如何正确模拟 EntityManager.detach
How to properly mock EntityManager.detach
已更新
我可以使用一些帮助以正确的方式使用 Mockito 在 Spring 中模拟 EntityManager.detach()。我不确定在测试中将什么放入 doAnswer 块。我尝试过的所有操作都会在服务实现中的 em.detach() 调用中导致 NPE。调试器显示 em 和 existing 都是有效的非空对象。 （目标工厂 [javax.persistence.EntityManagerFactory#0 bean] 的共享 EntityManager 代理）。添加了完整的 NPE 堆栈跟踪。
服务class
@Service
@Transactional
public class MyEntityServiceImpl implements MyEntityService {
private final MyDao dao;
@PersistenceContext
private EntityManager em;
public MyEntityServiceImpl(MyDao dao) {
super();
this.dao = dao;
}
public MyDto update(MyDto dto) {
// check preconditions for null and empty
MyEntity existing = dao.findByBusinessKey(dto.getBusinessKey());
if(existing == null) {
throw new NotFoundException();
}
em.detach(existing) // NPE on this line during unit test.
// business logic
MyEntity saved = dao.save(existing);
}
单元测试
@SpringJUnitConfig()
class ServiceImplTest {
@Autowired
private MyEntityServiceImpl service;
@MockBean
private MyDao dao;
@MockBean
EntityManagerFactory emf;
@MockBean
EntityManager em;
@Test
public void givenValidEntity_whenUpdate_thenNoException() {
MyDto existing = MyDto.builder.businessKey("valid business key").build();
when(dao.findByBusinessKey(any(MyDto.class)).thenReturn(existing);
doAnswer( invocation -> {
// what goes in here??!?!?!
}).when(em).detach(any(MyDto.class));
assertDoesNotThrow(() -> {
service.update(existing);
});
}
}
堆栈跟踪
org.opentest4j.AssertionFailedError: Unexpected exception thrown: java.lang.NullPointerException
at org.junit.jupiter.api.AssertDoesNotThrow.createAssertionFailedError(AssertDoesNotThrow.java:83)
at org.junit.jupiter.api.AssertDoesNotThrow.assertDoesNotThrow(AssertDoesNotThrow.java:54)
at org.junit.jupiter.api.AssertDoesNotThrow.assertDoesNotThrow(AssertDoesNotThrow.java:37)
at org.junit.jupiter.api.Assertions.assertDoesNotThrow(Assertions.java:3060)
at MyEntityServiceImpl.givenValidEntity_whenUpdate_thenNoException(MyEntityServiceImpl.java:126)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:688)
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.descriptor.TestMethodTestDescriptor$$Lambda5/0x0000000075d4ab40.apply(Unknown Source)
at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod[=13=](ExecutableInvoker.java:115)
at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall$$Lambda6/0x0000000075b80880.apply(Unknown Source)
at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke[=13=](ExecutableInvoker.java:105)
at org.junit.jupiter.engine.execution.ExecutableInvoker$$Lambda5/0x0000000075f81e80.apply(Unknown Source)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:106)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37)
at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:104)
at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:98)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod(TestMethodTestDescriptor.java:210)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor$$Lambda2/0x0000000075ba46f0.execute(Unknown Source)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:206)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:131)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:65)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:139)
at org.junit.platform.engine.support.hierarchical.NodeTestTask$$Lambda5/0x0000000075d4fad0.execute(Unknown Source)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:129)
at org.junit.platform.engine.support.hierarchical.NodeTestTask$$Lambda4/0x0000000075bb9a70.invoke(Unknown Source)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:127)
at org.junit.platform.engine.support.hierarchical.NodeTestTask$$Lambda3/0x0000000075bb9600.execute(Unknown Source)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService$$Lambda9/0x0000000075d52eb0.accept(Unknown Source)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1541)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:143)
at org.junit.platform.engine.support.hierarchical.NodeTestTask$$Lambda5/0x0000000075d4fad0.execute(Unknown Source)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:129)
at org.junit.platform.engine.support.hierarchical.NodeTestTask$$Lambda4/0x0000000075bb9a70.invoke(Unknown Source)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:127)
at org.junit.platform.engine.support.hierarchical.NodeTestTask$$Lambda3/0x0000000075bb9600.execute(Unknown Source)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService$$Lambda9/0x0000000075d52eb0.accept(Unknown Source)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1541)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:143)
at org.junit.platform.engine.support.hierarchical.NodeTestTask$$Lambda5/0x0000000075d4fad0.execute(Unknown Source)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:129)
at org.junit.platform.engine.support.hierarchical.NodeTestTask$$Lambda4/0x0000000075bb9a70.invoke(Unknown Source)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:127)
at org.junit.platform.engine.support.hierarchical.NodeTestTask$$Lambda3/0x0000000075bb9600.execute(Unknown Source)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:108)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:88)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute[=13=](EngineExecutionOrchestrator.java:54)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator$$Lambda9/0x0000000075c7b430.accept(Unknown Source)
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:96)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:84)
at org.eclipse.jdt.internal.junit5.runner.JUnit5TestReference.run(JUnit5TestReference.java:98)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:40)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:529)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:756)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:452)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:210)
Caused by: java.lang.NullPointerException
at java.base/java.lang.reflect.Method.invoke(Method.java:559)
at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:311)
at com.sun.proxy.$Proxy45.detach(Unknown Source)
at impl.MyEntityServiceImpl.update(MyEntityServiceImpl.java:107)
at MyEntityServiceImpl.lambda[=13=](MyEntityServiceImpl.java:127)
at MyEntityServiceImpl$$Lambda3/0x00000000765fc660.execute(Unknown Source)
at org.junit.jupiter.api.AssertDoesNotThrow.assertDoesNotThrow(AssertDoesNotThrow.java:50)
... 86 more
问题是 EntityManager 没有被模拟。我从@PersistenceContext 改成了构造函数初始化，测试是绿色的。
固定服务class
@Service
@Transactional
public class MyEntityServiceImpl implements MyEntityService {
private final MyDao dao;
private EntityManager em;
public MyEntityServiceImpl(MyDao dao, EntityManager em) {
super();
this.dao = dao;
this.em = em;
}
// other code unchanged from original question
}
已更新
我可以使用一些帮助以正确的方式使用 Mockito 在 Spring 中模拟 EntityManager.detach()。我不确定在测试中将什么放入 doAnswer 块。我尝试过的所有操作都会在服务实现中的 em.detach() 调用中导致 NPE。调试器显示 em 和 existing 都是有效的非空对象。 （目标工厂 [javax.persistence.EntityManagerFactory#0 bean] 的共享 EntityManager 代理）。添加了完整的 NPE 堆栈跟踪。
服务class
@Service
@Transactional
public class MyEntityServiceImpl implements MyEntityService {
private final MyDao dao;
@PersistenceContext
private EntityManager em;
public MyEntityServiceImpl(MyDao dao) {
super();
this.dao = dao;
}
public MyDto update(MyDto dto) {
// check preconditions for null and empty
MyEntity existing = dao.findByBusinessKey(dto.getBusinessKey());
if(existing == null) {
throw new NotFoundException();
}
em.detach(existing) // NPE on this line during unit test.
// business logic
MyEntity saved = dao.save(existing);
}
单元测试
@SpringJUnitConfig()
class ServiceImplTest {
@Autowired
private MyEntityServiceImpl service;
@MockBean
private MyDao dao;
@MockBean
EntityManagerFactory emf;
@MockBean
EntityManager em;
@Test
public void givenValidEntity_whenUpdate_thenNoException() {
MyDto existing = MyDto.builder.businessKey("valid business key").build();
when(dao.findByBusinessKey(any(MyDto.class)).thenReturn(existing);
doAnswer( invocation -> {
// what goes in here??!?!?!
}).when(em).detach(any(MyDto.class));
assertDoesNotThrow(() -> {
service.update(existing);
});
}
}
堆栈跟踪
org.opentest4j.AssertionFailedError: Unexpected exception thrown: java.lang.NullPointerException
at org.junit.jupiter.api.AssertDoesNotThrow.createAssertionFailedError(AssertDoesNotThrow.java:83)
at org.junit.jupiter.api.AssertDoesNotThrow.assertDoesNotThrow(AssertDoesNotThrow.java:54)
at org.junit.jupiter.api.AssertDoesNotThrow.assertDoesNotThrow(AssertDoesNotThrow.java:37)
at org.junit.jupiter.api.Assertions.assertDoesNotThrow(Assertions.java:3060)
at MyEntityServiceImpl.givenValidEntity_whenUpdate_thenNoException(MyEntityServiceImpl.java:126)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:688)
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.descriptor.TestMethodTestDescriptor$$Lambda5/0x0000000075d4ab40.apply(Unknown Source)
at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod[=13=](ExecutableInvoker.java:115)
at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall$$Lambda6/0x0000000075b80880.apply(Unknown Source)
at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke[=13=](ExecutableInvoker.java:105)
at org.junit.jupiter.engine.execution.ExecutableInvoker$$Lambda5/0x0000000075f81e80.apply(Unknown Source)
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:210)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor$$Lambda2/0x0000000075ba46f0.execute(Unknown Source)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:206)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:131)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:65)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:139)
at org.junit.platform.engine.support.hierarchical.NodeTestTask$$Lambda5/0x0000000075d4fad0.execute(Unknown Source)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:129)
at org.junit.platform.engine.support.hierarchical.NodeTestTask$$Lambda4/0x0000000075bb9a70.invoke(Unknown Source)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:127)
at org.junit.platform.engine.support.hierarchical.NodeTestTask$$Lambda3/0x0000000075bb9600.execute(Unknown Source)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService$$Lambda9/0x0000000075d52eb0.accept(Unknown Source)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1541)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:143)
at org.junit.platform.engine.support.hierarchical.NodeTestTask$$Lambda5/0x0000000075d4fad0.execute(Unknown Source)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:129)
at org.junit.platform.engine.support.hierarchical.NodeTestTask$$Lambda4/0x0000000075bb9a70.invoke(Unknown Source)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:127)
at org.junit.platform.engine.support.hierarchical.NodeTestTask$$Lambda3/0x0000000075bb9600.execute(Unknown Source)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService$$Lambda9/0x0000000075d52eb0.accept(Unknown Source)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1541)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:143)
at org.junit.platform.engine.support.hierarchical.NodeTestTask$$Lambda5/0x0000000075d4fad0.execute(Unknown Source)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:129)
at org.junit.platform.engine.support.hierarchical.NodeTestTask$$Lambda4/0x0000000075bb9a70.invoke(Unknown Source)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:127)
at org.junit.platform.engine.support.hierarchical.NodeTestTask$$Lambda3/0x0000000075bb9600.execute(Unknown Source)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:108)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:88)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute[=13=](EngineExecutionOrchestrator.java:54)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator$$Lambda9/0x0000000075c7b430.accept(Unknown Source)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:67)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:52)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:96)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:84)
at org.eclipse.jdt.internal.junit5.runner.JUnit5TestReference.run(JUnit5TestReference.java:98)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:40)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:529)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:756)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:452)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:210)
Caused by: java.lang.NullPointerException
at java.base/java.lang.reflect.Method.invoke(Method.java:559)
at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:311)
at com.sun.proxy.$Proxy45.detach(Unknown Source)
at impl.MyEntityServiceImpl.update(MyEntityServiceImpl.java:107)
at MyEntityServiceImpl.lambda[=13=](MyEntityServiceImpl.java:127)
at MyEntityServiceImpl$$Lambda3/0x00000000765fc660.execute(Unknown Source)
at org.junit.jupiter.api.AssertDoesNotThrow.assertDoesNotThrow(AssertDoesNotThrow.java:50)
... 86 more
问题是 EntityManager 没有被模拟。我从@PersistenceContext 改成了构造函数初始化，测试是绿色的。
固定服务class
@Service
@Transactional
public class MyEntityServiceImpl implements MyEntityService {
private final MyDao dao;
private EntityManager em;
public MyEntityServiceImpl(MyDao dao, EntityManager em) {
super();
this.dao = dao;
this.em = em;
}
// other code unchanged from original question
}