CODEWITHSUNDEEP
springdaoautowiredtransactional
Dave A
Dave A

Reputation: 2830

Adding @Transactional causes "java.lang.ClassCastException-->java.lang.Class cannot be cast to java.lang.reflect.ParameterizedType" exception

I'm using Spring 3.2.11.RELEASE. I have a class like the following ...

@Repository("AssessmentImageDao")
@Transactional
public class MyObjectDao extends GenericDAO<MyObject> 
{

in which the super class has

public GenericDAO() {
    this.persistentClass = (Class<T>) ((ParameterizedType) this.getClass().getGenericSuperclass()).getActualTypeArguments()[0];
}

However, this causes the exception below ...

[ERROR]: org.springframework.test.context.TestContextManager - Caught exception while allowing TestExecutionListener [org.springframework.test.context.support.DependencyInjectionTestExecutionListener@62b9a65b] to prepare test instance [com.myco.MyTest@7a252cf1]
java.lang.IllegalStateException: Failed to load ApplicationContext
    at org.springframework.test.context.CacheAwareContextLoaderDelegate.loadContext(CacheAwareContextLoaderDelegate.java:99)
    at org.springframework.test.context.TestContext.getApplicationContext(TestContext.java:122)
    at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:109)
    at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:75)
    at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:321)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:211)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:288)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:284)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:231)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:88)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    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:309)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:174)
    at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:264)
    at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:153)
    at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:124)
    at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(ForkedBooter.java:200)
    at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:153)
    at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:103)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'MyObjectDao' defined in file [/Users/davea/Dropbox/workspace/core/target/classes/org/mainco/subco/myproject/dao/MyObjectDao.class]: Initialization of bean failed; nested exception is org.springframework.aop.framework.AopConfigException: Could not generate CGLIB subclass of class [class org.mainco.subco.myproject.dao.MyObjectDao]: Common causes of this problem include using a final class or a non-visible class; nested exception is org.springframework.cglib.core.CodeGenerationException: java.lang.ClassCastException-->java.lang.Class cannot be cast to java.lang.reflect.ParameterizedType
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:529)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:293)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:290)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:191)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:636)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:934)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479)
    at org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:120)
    at org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:60)
    at org.springframework.test.context.support.AbstractDelegatingSmartContextLoader.delegateLoading(AbstractDelegatingSmartContextLoader.java:102)
    at org.springframework.test.context.support.AbstractDelegatingSmartContextLoader.loadContext(AbstractDelegatingSmartContextLoader.java:246)
    at org.springframework.test.context.CacheAwareContextLoaderDelegate.loadContextInternal(CacheAwareContextLoaderDelegate.java:64)
    at org.springframework.test.context.CacheAwareContextLoaderDelegate.loadContext(CacheAwareContextLoaderDelegate.java:91)
    ... 25 more

Is there any way to rewrite the constructor to avoid this kind of exception or do some other global configuration that would fix the problem? I'm trying to invoice recoding each of the sub-classes of the GenericDao class.

Upvotes: 0

Views: 1144

Answers (2)

Piotr Gwiazda
Piotr Gwiazda

Reputation: 12222

You can also use polymorphism and create a public abstract Class<? extends MyObject> getHandledType() method in GenericDAO and make every implementation introduce itself.

Or use Spring Data.

Upvotes: 0

Ian Roberts
Ian Roberts

Reputation: 122394

The problem is that the @Transactional annotation is implemented by adding another layer to the class hierarchy - a proxy class that extends MyObjectDao to implement the transactional behaviour. For objects of this proxy class, this.getClass() is the proxy class, whose getGenericSuperclass() is MyObjectDao itself, not the parameterized type GenericDAO<MyObject>.

You could change the logic a bit, so that you keep looking up the getGenericSuperclass chain until you find a ParameterizedType - if the parent is a Class you try the grandparent, and so on.

Alternatively, see if you can defer the superclass lookup until the first time you actually need it (when one of the GenericDAO methods is called) rather than doing it in the constructor. While the generated proxy class extends MyObjectDao it never actually calls any of its superclass methods on this. The proxy intercepts all method calls, does the transaction logic, then delegates the business logic to a separate target object that is an instance of MyObjectDao directly rather than a subclass.

Upvotes: 2

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