Mockito RETURNS_DEEP_STUBS 抛出空指针异常

【问题标题】：Mockito RETURNS_DEEP_STUBS throws nullpointer exceptionMockito RETURNS_DEEP_STUBS 抛出空指针异常
【发布时间】：2021-12-28 10:43:45
【问题描述】：

我在模拟 ClientResponseWrapper 类时遇到了一些问题。我已经模拟了它并添加了“RETURNS_DEEP_STUBS”参数以便能够模拟链式调用。我不断收到“NullPointerException”，不知道为什么。 你能帮帮我吗？

代码如下：

package com.service.external_data.application.synchronize_bookings;

import com.service.external_data.domain.BookingUpdateQueueItem;
import com.service.external_data.domain.repository.BookingUpdateQueueRepository;
import com.service.external_data.domain.repository.KeyValueRepository;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.ArgumentCaptor;
import org.mockito.Captor;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.junit.jupiter.MockitoExtension;
import org.springframework.http.HttpStatus;

import java.util.List;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.mockito.Mockito.RETURNS_DEEP_STUBS;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;


@ExtendWith(MockitoExtension.class)
public class Transaction2Test {

    @Mock
    private KeyValueRepository keyValueRepository;

    @Mock
    private BookingUpdateQueueRepository bookingUpdateQueueRepository;;

    @Mock
    private BookingClient bookingClient;

    @Captor
    private ArgumentCaptor<List<BookingUpdateQueueItem>> bookingUpdateQueueItemCaptor;

    @InjectMocks
    private Transaction transaction;

    @Test
    public void testRunSuccessResponse() {
        Integer startIndex = 456;
        when(keyValueRepository.getFromIndex()).thenReturn(startIndex);

        ClientResponseWrapper<BookingUpdateResponse> clientResponse = mock(ClientResponseWrapper.class, RETURNS_DEEP_STUBS);

        BookingUpdateDto bookingUpdateDto = mock(BookingUpdateDto.class);
        when(bookingUpdateDto.getBookingNumber()).thenReturn("12345");

        List<BookingUpdateDto> bookingUpdateDtos = List.of(bookingUpdateDto);

        when(clientResponse.getResponseBody().getData()).thenReturn(bookingUpdateDtos);
        when(clientResponse.getStatusCode()).thenReturn(HttpStatus.OK);

        List<BookingUpdateDto> bookings = mock(List.class);
        BookingUpdateResponse bookingUpdateResponse = mock(BookingUpdateResponse.class);
        when(clientResponse.getResponseBody()).thenReturn(bookingUpdateResponse);
        when(bookingUpdateResponse.getData()).thenReturn(bookings);

        when(bookingClient.requestBookingUpdates(startIndex)).thenReturn(clientResponse);

        Integer nextIndex = 678;
        when(bookingUpdateResponse.getNextFrom()).thenReturn(nextIndex);

        transaction.run();

        verify(bookingUpdateQueueRepository).saveAll(bookingUpdateQueueItemCaptor.capture());

        Integer listSize = bookingUpdateQueueItemCaptor.getValue().size();

        assertEquals(1, listSize);
        verify(keyValueRepository).setFromIndex(nextIndex);
    }
}

例外情况是： java.lang.NullPointerException 在行： "当(clientResponse.getResponseBody().getData()).thenReturn(bookingUpdateDtos);"

完整的堆栈跟踪：

java.lang.NullPointerException
    at com.service.external_data.application.synchronize_bookings.Transaction2Test.testRunSuccessResponse(Transaction2Test.java:60)
    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$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
    at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:149)
    at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:140)
    at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:84)
    at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(ExecutableInvoker.java:115)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke$0(ExecutableInvoker.java:105)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain$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$6(TestMethodTestDescriptor.java:210)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:206)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:131)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:65)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1540)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:143)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1540)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:143)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:108)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:88)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute$0(EngineExecutionOrchestrator.java:54)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:67)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:52)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:96)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:75)
    at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor$CollectAllTestClassesExecutor.processAllTestClasses(JUnitPlatformTestClassProcessor.java:99)
    at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor$CollectAllTestClassesExecutor.access$000(JUnitPlatformTestClassProcessor.java:79)
    at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor.stop(JUnitPlatformTestClassProcessor.java:75)
    at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.stop(SuiteTestClassProcessor.java:61)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
    at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
    at org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:33)
    at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:94)
    at com.sun.proxy.$Proxy5.stop(Unknown Source)
    at org.gradle.api.internal.tasks.testing.worker.TestWorker$3.run(TestWorker.java:193)
    at org.gradle.api.internal.tasks.testing.worker.TestWorker.executeAndMaintainThreadName(TestWorker.java:129)
    at org.gradle.api.internal.tasks.testing.worker.TestWorker.execute(TestWorker.java:100)
    at org.gradle.api.internal.tasks.testing.worker.TestWorker.execute(TestWorker.java:60)
    at org.gradle.process.internal.worker.child.ActionExecutionWorker.execute(ActionExecutionWorker.java:56)
    at org.gradle.process.internal.worker.child.SystemApplicationClassLoaderWorker.call(SystemApplicationClassLoaderWorker.java:133)
    at org.gradle.process.internal.worker.child.SystemApplicationClassLoaderWorker.call(SystemApplicationClassLoaderWorker.java:71)
    at worker.org.gradle.process.internal.worker.GradleWorkerMain.run(GradleWorkerMain.java:69)
    at worker.org.gradle.process.internal.worker.GradleWorkerMain.main(GradleWorkerMain.java:74)

【问题讨论】：

  • 你必须先设置响应体对象。例如 when(clientResponse.getResponseBody()).thenReturn(Data 对象);
  • 但是“RETURNS_DEEP_STUBS”功能不应该处理模拟的所有中间调用吗？
  • 请将完整的堆栈跟踪添加到您的问题中。
  • 您可以查看 Mockito 对干净代码和验证的看法。有一个与之相关的警告。链接：javadoc.io/doc/org.mockito/mockito-core/2.6.9/org/mockito/…
  • ClientResponseWrapper 是你写的一个类，是public 和非final？ （或者它是一个接口？）getResponseBody() 也是public 和非final？ 60号线是哪条线？最后，你为什么嘲笑getResponseBody().getData()，然后用你自己的bookingUpdateResponse代替它？

标签： java unit-testing junit mockito


【解决方案1】：

我能够找到解决问题的方法。正如 Jeff Bowman 所提到的，我在嘲笑“bookingUpdateResponse.getData()”“两次”的响应，我认为因此引发了异常。我能够在没有“RETURNS_DEEP_STUBS”的情况下编写测试（通过模拟中间调用）：

结果：

    @Test
    public void testRunSuccessResponse() {
        Integer startIndex = 456;
        when(keyValueRepository.getFromIndex()).thenReturn(startIndex);

        ClientResponseWrapper<BookingUpdateResponse> clientResponse = mock(ClientResponseWrapper.class);

        BookingUpdateDto bookingUpdateDto = mock(BookingUpdateDto.class);
        when(bookingUpdateDto.getBookingNumber()).thenReturn("12345");

        List<BookingUpdateDto> bookingUpdateDtos = List.of(bookingUpdateDto);

        when(clientResponse.getStatusCode()).thenReturn(HttpStatus.OK);

        BookingUpdateResponse bookingUpdateResponse = mock(BookingUpdateResponse.class);
        when(clientResponse.getResponseBody()).thenReturn(bookingUpdateResponse);
        when(bookingUpdateResponse.getData()).thenReturn(bookingUpdateDtos);

        when(bookingClient.requestBookingUpdates(startIndex)).thenReturn(clientResponse);

        Integer nextIndex = 678;
        when(bookingUpdateResponse.getNextFrom()).thenReturn(nextIndex);

        transaction.run();

        verify(bookingUpdateQueueRepository).saveAll(bookingUpdateQueueItemCaptor.capture());

        Integer listSize = bookingUpdateQueueItemCaptor.getValue().size();

        assertEquals(1, listSize);
        verify(keyValueRepository).setFromIndex(nextIndex);
    }

感谢大家的帮助！

【讨论】：

    猜你喜欢
    • 2020-03-13
    • 1970-01-01
    • 2015-10-07
    • 1970-01-01
    • 1970-01-01
    • 1970-01-01
    • 2020-11-22
    • 2020-08-10
    相关资源
    最近更新 更多
    热门标签
    Java Python linux javascript Mysql C# Docker 算法 前端 SpringBoot Redis Vue spring 设计模式 .net core .net kubernetes c++ 数据库 数据结构 大数据 js 机器学习 微服务 Android Go 程序员 面试 JVM ASP.net core 云原生 人工智能 后端 PHP git CSS golang k8s Nginx Django mybatis 深度学习 多线程 React 架构 devops 爬虫 云计算 Spring Boot LeetCode