“Mock is null in JUnit Test” 可以翻译为 “在JUnit测试中，模拟对象为空”。

huangapple
go评论94阅读模式
英文:

Mock is null in JUnit Test

问题

你运行这个测试时遇到了空指针异常，异常信息表明是因为无法调用com.example.TheConfiguration.getUser()方法，因为this.config是null。

问题的原因在于你的config依赖没有正确注入。在你的测试类AuthenticationTest中，你使用了@Mock注解来模拟TheConfiguration，但这只是模拟对象，并不会真正注入到Authentication类中。因此，在Authentication类的generateAuthentification方法中，当你尝试访问config对象时，它是null。

为了解决这个问题，你需要确保TheConfiguration对象被正确注入到Authentication类中。你可以使用@InjectMocks注解来注入Authentication类中的依赖对象。确保在测试类中使用@InjectMocks注解来注入Authentication类的实例。

另外，检查一下TheConfiguration类是否有正确的@Component注解和@Autowired注解，以便Spring能够正确地注入它。

最后，确保你的测试类和被测试的类都位于正确的包路径下，以便Spring能够扫描到它们并进行注入。

修复这些问题后，你的测试应该能够正常运行而不再抛出空指针异常。

英文:

For test this class:

  1. @Component
  2. @Slf4j
  3. public class Authentication {
  5.     private final RestTemplate restTemplate;
  7.     @Autowired
  8.     private TheConfiguration config;
  10.     public Authentication(RestTemplate restTemplate) {
  11.         this.restTemplate = restTemplate;
  12.     }
  15.     public String generateAuthentification(){
  17.         String plainCreds = config.geUser()+":"+config.getPassword();
  18.         byte[] plainCredsBytes = plainCreds.getBytes();
  19.         byte[] base64CredsBytes = Base64.encodeBase64(plainCredsBytes);
  21.         return new String(base64CredsBytes);
  22.     }
  24. }

I design following test in Junit using Mockito:

  1. import static org.mockito.Mockito.when;
  2. import org.apache.commons.codec.binary.Base64;
  3. import org.junit.jupiter.api.Test;
  4. import org.junit.jupiter.api.extension.ExtendWith;
  5. import org.mockito.InjectMocks;
  6. import org.mockito.Mock;
  7. import org.mockito.junit.jupiter.MockitoExtension;
  8. import org.springframework.web.client.RestTemplate;
  10. import com.example.TheConfiguration;
  12. @ExtendWith(MockitoExtension.class)
  13. class AuthenticationTest {
  15. 	@InjectMocks
  16. 	Authentication authentication;
  18. 	@Mock
  19. 	RestTemplate restTemplate;
  21. 	@Mock
  22. 	TheConfiguration config;
  24. 	@Test
  25. 	void testGenerateAuthentifications() {
  27. 		when(config.getUser()).thenReturn("user");
  28. 		when(config.getPassword()).thenReturn("pass");
  29. 		String plainCreds = config.getUser() + ":" + config.getPassword();
  30. 		System.out.println(plainCreds);
  31. 		byte[] plainCredsBytes = plainCreds.getBytes();
  32. 		byte[] base64CredsBytes = Base64.encodeBase64(plainCredsBytes);
  33. 		String a = new String(base64CredsBytes);
  35. 		assertEquals(authentication.generateAuthentification(),a);
  37. 	}
  39. }

I made other tests with this structure and It works for me. But when I run this test, I have NullPointerException:

Cannot invoke "com.example.TheConfiguration.getUser()" because "this.config" is null

What am I doing wrong?

Edit
Full log:

  1. java.lang.NullPointerException: Cannot invoke "com.example.TheConfiguration.getUser()" because "this.config" is null
  2. at com.example.Authentication.generateAuthentification(Authentication.java:26)
  3. at com.example.AuthenticationTest.testGenerateAuthentifications(AuthenticationTest.java:38)
  4. at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  5. at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
  6. at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  7. at java.base/java.lang.reflect.Method.invoke(Method.java:568)
  8. at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:725)
  9. at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
  10. at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
  11. at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:149)
  12. at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:140)
  13. at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:84)
  14. at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(ExecutableInvoker.java:115)
  15. at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke$0(ExecutableInvoker.java:105)
  16. at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:106)
  17. at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64)
  18. at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45)
  19. at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37)
  20. at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:104)
  21. at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:98)
  22. at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$7(TestMethodTestDescriptor.java:214)
  23. at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
  24. at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:210)
  25. at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:135)
  26. at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:66)
  27. at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:151)
  28. at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
  29. at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)
  30. at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
  31. at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)
  32. at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
  33. at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
  34. at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
  35. at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
  36. at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
  37. at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:155)
  38. at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
  39. at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)
  40. at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
  41. at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)
  42. at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
  43. at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
  44. at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
  45. at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
  46. at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
  47. at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:155)
  48. at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
  49. at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)
  50. at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
  51. at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)
  52. at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
  53. at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
  54. at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
  55. at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:35)
  56. at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
  57. at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:54)
  58. at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:107)
  59. at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:88)
  60. at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute$0(EngineExecutionOrchestrator.java:54)
  61. at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:67)
  62. at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:52)
  63. at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:114)
  64. at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:95)
  65. at org.junit.platform.launcher.core.DefaultLauncherSession$DelegatingLauncher.execute(DefaultLauncherSession.java:91)
  66. at org.junit.platform.launcher.core.SessionPerRequestLauncher.execute(SessionPerRequestLauncher.java:60)
  67. at org.eclipse.jdt.internal.junit5.runner.JUnit5TestReference.run(JUnit5TestReference.java:98)
  68. at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:40)
  69. at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:529)
  70. at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:756)
  71. at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:452)
  72. at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:210)

答案1

得分: 1

尝试添加：

  1. @BeforeMethod
  2. public void initMocks(){
  3.     MockitoAnnotations.openMocks(this);
  4. }

更多细节请参考此链接。

英文:

Try adding :

  1. @BeforeMethod
  2. public void initMocks(){
  3.     MockitoAnnotations.openMocks(this);
  4. }

For more details

huangapple
  • 本文由 发表于 2023年2月16日 16:22:32
  • 转载请务必保留本文链接：https://go.coder-hub.com/75469513.html
  • java
  • junit
  • mocking
  • mockito
匿名

发表评论

匿名网友

:?: :razz: :sad: :evil: :!: :smile: :oops: :grin: :eek: :shock: :???: :cool: :lol: :mad: :twisted: :roll: :wink: :idea: :arrow: :neutral: :cry: :mrgreen:

确定