如何用Mockito或OOTB API Mock Spring Batch作业编写测试用例？

老哥，你当前的测试会执行真实作业，本质原因是@SpringBatchTest会自动配置批处理相关的测试组件（比如JobLauncherTestUtils），再加上@SpringBootTest会启动完整的Spring上下文，这就把你的真实Job和Step都实例化加载进来了，自然会触发真实的批处理流程。

下面给你两种可行的方案，既有Spring Boot自带的开箱即用方式，也有用Mockito实现的方法：

方案一：用Spring Boot的@MockBean替换真实Job #

Spring Boot的@MockBean注解可以轻松把Spring容器里的真实Job替换成Mock实例，这样JobLauncherTestUtils调用的就是Mock的Job，完全不会触发真实执行。

修改后的测试代码如下：

@SpringBatchTest
@SpringBootTest
@RunWith(SpringRunner.class)
public class JobTest {
    @Autowired
    private JobLauncherTestUtils jobLauncherTestUtils;
    
    // 用@MockBean替换容器中的真实Job，这里替换成你项目里实际的Job类名
    @MockBean
    private Job yourActualJob;

    @Before
    public void setUp() throws Exception {
        // 用Spring Batch自带的工具类创建模拟的JobExecution
        JobExecution mockJobExecution = MetaDataInstanceFactory.createJobExecution();
        mockJobExecution.setStatus(BatchStatus.COMPLETED);
        
        // 模拟StepExecution的结果
        StepExecution mockStepExecution = MetaDataInstanceFactory.createStepExecution();
        mockStepExecution.setStatus(BatchStatus.COMPLETED);
        mockJobExecution.addStepExecution(mockStepExecution);
        
        // 让Mock Job返回我们模拟好的执行结果
        when(yourActualJob.execute(any(JobParameters.class))).thenReturn(mockJobExecution);
    }

    @Test
    public void testJobCompletion() throws Exception {
        JobExecution jobExecution = jobLauncherTestUtils.launchJob();
        assertEquals(BatchStatus.COMPLETED, jobExecution.getStatus());
        
        StepExecution stepExecution = jobExecution.getStepExecutions().iterator().next();
        assertEquals(BatchStatus.COMPLETED, stepExecution.getStatus());
    }
}

方案二：手动配置测试组件，避免加载完整批处理上下文 #

如果你不想加载完整的Spring Batch上下文，可以去掉@SpringBatchTest，手动创建JobLauncherTestUtils并注入Mock的Job和JobLauncher：

@SpringBootTest(classes = {TestConfig.class})
@RunWith(SpringRunner.class)
public class JobTest {
    @Autowired
    private JobLauncherTestUtils jobLauncherTestUtils;

    // 内部配置类，只加载测试需要的组件
    @Configuration
    static class TestConfig {
        @Bean
        public JobLauncher jobLauncher() {
            return mock(JobLauncher.class);
        }

        @Bean
        public Job yourActualJob() {
            return mock(Job.class);
        }

        @Bean
        public JobLauncherTestUtils jobLauncherTestUtils() throws Exception {
            JobLauncherTestUtils testUtils = new JobLauncherTestUtils();
            testUtils.setJob(yourActualJob());
            testUtils.setJobLauncher(jobLauncher());
            return testUtils;
        }
    }

    @Before
    public void setUp() throws Exception {
        JobExecution mockJobExecution = MetaDataInstanceFactory.createJobExecution();
        mockJobExecution.setStatus(BatchStatus.COMPLETED);
        StepExecution mockStepExecution = MetaDataInstanceFactory.createStepExecution();
        mockStepExecution.setStatus(BatchStatus.COMPLETED);
        mockJobExecution.addStepExecution(mockStepExecution);
        
        // 模拟JobLauncher的launch方法返回我们预设的结果
        when(jobLauncherTestUtils.getJobLauncher().launch(any(Job.class), any(JobParameters.class)))
                .thenReturn(mockJobExecution);
    }

    @Test
    public void testJobCompletion() throws Exception {
        JobExecution jobExecution = jobLauncherTestUtils.launchJob();
        assertEquals(BatchStatus.COMPLETED, jobExecution.getStatus());
        StepExecution stepExecution = jobExecution.getStepExecutions().iterator().next();
        assertEquals(BatchStatus.COMPLETED, stepExecution.getStatus());
    }
}

额外小提示 #

• 两种方案的核心都是把真实的Job/JobLauncher换成Mock实例，从根源上避免触发真实批处理逻辑。
• MetaDataInstanceFactory是Spring Batch官方提供的工具类，能快速创建模拟的JobExecution和StepExecution，省得你手动去设置一堆属性。
• 如果你还想验证Job是否被正确调用，可以加一句verify(yourActualJob).execute(any(JobParameters.class))，这样就能确认Mock的Job确实被触发了。

内容的提问来源于stack exchange，提问作者Jeff Cook