springboot jpa repository.save(obj) 不能为空，测试中出现 NullPointerException
springboot jpa repository.save(obj) must not be null, NullPointerException in test
我在为实际使用正常的 Kotlin 项目编写单元测试时遇到问题。但是，我的单元测试会抛出异常错误。当我在测试中调用我的保存服务时，它会抛出 java.lang.NullPointerException: movieRepository.save(movie) must not be null。我不确定 'must not be null' 指的是什么项目，因为我记录了 movieRepository 和 movie 都具有一些价值。
附加信息：只有当我添加新条目时，它才会抛出 NPE 错误。但是，当我执行更新（也使用 .save(movie)）时，测试正常进行。使用 .findAll() 和 .deleteById() 等其他功能进行测试工作正常。
以下是代码片段：
Movie.kt
@Table(name="movie")
@Entity
data class Movie(
@Id
@Column(name="id")
@GeneratedValue(strategy = GenerationType.IDENTITY)
val id: Int? = null,
val name: String,
val type: String,
)
MovieService.kt
@Service
class MovieService {
@Autowired
private lateinit var movieRepository: MovieRepository;
fun addMovie(movie: Movie): Movie {
return movieRepository.save(movie)
}
}
MovieServiceTest.kt
@ExtendWith(MockitoExtension::class)
@MockitoSettings(strictness = Strictness.LENIENT)
internal class MovieServiceTest {
@Mock
private lateinit var mockMovieRepository: MovieRepository;
@InjectMocks
private lateinit var movieServiceTest: MovieService;
// Mock Values
val mockName = "mockName";
val mockType = "mockType";
val mockMovie = Movie(name = mockName, type = mockType);
@Test
fun addMovie() {
val result = movieServiceTest.addMovie(mockMovie);
val movieArgumentCaptor: ArgumentCaptor<Movie> = ArgumentCaptor.forClass(Movie::class.java);
verify(mockMovieRepository).save(movieArgumentCaptor.capture());
val capturedMovie = movieArgumentCaptor.value;
verify(mockMovieRepository).save(capturedMovie);
verify(result.name == mockName)
}
}
错误信息
java.lang.NullPointerException: movieRepository.save(movie) must not be null
at com.example.Whosebug.MovieService.addMovie(MovieService.kt:18)
at com.example.Whosebug.MovieServiceTest.addMovie(MovieServiceTest.kt:43)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:567)
at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:725)
at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:149)
at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:140)
at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:84)
at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod[=14=](ExecutableInvoker.java:115)
at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke[=14=](ExecutableInvoker.java:105)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:106)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37)
at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:104)
at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:98)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod(TestMethodTestDescriptor.java:214)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:210)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:135)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:66)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:151)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:141)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:139)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:155)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:141)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:139)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:155)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:141)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:139)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:35)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:54)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:107)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:88)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute[=14=](EngineExecutionOrchestrator.java:54)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:67)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:52)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:114)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:86)
at org.junit.platform.launcher.core.DefaultLauncherSession$DelegatingLauncher.execute(DefaultLauncherSession.java:86)
at org.junit.platform.launcher.core.SessionPerRequestLauncher.execute(SessionPerRequestLauncher.java:53)
at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:71)
at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:235)
at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54)
Process finished with exit code 255
你的测试有 2 个错误。
第一个错误： 你必须模拟你的 repository.save 方法。 Kotlin 说 "java.lang.NullPointerException: movieRepository.save(movie) must not be null" 因为如果不模拟 movieRepository.save 方法将 return 为空。不幸的是，您的 MovieService.addMovie 不能 return 为空。因此 nullPointerException。
您可以通过这种方式模拟存储库调用：
Mockito.`when`(mockMovieRepository.save(mockMovie)).thenReturn(mockMovie)
第二个错误：在你最后的断言中verify(result.name == mockName)
我猜你想断言 result.name 等于 mockName.You 可以为此目的使用 junit 断言 (https://junit.org/junit5/docs/current/user-guide/#writing-tests-assertions)
Mockito.verify 旨在验证某些行为是否发生，例如某个方法被调用一次或多次。
总结：
@Test
fun addMovie() {
Mockito.`when`(mockMovieRepository.save(mockMovie)).thenReturn(mockMovie)
val result = movieServiceTest.addMovie(mockMovie);
val movieArgumentCaptor: ArgumentCaptor<Movie> = ArgumentCaptor.forClass(Movie::class.java);
verify(mockMovieRepository).save(movieArgumentCaptor.capture());
val capturedMovie = movieArgumentCaptor.value;
verify(mockMovieRepository).save(capturedMovie);
assertEquals(result.name, mockName)
}
我在为实际使用正常的 Kotlin 项目编写单元测试时遇到问题。但是，我的单元测试会抛出异常错误。当我在测试中调用我的保存服务时，它会抛出 java.lang.NullPointerException: movieRepository.save(movie) must not be null。我不确定 'must not be null' 指的是什么项目，因为我记录了 movieRepository 和 movie 都具有一些价值。
附加信息：只有当我添加新条目时，它才会抛出 NPE 错误。但是，当我执行更新（也使用 .save(movie)）时，测试正常进行。使用 .findAll() 和 .deleteById() 等其他功能进行测试工作正常。
以下是代码片段：
Movie.kt
@Table(name="movie")
@Entity
data class Movie(
@Id
@Column(name="id")
@GeneratedValue(strategy = GenerationType.IDENTITY)
val id: Int? = null,
val name: String,
val type: String,
)
MovieService.kt
@Service
class MovieService {
@Autowired
private lateinit var movieRepository: MovieRepository;
fun addMovie(movie: Movie): Movie {
return movieRepository.save(movie)
}
}
MovieServiceTest.kt
@ExtendWith(MockitoExtension::class)
@MockitoSettings(strictness = Strictness.LENIENT)
internal class MovieServiceTest {
@Mock
private lateinit var mockMovieRepository: MovieRepository;
@InjectMocks
private lateinit var movieServiceTest: MovieService;
// Mock Values
val mockName = "mockName";
val mockType = "mockType";
val mockMovie = Movie(name = mockName, type = mockType);
@Test
fun addMovie() {
val result = movieServiceTest.addMovie(mockMovie);
val movieArgumentCaptor: ArgumentCaptor<Movie> = ArgumentCaptor.forClass(Movie::class.java);
verify(mockMovieRepository).save(movieArgumentCaptor.capture());
val capturedMovie = movieArgumentCaptor.value;
verify(mockMovieRepository).save(capturedMovie);
verify(result.name == mockName)
}
}
错误信息
java.lang.NullPointerException: movieRepository.save(movie) must not be null
at com.example.Whosebug.MovieService.addMovie(MovieService.kt:18)
at com.example.Whosebug.MovieServiceTest.addMovie(MovieServiceTest.kt:43)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:567)
at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:725)
at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:149)
at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:140)
at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:84)
at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod[=14=](ExecutableInvoker.java:115)
at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke[=14=](ExecutableInvoker.java:105)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:106)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37)
at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:104)
at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:98)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod(TestMethodTestDescriptor.java:214)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:210)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:135)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:66)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:151)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:141)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:139)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:155)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:141)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:139)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:155)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:141)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:139)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:35)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:54)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:107)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:88)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute[=14=](EngineExecutionOrchestrator.java:54)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:67)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:52)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:114)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:86)
at org.junit.platform.launcher.core.DefaultLauncherSession$DelegatingLauncher.execute(DefaultLauncherSession.java:86)
at org.junit.platform.launcher.core.SessionPerRequestLauncher.execute(SessionPerRequestLauncher.java:53)
at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:71)
at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:235)
at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54)
Process finished with exit code 255
你的测试有 2 个错误。
第一个错误： 你必须模拟你的 repository.save 方法。 Kotlin 说 "java.lang.NullPointerException: movieRepository.save(movie) must not be null" 因为如果不模拟 movieRepository.save 方法将 return 为空。不幸的是，您的 MovieService.addMovie 不能 return 为空。因此 nullPointerException。
您可以通过这种方式模拟存储库调用：
Mockito.`when`(mockMovieRepository.save(mockMovie)).thenReturn(mockMovie)
第二个错误：在你最后的断言中verify(result.name == mockName)
我猜你想断言 result.name 等于 mockName.You 可以为此目的使用 junit 断言 (https://junit.org/junit5/docs/current/user-guide/#writing-tests-assertions)
Mockito.verify 旨在验证某些行为是否发生，例如某个方法被调用一次或多次。
总结：
@Test
fun addMovie() {
Mockito.`when`(mockMovieRepository.save(mockMovie)).thenReturn(mockMovie)
val result = movieServiceTest.addMovie(mockMovie);
val movieArgumentCaptor: ArgumentCaptor<Movie> = ArgumentCaptor.forClass(Movie::class.java);
verify(mockMovieRepository).save(movieArgumentCaptor.capture());
val capturedMovie = movieArgumentCaptor.value;
verify(mockMovieRepository).save(capturedMovie);
assertEquals(result.name, mockName)
}