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POPolymorphism with Objectify
 

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    <p>I am trying to use Objectify with a set of classes that inherit from an abstract base class:</p> <pre><code>class Container { @Id Long id; @Embedded Set&lt;MyAbstract&gt; children = new HashSet&lt;MyAbstract&gt;(); } @Entity abstract class MyAbstract { @Id Long id; } @Subclass class Derived1 extends MyAbstract {} @Subclass class Derived2 extends MyAbstract {} </code></pre> <p>Any idea how to code for this situation? I get the following error:</p> <pre><code>java.lang.RuntimeException: java.lang.InstantiationException at com.googlecode.objectify.impl.TypeUtils.newInstance(TypeUtils.java:321) at com.googlecode.objectify.impl.load.EmbeddedMultivalueSetter.safeSet(EmbeddedMultivalueSetter.java:89) at com.googlecode.objectify.impl.load.CollisionDetectingSetter.set(CollisionDetectingSetter.java:37) at com.googlecode.objectify.impl.Transmog.load(Transmog.java:326) at com.googlecode.objectify.impl.ConcreteEntityMetadata.toObject(ConcreteEntityMetadata.java:212) at com.googlecode.objectify.impl.QueryImpl$ToObjectIterator.translate(QueryImpl.java:611) at com.googlecode.objectify.impl.QueryImpl$ToObjectIterator.translate(QueryImpl.java:1) at com.googlecode.objectify.util.TranslatingIterator.next(TranslatingIterator.java:35) at com.googlecode.objectify.impl.QueryImpl.get(QueryImpl.java:368) at com.foodblox.server.model.ObjectifyTest.creation(ObjectifyTest.java:49) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) 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.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28) at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:31) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:76) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50) 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.junit.runners.ParentRunner.run(ParentRunner.java:236) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:49) 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.lang.InstantiationException at sun.reflect.InstantiationExceptionConstructorAccessorImpl.newInstance(InstantiationExceptionConstructorAccessorImpl.java:30) at java.lang.reflect.Constructor.newInstance(Constructor.java:513) at com.googlecode.objectify.impl.TypeUtils.newInstance(TypeUtils.java:319) ... 33 more </code></pre>
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