我正在为我的控制器编写测试，并且在使用JSON执行post时我正在获得NPE . 相同的JSON适用于Postman（仅添加了转义斜杠），但是jackson（我正在使用的JSON解析器）无法在我的测试中解析它 .
这是 UserControllerTest ：
public class UserControllerTest {
private static final String DEFAULT_REGISTER_JSON = "{\"username\":\"example\"," +
"\"password\":\"example\"," +
"\"email\":\"newUser@example.com\"}";
private UserServiceBean userServiceBeanMock = mock(UserServiceBean.class);
private ObjectMapper mapperDummy = mock(ObjectMapper.class);
private MockMvc mockMvc;
private UserController sut = new UserController(userServiceBeanMock, mapperDummy);
@Before
public void setUp() throws Exception {
this.mockMvc = MockMvcBuilders.standaloneSetup(sut).build();
}
@Test
public void shouldRegisterNewUser() throws Exception {
this.mockMvc.perform(post("/users").content(DEFAULT_REGISTER_JSON).contentType(MediaType.APPLICATION_JSON))
.andExpect(status().isCreated())
.andExpect(content().json("{\"status\":\"User created\"}"));
}
}
这是我的控制器方法来处理该请求： UserController.createUser ：
// CREATE A USER
@PostMapping("/users")
public ResponseEntity<ObjectNode> createUser(@RequestBody User user) {
ObjectNode jsonObject = mapper.createObjectNode();
userService.saveUser(user);
jsonObject.put("status", "User created.");
return new ResponseEntity<>(jsonObject, HttpStatus.CREATED);
}
这是来自Postman的JSON，当我的应用运行并且我正在“手动”测试时，它可以正常工作：
{
"username":"example",
"password":"password",
"email":"newUser@example.com"
}
运行该测试后堆栈跟踪：
22:20:04.469 [main] DEBUG org.springframework.core.env.StandardEnvironment - Adding [systemProperties] PropertySource with lowest search precedence
22:20:04.474 [main] DEBUG org.springframework.core.env.StandardEnvironment - Adding [systemEnvironment] PropertySource with lowest search precedence
22:20:04.474 [main] DEBUG org.springframework.core.env.StandardEnvironment - Initialized StandardEnvironment with PropertySources [systemProperties,systemEnvironment]
22:20:04.791 [main] DEBUG org.springframework.test.web.servlet.setup.StandaloneMockMvcBuilder$StaticRequestMappingHandlerMapping - Looking for request mappings in application context: org.springframework.test.web.servlet.setup.StubWebApplicationContext@1372ed45
22:20:05.012 [main] DEBUG org.springframework.test.web.servlet.setup.StandaloneMockMvcBuilder$StaticRequestMappingHandlerMapping - 2 request handler methods found on class com.doublemc.controllers.UserController: {public org.springframework.http.ResponseEntity com.doublemc.controllers.UserController.createUser(com.doublemc.domain.User)={[/users],methods=[POST]}, public org.springframework.http.ResponseEntity com.doublemc.controllers.UserController.deleteUser(java.security.Principal)={[/users],methods=[DELETE]}}
22:20:05.021 [main] INFO org.springframework.test.web.servlet.setup.StandaloneMockMvcBuilder$StaticRequestMappingHandlerMapping - Mapped "{[/users],methods=[POST]}" onto public org.springframework.http.ResponseEntity<com.fasterxml.jackson.databind.node.ObjectNode> com.doublemc.controllers.UserController.createUser(com.doublemc.domain.User)
22:20:05.033 [main] INFO org.springframework.test.web.servlet.setup.StandaloneMockMvcBuilder$StaticRequestMappingHandlerMapping - Mapped "{[/users],methods=[DELETE]}" onto public org.springframework.http.ResponseEntity com.doublemc.controllers.UserController.deleteUser(java.security.Principal)
22:20:05.654 [main] DEBUG org.jboss.logging - Logging Provider: org.jboss.logging.Slf4jLoggerProvider
22:20:05.657 [main] INFO org.hibernate.validator.internal.util.Version - HV000001: Hibernate Validator 5.2.4.Final
22:20:05.706 [main] DEBUG org.hibernate.validator.internal.engine.resolver.DefaultTraversableResolver - Found javax.persistence.Persistence on classpath containing 'getPersistenceUtil'. Assuming JPA 2 environment. Trying to instantiate JPA aware TraversableResolver
22:20:05.708 [main] DEBUG org.hibernate.validator.internal.engine.resolver.DefaultTraversableResolver - Instantiated JPA aware TraversableResolver of type org.hibernate.validator.internal.engine.resolver.JPATraversableResolver.
22:20:05.721 [main] DEBUG org.hibernate.validator.internal.engine.ConfigurationImpl - Setting custom MessageInterpolator of type org.springframework.validation.beanvalidation.LocaleContextMessageInterpolator
22:20:05.724 [main] DEBUG org.hibernate.validator.internal.engine.ConfigurationImpl - Setting custom ParameterNameProvider of type com.sun.proxy.$Proxy21
22:20:05.726 [main] DEBUG org.hibernate.validator.internal.xml.ValidationXmlParser - Trying to load META-INF/validation.xml for XML based Validator configuration.
22:20:05.728 [main] DEBUG org.hibernate.validator.internal.xml.ResourceLoaderHelper - Trying to load META-INF/validation.xml via TCCL
22:20:05.729 [main] DEBUG org.hibernate.validator.internal.xml.ResourceLoaderHelper - Trying to load META-INF/validation.xml via Hibernate Validator's class loader
22:20:05.729 [main] DEBUG org.hibernate.validator.internal.xml.ValidationXmlParser - No META-INF/validation.xml found. Using annotation based configuration only.
22:20:05.779 [main] INFO org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter - Looking for @ControllerAdvice: org.springframework.test.web.servlet.setup.StubWebApplicationContext@1372ed45
22:20:05.833 [main] DEBUG org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver - Looking for exception mappings: org.springframework.test.web.servlet.setup.StubWebApplicationContext@1372ed45
22:20:05.864 [main] DEBUG org.springframework.test.web.servlet.TestDispatcherServlet - Initializing servlet ''
22:20:05.877 [main] DEBUG org.springframework.web.context.support.StandardServletEnvironment - Adding [servletConfigInitParams] PropertySource with lowest search precedence
22:20:05.877 [main] DEBUG org.springframework.web.context.support.StandardServletEnvironment - Adding [servletContextInitParams] PropertySource with lowest search precedence
22:20:05.880 [main] DEBUG org.springframework.web.context.support.StandardServletEnvironment - Adding [systemProperties] PropertySource with lowest search precedence
22:20:05.880 [main] DEBUG org.springframework.web.context.support.StandardServletEnvironment - Adding [systemEnvironment] PropertySource with lowest search precedence
22:20:05.880 [main] DEBUG org.springframework.web.context.support.StandardServletEnvironment - Initialized StandardServletEnvironment with PropertySources [servletConfigInitParams,servletContextInitParams,systemProperties,systemEnvironment]
22:20:05.880 [main] INFO org.springframework.mock.web.MockServletContext - Initializing Spring FrameworkServlet ''
22:20:05.881 [main] INFO org.springframework.test.web.servlet.TestDispatcherServlet - FrameworkServlet '': initialization started
22:20:05.883 [main] DEBUG org.springframework.test.web.servlet.TestDispatcherServlet - Unable to locate MultipartResolver with name 'multipartResolver': no multipart request handling provided
22:20:05.884 [main] DEBUG org.springframework.test.web.servlet.TestDispatcherServlet - Using LocaleResolver [org.springframework.web.servlet.i18n.AcceptHeaderLocaleResolver@4e423aa2]
22:20:05.884 [main] DEBUG org.springframework.test.web.servlet.TestDispatcherServlet - Using ThemeResolver [org.springframework.web.servlet.theme.FixedThemeResolver@7fbdb894]
22:20:05.888 [main] DEBUG org.springframework.test.web.servlet.TestDispatcherServlet - Using RequestToViewNameTranslator [org.springframework.web.servlet.view.DefaultRequestToViewNameTranslator@3081f72c]
22:20:05.888 [main] DEBUG org.springframework.test.web.servlet.TestDispatcherServlet - Using FlashMapManager [org.springframework.web.servlet.support.SessionFlashMapManager@3148f668]
22:20:05.888 [main] DEBUG org.springframework.test.web.servlet.TestDispatcherServlet - Published WebApplicationContext of servlet '' as ServletContext attribute with name [org.springframework.web.servlet.FrameworkServlet.CONTEXT.]
22:20:05.888 [main] INFO org.springframework.test.web.servlet.TestDispatcherServlet - FrameworkServlet '': initialization completed in 7 ms
22:20:05.888 [main] DEBUG org.springframework.test.web.servlet.TestDispatcherServlet - Servlet '' configured successfully
22:20:05.928 [main] DEBUG org.springframework.test.web.servlet.TestDispatcherServlet - DispatcherServlet with name '' processing POST request for [/users]
22:20:05.930 [main] DEBUG org.springframework.test.web.servlet.setup.StandaloneMockMvcBuilder$StaticRequestMappingHandlerMapping - Looking up handler method for path /users
22:20:05.934 [main] DEBUG org.springframework.test.web.servlet.setup.StandaloneMockMvcBuilder$StaticRequestMappingHandlerMapping - Returning handler method [public org.springframework.http.ResponseEntity<com.fasterxml.jackson.databind.node.ObjectNode> com.doublemc.controllers.UserController.createUser(com.doublemc.domain.User)]
22:20:06.012 [main] DEBUG org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor - Read [class com.doublemc.domain.User] as "application/json" with [org.springframework.http.converter.json.MappingJackson2HttpMessageConverter@3da30852]
22:20:06.038 [main] DEBUG org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver - Resolving exception from handler [public org.springframework.http.ResponseEntity<com.fasterxml.jackson.databind.node.ObjectNode> com.doublemc.controllers.UserController.createUser(com.doublemc.domain.User)]: java.lang.NullPointerException
22:20:06.040 [main] DEBUG org.springframework.web.servlet.mvc.annotation.ResponseStatusExceptionResolver - Resolving exception from handler [public org.springframework.http.ResponseEntity<com.fasterxml.jackson.databind.node.ObjectNode> com.doublemc.controllers.UserController.createUser(com.doublemc.domain.User)]: java.lang.NullPointerException
22:20:06.041 [main] DEBUG org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver - Resolving exception from handler [public org.springframework.http.ResponseEntity<com.fasterxml.jackson.databind.node.ObjectNode> com.doublemc.controllers.UserController.createUser(com.doublemc.domain.User)]: java.lang.NullPointerException
22:20:06.044 [main] DEBUG org.springframework.test.web.servlet.TestDispatcherServlet - Could not complete request
java.lang.NullPointerException: null
at com.doublemc.controllers.UserController.createUser(UserController.java:37)
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.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:116)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at org.springframework.test.web.servlet.TestDispatcherServlet.service(TestDispatcherServlet.java:65)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.springframework.mock.web.MockFilterChain$ServletFilterProxy.doFilter(MockFilterChain.java:167)
at org.springframework.mock.web.MockFilterChain.doFilter(MockFilterChain.java:134)
at org.springframework.test.web.servlet.MockMvc.perform(MockMvc.java:155)
at com.doublemc.controllers.UserControllerTest.shouldRegisterNewUser(UserControllerTest.java:40)
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.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
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$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:51)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:237)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
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 com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.NullPointerException
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:982)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at org.springframework.test.web.servlet.TestDispatcherServlet.service(TestDispatcherServlet.java:65)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.springframework.mock.web.MockFilterChain$ServletFilterProxy.doFilter(MockFilterChain.java:167)
at org.springframework.mock.web.MockFilterChain.doFilter(MockFilterChain.java:134)
at org.springframework.test.web.servlet.MockMvc.perform(MockMvc.java:155)
at com.doublemc.controllers.UserControllerTest.shouldRegisterNewUser(UserControllerTest.java:40)
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.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
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$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:51)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:237)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
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 com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
Caused by: java.lang.NullPointerException
at com.doublemc.controllers.UserController.createUser(UserController.java:37)
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.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:116)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
... 37 more
Process finished with exit code 255
我发现那些线是最重要的线（至少我是这么认为的）：
22:20:05.928 [main] DEBUG org.springframework.test.web.servlet.TestDispatcherServlet - DispatcherServlet with name '' processing POST request for [/users]
22:20:05.930 [main] DEBUG org.springframework.test.web.servlet.setup.StandaloneMockMvcBuilder$StaticRequestMappingHandlerMapping - Looking up handler method for path /users
22:20:05.934 [main] DEBUG org.springframework.test.web.servlet.setup.StandaloneMockMvcBuilder$StaticRequestMappingHandlerMapping - Returning handler method [public org.springframework.http.ResponseEntity<com.fasterxml.jackson.databind.node.ObjectNode> com.doublemc.controllers.UserController.createUser(com.doublemc.domain.User)]
22:20:06.012 [main] DEBUG org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor - Read [class com.doublemc.domain.User] as "application/json" with [org.springframework.http.converter.json.MappingJackson2HttpMessageConverter@3da30852]
22:20:06.038 [main] DEBUG org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver - Resolving exception from handler [public org.springframework.http.ResponseEntity<com.fasterxml.jackson.databind.node.ObjectNode> com.doublemc.controllers.UserController.createUser(com.doublemc.domain.User)]: java.lang.NullPointerException
22:20:06.040 [main] DEBUG org.springframework.web.servlet.mvc.annotation.ResponseStatusExceptionResolver - Resolving exception from handler [public org.springframework.http.ResponseEntity<com.fasterxml.jackson.databind.node.ObjectNode> com.doublemc.controllers.UserController.createUser(com.doublemc.domain.User)]: java.lang.NullPointerException
22:20:06.041 [main] DEBUG org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver - Resolving exception from handler [public org.springframework.http.ResponseEntity<com.fasterxml.jackson.databind.node.ObjectNode> com.doublemc.controllers.UserController.createUser(com.doublemc.domain.User)]: java.lang.NullPointerException
22:20:06.044 [main] DEBUG org.springframework.test.web.servlet.TestDispatcherServlet - Could not complete request
java.lang.NullPointerException: null