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

Question

I have a job with a step and when I attempt to test this job with JobLauncherTestUtils, I get the following exception:
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$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.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$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.junit.IdeaTestRunner$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)
I have searched on net and tried many ways to solve this problem but these did not work.
Test 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());
}
}
Initialization of JobLauncherTestUtils with a job in config class:
#Bean
public JobLauncherTestUtils getJobLauncherTestUtils() {
return new JobLauncherTestUtils() {
#Override
#Autowired
public void setJob(#Qualifier("demoJob") Job job) {
super.setJob(job);
}
};
}

Answer 1

You are running the test as JUnit 4 test (see Stacktrace com.intellij.junit4.JUnit4IdeaTestRunner), however your test is annotated with #ExtendWith(SpringExtension.class), which is JUnit 5 API.
This leads to Spring testing extensions (like #SpringBatchTest) not getting picked up, because the Spring extension/runner is not registered. This results in the NPE (#Autowired functionality doesnt work).
So you either change this to #RunWith(SpringRunner.class) or you start the test as JUnit 5 test.
Example as JUnit 4 Test:
#RunWith(SpringRunner.class)
#SpringBatchTest
#ContextConfiguration(classes = {Config.class})
public class CdrReaderApplicationTests {
// ...
}