jobLauncherTestUtils 的 NullPointerException 可能是什么原因？ (Spring 批次)

Question

我有一个带步骤的作业，当我尝试使用 JobLauncherTestUtils 测试该作业时，出现以下异常：

java.lang.NullPointerException
at io.spring.cdrreader.CdrReaderApplicationTests.testJob(CdrReaderApplicationTests.java:32)
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.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.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.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access[=11=]0(ParentRunner.java:58)
at org.junit.runners.ParentRunner.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.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:230)
at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:58)

我在网上搜索并尝试了很多方法来解决这个问题，但这些都没有用。

测试class:

@ExtendWith(SpringExtension.class)
@SpringBatchTest
@ContextConfiguration(classes = {Config.class})
public class CdrReaderApplicationTests {

@Autowired
private JobLauncherTestUtils jobLauncherTestUtils;

@Test
public void testJob() throws Exception {

    JobParameters jobParameters =
            jobLauncherTestUtils.getUniqueJobParameters();

    JobExecution jobExecution =
            jobLauncherTestUtils.launchJob(jobParameters);

    Assert.assertEquals(ExitStatus.COMPLETED,
            jobExecution.getExitStatus());
}

}

使用配置中的作业初始化 JobLauncherTestUtils class：

    @Bean
    public JobLauncherTestUtils getJobLauncherTestUtils() {

    return new JobLauncherTestUtils() {
        @Override
        @Autowired
        public void setJob(@Qualifier("demoJob") Job job) {
            super.setJob(job);
        }
    };
}

Answer 1

你是运行作为 JUnit 4 测试的测试（参见 Stacktrace com.intellij.junit4.JUnit4IdeaTestRunner），但是你的测试用 @ExtendWith(SpringExtension.class) 注释，这是 JUnit 5 API.

这导致 Spring 测试扩展（如 @SpringBatchTest）未被提取，因为 Spring extension/runner 未注册。这会导致 NPE（@Autowired 功能不起作用）。

因此，您要么将其更改为 @RunWith(SpringRunner.class)，要么将测试作为 JUnit 5 测试开始。

JUnit 4 测试示例：

@RunWith(SpringRunner.class)
@SpringBatchTest
@ContextConfiguration(classes = {Config.class})
public class CdrReaderApplicationTests {
   // ...
}

jobLauncherTestUtils 的 NullPointerException 可能是什么原因？ (Spring 批次)

What might be a reason for NullPointerException of jobLauncherTestUtils? (Spring Batch)

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