Spring Batch: Getting step context in processor for partitioned step - spring-batch

Question

I'm developing a Spring Batch job that processes multiple input files in parallel using a MultiResourcePartitioner. In the ItemProcessor I need to get the number of records in the current input file. I get the current file name from the step context and read the number of lines in the file:
StepSynchronizationManager.register(stepExecution);
StepContext stepContext = StepSynchronizationManager.getContext();
StepSynchronizationManager.close();
log.trace("stepContext: " + stepContext.getStepExecution().getExecutionContext().entrySet().toString());
...
UrlResource currentFile = new UrlResource(stepContext.getStepExecution().getExecutionContext().getString("fileName"));
This all seems to work but I'm getting exceptions when accessing the step context from the processor threads:
2013-05-15 11:44:35,178 DEBUG [org.springframework.batch.core.step.tasklet.TaskletStep] <taskExecutor-3> - Rollback for RuntimeException: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'scopedTarget.processor': Scope 'step' is not active for the current thread; consider defining a scoped proxy for this bean if you intend to refer to it from a singleton; nested exception is java.lang.IllegalStateException: No context holder available for step scope
2013-05-15 11:44:35,194 DEBUG [org.springframework.jdbc.datasource.DataSourceUtils] <taskExecutor-3> - Returning JDBC Connection to DataSource
2013-05-15 11:44:35,194 DEBUG [org.springframework.batch.repeat.support.RepeatTemplate] <taskExecutor-3> - Handling exception: org.springframework.beans.factory.BeanCreationException, caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'scopedTarget.processor': Scope 'step' is not active for the current thread; consider defining a scoped proxy for this bean if you intend to refer to it from a singleton; nested exception is java.lang.IllegalStateException: No context holder available for step scope
2013-05-15 11:44:35,194 DEBUG [org.springframework.batch.repeat.support.RepeatTemplate] <taskExecutor-3> - Handling fatal exception explicitly (rethrowing first of 1): org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'scopedTarget.processor': Scope 'step' is not active for the current thread; consider defining a scoped proxy for this bean if you intend to refer to it from a singleton; nested exception is java.lang.IllegalStateException: No context holder available for step scope
2013-05-15 11:44:35,210 ERROR [org.springframework.batch.core.step.AbstractStep] <taskExecutor-3> - Encountered an error executing the step
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'scopedTarget.processor': Scope 'step' is not active for the current thread; consider defining a scoped proxy for this bean if you intend to refer to it from a singleton; nested exception is java.lang.IllegalStateException: No context holder available for step scope
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:341)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:192)
at org.springframework.aop.target.SimpleBeanTargetSource.getTarget(SimpleBeanTargetSource.java:33)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:182)
at $Proxy14.process(Unknown Source)
at org.springframework.batch.core.step.item.SimpleChunkProcessor.doProcess(SimpleChunkProcessor.java:125)
at org.springframework.batch.core.step.item.SimpleChunkProcessor.transform(SimpleChunkProcessor.java:291)
at org.springframework.batch.core.step.item.SimpleChunkProcessor.process(SimpleChunkProcessor.java:190)
at org.springframework.batch.core.step.item.ChunkOrientedTasklet.execute(ChunkOrientedTasklet.java:74)
at org.springframework.batch.core.step.tasklet.TaskletStep$ChunkTransactionCallback.doInTransaction(TaskletStep.java:386)
at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:130)
at org.springframework.batch.core.step.tasklet.TaskletStep$2.doInChunkContext(TaskletStep.java:264)
at org.springframework.batch.core.scope.context.StepContextRepeatCallback.doInIteration(StepContextRepeatCallback.java:76)
at org.springframework.batch.repeat.support.RepeatTemplate.getNextResult(RepeatTemplate.java:367)
at org.springframework.batch.repeat.support.RepeatTemplate.executeInternal(RepeatTemplate.java:214)
at org.springframework.batch.repeat.support.RepeatTemplate.iterate(RepeatTemplate.java:143)
at org.springframework.batch.core.step.tasklet.TaskletStep.doExecute(TaskletStep.java:250)
at org.springframework.batch.core.step.AbstractStep.execute(AbstractStep.java:195)
at org.springframework.batch.core.partition.support.TaskExecutorPartitionHandler$1.call(TaskExecutorPartitionHandler.java:120)
at org.springframework.batch.core.partition.support.TaskExecutorPartitionHandler$1.call(TaskExecutorPartitionHandler.java:118)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)
Caused by: java.lang.IllegalStateException: No context holder available for step scope
at org.springframework.batch.core.scope.StepScope.getContext(StepScope.java:197)
at org.springframework.batch.core.scope.StepScope.get(StepScope.java:139)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:327)
... 24 more
Is there a way to get the current input file name from the processor of a partitioned job?
Here is the relevant config:
<batch:job id="acct">
<batch:step id="init" parent="abstractStep" next="processStep">
<batch:tasklet ref="fileDeleteTasklet" />
</batch:step>
<batch:step id="processStep">
<batch:partition step="processInput" partitioner="partitioner">
<batch:handler grid-size="2" task-executor="taskExecutor" />
</batch:partition>
</batch:step>
</batch:job>
<batch:step id="processInput">
<batch:tasklet>
<batch:chunk reader="reader" processor="processor" writer="writer" commit-interval="3">
<batch:streams>
<batch:stream ref="reader"/>
<batch:stream ref="flatFileItemWriter"/>
</batch:streams>
</batch:chunk>
</batch:tasklet>
</batch:step>
<bean id="partitioner" class="org.springframework.batch.core.partition.support.MultiResourcePartitioner" scope="step">
<property name="keyName" value="fileName"/>
<property name="resources" value="file:#{jobParameters['inputFilePattern']}"/>
</bean>
<bean id="taskExecutor" class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor">
<property name="corePoolSize" value="5"/>
<property name="maxPoolSize" value="5"/>
</bean>
<bean id="reader" class="org.springframework.batch.item.file.FlatFileItemReader" scope="step">
<property name="resource" value="#{stepExecutionContext[fileName]}" />
<property name="lineMapper">
<bean class="org.springframework.batch.item.file.mapping.DefaultLineMapper">
<property name="lineTokenizer">
<bean class="org.springframework.batch.item.file.transform.FixedLengthTokenizer">
<property name="names" value="recordType,reserved,aCode,bCode,acctNumber,idType,cCode" />
<property name="columns" value="1,2,3-6,7-9,10-15,16,17-19" />
<property name="strict" value="false" />
</bean>
</property>
<property name="fieldSetMapper">
<bean class="com.example.batch.acct.AcctInputFieldSetMapper" />
</property>
</bean>
</property>
</bean>
<bean id="processor" class="com.example.batch.acct.AcctProcessor" scope="step">
<property name="soapClient" ref="soapClient" />
<property name="maxNumIds" value="${batch.soap.numberOfIds}" />
<aop:scoped-proxy />
</bean>

Answer 1

Answered on the Spring Batch forum:
The ItemProcessor interface does not expose a way to access the
StepContext, so you need to inject it yourself:
<bean id="itemProcessor" class="com.myApp.MyItemProcessor" scope="step">
<property name="stepContext" value="#{stepExecutionContext}"/>
</bean>
Assuming your processor class has an exposed property named
stepContext.
-- Michael Minella, Spring Batch Lead

Answer 2

<bean id="itemProcessor" class="com.myApp.MyItemProcessor" scope="step">
<property name="stepContext" value="#{stepExecutionContext}"/>
</bean>
In this case when stepContex is a type of org.springframework.batch.core.scope.context.StepContext, how suggests name of this property, I am getting exceptions:
org.springframework.beans.factory.BeanCreationException: Error
creating bean with name
'scopedTarget.itemProcessor' defined in
class path resource [META-INF/jobs/Job.xml]:
Initialization of bean failed; nested exception is
org.springframework.beans.ConversionNotSupportedException: Failed to
convert property value of type 'java.util.Collections$UnmodifiableMap'
to required type
'org.springframework.batch.core.scope.context.StepContext' for
property 'stepContext'; nested exception is
java.lang.IllegalStateException: Cannot convert value of type
'java.util.Collections$UnmodifiableMap' to required type
'org.springframework.batch.core.scope.context.StepContext' for
property 'stepContext': no matching editors or conversion strategy
found
I needed to access jobExecutionId inside ItemProcessor, so I have changed this configuration to:
<bean id="itemProcessor" class="com.myApp.MyItemProcessor" scope="step">
<property name="stepExecution" value="#{stepExecution}"/>
</bean>
Property "stepExecution" is a type org.springframework.batch.core.StepExecution