java - Spring Data JPA findById() throwing ClassCastException

Question

I have a method that is using findById() method of Spring Data JPA. However, this method is returning ClassCastException on line number 1 of the getSupportedKey() method where I am calling findById():

MySupportedKey cannot be cast to java.util.Optional

private MySupportedKey getSupportedKey(String tenant, String key) {
        Optional<MySupportedKey> mySupportedKeyOptional = mySupportedKeyRepository.findById(new MySupportedKeyId(tenant, key));
        MySupportedKey mySupportedKey= null;
        if(mySupportedKeyOptional !=null) {
             mySupportedKey= mySupportedKeyOptional.orElse(null);
        }
        return mySupportedKey;
    }

I have been beating my head for a long time but I am not getting anything. Please help me in getting this resolved. I am using spring-data-jpa: 2.0.8.RELEASE.

Adding the Repository Source Code:

public interface MySupportedKeyRepository extends JpaRepository<MySupportedKey, MySupportedKeyId> {

List<MySupportedKey> findByIdTenant(@NotNull String tenant);
}

Adding the complete stack trace of error:

java.lang.ClassCastException: com.test.service.user.entity.MySupportedKey cannot be cast to java.util.Optional
at com.test.service.user.repository.MySupportedKeyRepository$MockitoMock$1304362870.findById(Unknown Source)
at com.test.service.user.repository.MySupportedKeyRepository$MockitoMock$1304362870.findById(Unknown Source)
at com.test.service.user.userpreferences.PreferencesServiceImpl.getSupportedKey(PreferencesServiceImpl.java:217)
at com.test.service.user.userpreferences.PreferencesServiceImpl.updateUserPreferences(PreferencesServiceImpl.java:167)
at com.test.service.user.userpreferences.PreferencesServiceImpl.lambda$2(PreferencesServiceImpl.java:92)
at java.util.ArrayList.forEach(Unknown Source)
at com.test.service.user.userpreferences.PreferencesServiceImpl.updateUserPreferences(PreferencesServiceImpl.java:92)
at com.test.service.user.preferences.PreferencesServiceImplTest.updateUserPreferences(PreferencesServiceImplTest.java:300)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.mockito.internal.junit.JUnitRule$1.evaluateSafely(JUnitRule.java:52)
at org.mockito.internal.junit.JUnitRule$1.evaluate(JUnitRule.java:43)
at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)
at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)
at org.springframework.test.context.junit4.statements.RunPrepareTestInstanceCallbacks.evaluate(RunPrepareTestInstanceCallbacks.java:64)
at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)
at org.springframework.test.context.junit4.statements.SpringFailOnTimeout.evaluate(SpringFailOnTimeout.java:87)
at org.springframework.test.context.junit4.statements.ProfileValueChecker.evaluate(ProfileValueChecker.java:103)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
at org.springframework.test.context.junit4.statements.ProfileValueChecker.evaluate(ProfileValueChecker.java:103)
at org.springframework.test.context.junit4.rules.SpringClassRule$TestContextManagerCacheEvictor.evaluate(SpringClassRule.java:230)
at org.junit.rules.RunRules.evaluate(RunRules.java:20)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:538)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:760)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:460)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:206)

标签： javaspringspring-data-jpaoptionalclasscastexception

Answer 1

You set up a Mockito mock for the repository and probably told it to return a MySupportedKey instance when findById gets called. But since findById is supposed to return an Optional you now get the exception.

You can see that this is coming from Mockito in the very first two lines of the stack trace.

java.lang.ClassCastException: com.test.service.user.entity.MySupportedKey cannot be cast to java.util.Optional
at com.test.service.user.repository.MySupportedKeyRepository$MockitoMock$1304362870.findById(Unknown Source)