeanDescriptorManager.java:1070)
    at com.avaje.ebeaninternal.server.deploy.BeanDescriptorManager.createEmbedded(BeanDescriptorManager.java:475)
    at com.avaje.ebeaninternal.server.deploy.BeanDescriptorManager.readEmbeddedDeployment(BeanDescriptorManager.java:498)
    at com.avaje.ebeaninternal.server.deploy.BeanDescriptorManager.deploy(BeanDescriptorManager.java:234)
    at com.avaje.ebeaninternal.server.core.InternalConfiguration.<init>(InternalConfiguration.java:114)
    at com.avaje.ebeaninternal.server.core.DefaultServerFactory.createServer(DefaultServerFactory.java:204)
    at com.avaje.ebeaninternal.server.core.DefaultServerFactory.createServer(DefaultServerFactory.java:65)
    at com.avaje.ebean.EbeanServerFactory.create(EbeanServerFactory.java:58)
    at play.db.ebean.EbeanPlugin.onStart(EbeanPlugin.java:79)
    at play.api.Play$$anonfun$start$1$$anonfun$apply$mcV$sp$1.apply(Play.scala:88)
    at play.api.Play$$anonfun$start$1$$anonfun$apply$mcV$sp$1.apply(Play.scala:88)
    at scala.collection.immutable.List.foreach(List.scala:318)
    at play.api.Play$$anonfun$start$1.apply$mcV$sp(Play.scala:88)
    at play.api.Play$$anonfun$start$1.apply(Play.scala:88)
    at play.api.Play$$anonfun$start$1.apply(Play.scala:88)
    at play.utils.Threads$.withContextClassLoader(Threads.scala:18)
    at play.api.Play$.start(Play.scala:87)
    at play.api.Play.start(Play.scala)
    at play.test.Helpers.start(Helpers.java:359)
    at framework.AbstractPlayApplicationTest.setup(AbstractPlayApplicationTest.java:19)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:24)
    at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:74)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:202)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:65)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)

谁能告诉我发生了什么？这与什么有关？有人看到我做错了什么吗（距离我上一个 Ebean+Play! 项目已经过去一年了，所以我可能会忘记一些非常愚蠢的事情）？

【问题讨论】：

标签： java playframework ebean

【解决方案1】：

如果你使用@Entity注解，你不必扩展Ebean的Model类

【讨论】：