Unit testing JUnit测试用例：java.lang.NullPointerException
我正在尝试使用Unit testing JUnit测试用例：java.lang.NullPointerException,unit-testing,spring-data-jpa,mockito,junit4,Unit Testing,Spring Data Jpa,Mockito,Junit4,我正在尝试使用JUnit和mockito为以下控制器代码编写测试用例。但我得到了空指针异常。我不熟悉JUnit测试。谁能告诉我我做错了什么吗 部门主管 @RestController @RequestMapping("/api.spacestudy.com/SpaceStudy") public class DepartmentController { @Autowired DepartmentService depService;
JUnitmockito @RestController
@RequestMapping("/api.spacestudy.com/SpaceStudy")
public class DepartmentController {
@Autowired
DepartmentService depService;
@CrossOrigin(origins = "http://localhost:4200")
@GetMapping("/LoadDept")
public Department findDeptId() {
return depService.findDeptId();
}
}
@WebMvcTest
public class DepartmentControllerTest {
@Autowired
private MockMvc mockMvc;
@Mock
public DepartmentService depService;
@InjectMocks
DepartmentController departmentController;
@Before
public void setup() throws Exception {
mockMvc = MockMvcBuilders.standaloneSetup(departmentController).build();
}
@Test
public void findDeptIdTest() throws Exception
{
Department department = new Department();
department.setnDeptId(10);
Mockito.when(depService.findDeptId()).thenReturn(department);
mockMvc.perform(get("/api.spacestudy.com/SpaceStudy/LoadDept").accept(MediaType.APPLICATION_JSON))
.andExpect(status().isOk())
.andExpect(jsonPath("$.nDeptId", Matchers.is(10)));
}
}
java.lang.NullPointerException
at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.detectHandlerMethods(AbstractHandlerMethodMapping.java:227)
at org.springframework.test.web.servlet.setup.StandaloneMockMvcBuilder$StaticRequestMappingHandlerMapping.registerHandlers(StandaloneMockMvcBuilder.java:490)
at org.springframework.test.web.servlet.setup.StandaloneMockMvcBuilder.registerMvcSingletons(StandaloneMockMvcBuilder.java:356)
at org.springframework.test.web.servlet.setup.StandaloneMockMvcBuilder.initWebAppContext(StandaloneMockMvcBuilder.java:341)
at org.springframework.test.web.servlet.setup.AbstractMockMvcBuilder.build(AbstractMockMvcBuilder.java:139)
at com.spacestudy.DepartmentControllerTest.setup(DepartmentControllerTest.java:38)
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.RunBefores.evaluate(RunBefores.java:24)
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$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:538)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:760)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:460)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:206)
@WebMvcTest
public class DepartmentControllerTest {
@Autowired
private MockMvc mockMvc;
@Mock
public DepartmentService depService;
@InjectMocks
DepartmentController departmentController;
@Before
public void setup() throws Exception {
mockMvc = MockMvcBuilders.standaloneSetup(departmentController).build();
}
@Test
public void findDeptIdTest() throws Exception
{
Department department = new Department();
department.setnDeptId(10);
Mockito.when(depService.findDeptId()).thenReturn(department);
mockMvc.perform(get("/api.spacestudy.com/SpaceStudy/LoadDept").accept(MediaType.APPLICATION_JSON))
.andExpect(status().isOk())
.andExpect(jsonPath("$.nDeptId", Matchers.is(10)));
}
}
java.lang.NullPointerException
at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.detectHandlerMethods(AbstractHandlerMethodMapping.java:227)
at org.springframework.test.web.servlet.setup.StandaloneMockMvcBuilder$StaticRequestMappingHandlerMapping.registerHandlers(StandaloneMockMvcBuilder.java:490)
at org.springframework.test.web.servlet.setup.StandaloneMockMvcBuilder.registerMvcSingletons(StandaloneMockMvcBuilder.java:356)
at org.springframework.test.web.servlet.setup.StandaloneMockMvcBuilder.initWebAppContext(StandaloneMockMvcBuilder.java:341)
at org.springframework.test.web.servlet.setup.AbstractMockMvcBuilder.build(AbstractMockMvcBuilder.java:139)
at com.spacestudy.DepartmentControllerTest.setup(DepartmentControllerTest.java:38)
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.RunBefores.evaluate(RunBefores.java:24)
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.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)
要解决这个问题，您必须在standaloneSetup（）上提供DepartmentController类的实例。我在进行一些单元测试时遇到了同样的问题，之后，我的问题消失了。尝试这样做：
@Before
public void setup() throws Exception {
mockMvc = MockMvcBuilders.standaloneSetup(new DepartmentController()).build();
}
你们有谷歌spring测试教程吗？是的，我阅读了教程并尝试了上面的代码我的测试正在运行。我将@WebMvcTest更改为@RunWith（SpringJUnit4ClassRunner.class），将此作为答案发布并关闭此答案。好的，我将发布。但是我能告诉我为什么这个问题是因为那个注释吗