Question

我正在尝试为存储库方法编写测试用例。在该测试用例中，我想使用assertEquals()测试调查员的姓名。设置了方法的返回类型，我在每个循环中使用该方法从set中检索结果，然后使用assertEquals（）检查预期和实际结果，但我得到了java.lang.ClassCastException: java.util.HashMap cannot be cast to com.spacestudy.model.Investigator

有人可以告诉我我在测试案例中做错了什么吗？

调查人员资料库

@Query("select new map(invest.sInvestigatorName as sInvestigatorName)"
            + " from Investigator invest")
    Set<Investigator> findSinvestigatorName();

我尝试过这样

@RunWith(SpringRunner.class)
@DataJpaTest
public class TestInvestigatorRepository {

    @Autowired
    public TestEntityManager testEm;

    @Autowired
    InvestigatorRepository investRepo;

    @Test
    public void testFindSinvestigatorName() {

        Investigator invest = new Investigator();
        invest.setsInvestigatorName("abc");
        invest.setnInstId(60);

        Investigator saveInDb = testEm.merge(invest);

        Set<Investigator> getFromDb = investRepo.findSinvestigatorName();

        for(Investigator result : getFromDb) {

            assertEquals(saveInDb.getsInvestigatorName(),result.sInvestigatorName); 
        }     

    }
}

堆栈跟踪

java.lang.ClassCastException: java.util.HashMap cannot be cast to com.spacestudy.model.Investigator
    at com.spacestudy.repository.TestInvestigatorRepository.testFindSinvestigatorName(TestInvestigatorRepository.java:39)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    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.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.SpringRepeat.evaluate(SpringRepeat.java:84)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:252)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94)
    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.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191)
    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)

Answer 1

您指定的HQL查询显式返回一个Map，但是为该方法指定的返回类型指定Set<Investigator>，它们是不兼容的类型，因此会出错。

Spring Data尝试转换类型，但失败了，最后，仅尝试将结果转换为所需的类型。

要解决此问题，您需要使用兼容的类型选项：

让您的查询返回Investigator s。
让查询仅列出以下属性即可返回元组：select invest.sInvestigatorName as sInvestigatorName from Investigator invest。尽管您的“有趣”属性名称可能会引起一些麻烦，但Spring Data应该能够将其映射到Investigator。
由于您实际上只是返回一个属性，因此您最好使该方法返回Set<String>并使用上一点中给出的查询。

java.lang.ClassCastException：无法将java.util.HashMap强制转换为com.spacestudy.model.Investigator

1 个答案: