unit-testing - Mockito junit 测试不起作用-@mockBean 模拟的 bean 为空
问题描述
我正在尝试 Mockito 进行模拟和单元测试。
尝试使用@MockBean
. 但是 bean 在运行时为空。
正在测试的班级。
@Service
public class UserServiceImpl {
@Autowired
GenericRestClient restClient;
@Autowired
RequestMapper requestMapper;
@Autowired
ResponseMapper responseMapper;
@Override
public List<User> findUsers(RRequest requestBody,
String index) throws HostException {
List<User> users=
requestMapper.mapRequest("test");
// ...doing something
return users;
}
测试类:
import static org.junit.Assert.assertNotNull;
import java.util.ArrayList;
import java.util.List;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.InjectMocks;
import org.mockito.Mockito;
import org.mockito.MockitoAnnotations;
import org.mockito.junit.MockitoJUnitRunner;
import org.springframework.boot.test.mock.mockito.MockBean;
@RunWith(MockitoJUnitRunner.class)
public class UserServiceImplTest {
@MockBean
GenericRestClient restClient;
@MockBean
RequestMapper requestMapper;
@MockBean
ResponseMapper responseMapper;
@InjectMocks
UserServiceImpl userService;
@Before
public void setup() {
MockitoAnnotations.initMocks(this);
}
@Test
public void testFindUsers() {
List<Users> users = null;
Mockito.when(requestMapper.mapRequest("test"))
.thenReturn(users);
assertNull(users);
}
}
错误 :
java.lang.NullPointerException
at test.my.code.UserServiceImplTest.testFindUsers(UserServiceImplTest.java:10)
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.mockito.internal.runners.DefaultInternalRunner$1.run(DefaultInternalRunner.java:79)
at org.mockito.internal.runners.DefaultInternalRunner.run(DefaultInternalRunner.java:85)
at org.mockito.internal.runners.StrictRunner.run(StrictRunner.java:39)
at org.mockito.junit.MockitoJUnitRunner.run(MockitoJUnitRunner.java:163)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:89)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:41)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:541)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:763)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:463)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:209)
我已经调试过,NullPointerException
是因为requestMapper
(使用 MockBean 进行模拟null
。)
这段代码有什么问题?
解决方案
与@abinmichael 不同,我不建议使用 Spring Runner 来运行此测试。你的测试是单元测试,运行Spring(创建应用上下文)是一个非常昂贵的操作,更适合集成测试。
我不是 mockito 专家,但我相信,你应该稍微重构一下,UserServiceImpl
以便依赖项变得可见:
@Service
public class UserServiceImpl {
private final GenericRestClient restClient;
private final RequestMapper requestMapper;
private final ResponseMapper responseMapper;
@Autowired // in recent spring version, this annotation can be omitted
public UserServiceImpl(GenericRestClient restClient, RequestMapper requestMapper, ResponseMapper responseMapper) {
this.restClient = restClient;
this.requestMapper = requestMapper;
this.responseMapper = responseMapper;
}
...
使用这种方法,不再需要@InjectMocks
:
@RunWith(MockitoJUnitRunner.class)
public class UserServiceImplTest {
@Mock
GenericRestClient restClient;
@Mock
RequestMapper requestMapper;
@Mock
ResponseMapper responseMapper;
UserServiceImpl userService;
@Before
public void init() {
userService = new UserServiceImpl(restClient, requestMapper, responseMapper);
}
....
}
如果您坚持使用字段注入,请阅读接受的答案以获取有关如何@InjectMocks
工作的更多信息。也许您没有“私有”访问修饰符,也许您在构造函数注入和字段注入之间有一些混合,并且@InjectMocks
不能同时支持两者
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