Spring Batch ItemReader #StepScope null pointer exception - spring

Question

Based on what I was reading around and some other similar questions, by specifying a spring batch component being StepScope means that Spring Batch will use the spring container to instantiate a new instance of that component for each step execution.
In my particular case I have the countryXmlFileToDatabaseStep() which configuration is below and another step which just download a file, delete the existing folder and create a new folder with the xml file.
With the current impl I have, without using the #StepScope annotation on the ItemReader everything works fine, but this is not right, as I need the Spring container to instantiate a new instance of the ItemReader component for each step execution. This way I can delete the Xml file from my C:\ProcessFolder and replace it with the new file on the First Step then go to the next step countryXmlFileToDatabaseStep(). If the XML file name will change I can change the name in the properties file which should be picked up by Spring on the next job run.
Currently I am getting a NULL pointer and no idea why. Below is my Step configuration, including the stack trace.
Configuration
#PropertySource("classpath:application.properties")
public class CountriesListJobConfiguration extends AbstractHarvestService {
private static final String QUERY_INSERT_EOI_MASTER= "INSERT " +
"INTO MASTER(ISTER, MVALUE, MCODE, PROFILEURL, TYPE) " +
"VALUES (?, ?, ?, ?, ?)";
#Value( "${path.folder.master.country}" )
private String countryXmlP;
// This points to my drive C:\\ProcessFolder\\Country_20180715.xml
#Bean
#StepScope
ItemReader<CountryName> countryNameItemReader() {
StaxEventItemReader<CountryName> xmlFileReader = new StaxEventItemReader<>();
xmlFileReader.setResource(new FileSystemResource(countryXmlP));
xmlFileReader.setFragmentRootElementName("CountryName");
Jaxb2Marshaller studentMarshaller = new Jaxb2Marshaller();
studentMarshaller.setClassesToBeBound(CountryName.class);
xmlFileReader.setUnmarshaller(studentMarshaller);
return xmlFileReader;
}
#Bean
ItemProcessor<CountryName, CountryName> countryNameItemProcessor() {
return new CountryItemProcessor();
}
#Bean
ItemWriter<CountryName> countryNameItemWriter(DataSource dataSource, NamedParameterJdbcTemplate jdbcTemplate) {
JdbcBatchItemWriter<CountryName> databaseItemWriter = new JdbcBatchItemWriter<>();
databaseItemWriter.setDataSource(dataSource);
databaseItemWriter.setJdbcTemplate(jdbcTemplate);
databaseItemWriter.setSql(QUERY_INSERT_EOI_MASTER);
ItemPreparedStatementSetter<CountryName> studentPreparedStatementSetter = new CountryItemPreparedStatementSetter();
databaseItemWriter.setItemPreparedStatementSetter(studentPreparedStatementSetter);
return databaseItemWriter;
}
#Bean
Step countryXmlFileToDatabaseStep() {
return stepBuilderFactory.get("countryXmlFileToDatabaseStep")
.<CountryName, CountryName>chunk(10)
.reader(countryNameItemReader())
.processor(countryNameItemProcessor())
.writer(countryNameItemWriter(super.dataSource, super.namedParameterJdbcTemplate))
.build();
}
#Bean
public Flow country() {
FlowBuilder<Flow> flowBuilder = new FlowBuilder<>("country");
flowBuilder.start(countryXmlFileToDatabaseStep())
.end();
return flowBuilder.build();
}
The stacktrace:
java.lang.NullPointerException: null
at org.springframework.batch.item.xml.StaxEventItemReader.moveCursorToNextFragment(StaxEventItemReader.java:151) ~[spring-batch-infrastructure-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.item.xml.StaxEventItemReader.doRead(StaxEventItemReader.java:228) ~[spring-batch-infrastructure-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.item.support.AbstractItemCountingItemStreamItemReader.read(AbstractItemCountingItemStreamItemReader.java:88) ~[spring-batch-infrastructure-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_144]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_144]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_144]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_144]
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:333) ~[spring-aop-4.3.17.RELEASE.jar:4.3.17.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190) ~[spring-aop-4.3.17.RELEASE.jar:4.3.17.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) ~[spring-aop-4.3.17.RELEASE.jar:4.3.17.RELEASE]
at org.springframework.aop.support.DelegatingIntroductionInterceptor.doProceed(DelegatingIntroductionInterceptor.java:133) ~[spring-aop-4.3.17.RELEASE.jar:4.3.17.RELEASE]
at org.springframework.aop.support.DelegatingIntroductionInterceptor.invoke(DelegatingIntroductionInterceptor.java:121) ~[spring-aop-4.3.17.RELEASE.jar:4.3.17.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.17.RELEASE.jar:4.3.17.RELEASE]
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213) ~[spring-aop-4.3.17.RELEASE.jar:4.3.17.RELEASE]
at com.sun.proxy.$Proxy94.read(Unknown Source) ~[na:na]
at org.springframework.batch.core.step.item.SimpleChunkProvider.doRead(SimpleChunkProvider.java:91) ~[spring-batch-core-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.core.step.item.SimpleChunkProvider.read(SimpleChunkProvider.java:157) ~[spring-batch-core-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.core.step.item.SimpleChunkProvider$1.doInIteration(SimpleChunkProvider.java:116) ~[spring-batch-core-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.repeat.support.RepeatTemplate.getNextResult(RepeatTemplate.java:374) ~[spring-batch-infrastructure-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.repeat.support.RepeatTemplate.executeInternal(RepeatTemplate.java:215) ~[spring-batch-infrastructure-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.repeat.support.RepeatTemplate.iterate(RepeatTemplate.java:144) ~[spring-batch-infrastructure-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.core.step.item.SimpleChunkProvider.provide(SimpleChunkProvider.java:110) ~[spring-batch-core-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.core.step.item.ChunkOrientedTasklet.execute(ChunkOrientedTasklet.java:69) ~[spring-batch-core-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.core.step.tasklet.TaskletStep$ChunkTransactionCallback.doInTransaction(TaskletStep.java:406) ~[spring-batch-core-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.core.step.tasklet.TaskletStep$ChunkTransactionCallback.doInTransaction(TaskletStep.java:330) ~[spring-batch-core-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:133) ~[spring-tx-4.3.17.RELEASE.jar:4.3.17.RELEASE]
at org.springframework.batch.core.step.tasklet.TaskletStep$2.doInChunkContext(TaskletStep.java:272) ~[spring-batch-core-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.core.scope.context.StepContextRepeatCallback.doInIteration(StepContextRepeatCallback.java:81) ~[spring-batch-core-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.repeat.support.RepeatTemplate.getNextResult(RepeatTemplate.java:374) ~[spring-batch-infrastructure-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.repeat.support.RepeatTemplate.executeInternal(RepeatTemplate.java:215) ~[spring-batch-infrastructure-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.repeat.support.RepeatTemplate.iterate(RepeatTemplate.java:144) ~[spring-batch-infrastructure-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.core.step.tasklet.TaskletStep.doExecute(TaskletStep.java:257) ~[spring-batch-core-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.core.step.AbstractStep.execute(AbstractStep.java:200) ~[spring-batch-core-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.core.job.SimpleStepHandler.handleStep(SimpleStepHandler.java:148) [spring-batch-core-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.core.job.flow.JobFlowExecutor.executeStep(JobFlowExecutor.java:64) [spring-batch-core-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.core.job.flow.support.state.StepState.handle(StepState.java:67) [spring-batch-core-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.core.job.flow.support.SimpleFlow.resume(SimpleFlow.java:169) [spring-batch-core-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.core.job.flow.support.SimpleFlow.start(SimpleFlow.java:144) [spring-batch-core-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.core.job.flow.support.state.SplitState$1.call(SplitState.java:93) [spring-batch-core-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.springframework.batch.core.job.flow.support.state.SplitState$1.call(SplitState.java:90) [spring-batch-core-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at java.util.concurrent.FutureTask.run$$$capture(FutureTask.java:266) [na:1.8.0_144]
at java.util.concurrent.FutureTask.run(FutureTask.java) [na:1.8.0_144]
at java.lang.Thread.run(Thread.java:748) [na:1.8.0_144]