使用拆分批处理处理处理零记录时出错：mule esb

使用拆分0条记录时出错..使用一条记录或多条记录可以正常工作 但是，如果没有包含split的记录，则会给出错误消息 我犯了这个错误

org.mule.api.MessagingException: Object "java.lang.String" not of correct type. It must be of type "{interface java.lang.Iterable,interface java.util.Iterator,interface org.mule.routing.MessageSequence,interface java.util.Collection}" (java.lang.IllegalArgumentException) (com.mulesoft.module.batch.exception.BatchException). Message payload is of type: String at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:32) at org.mule.execution.MessageProcessorNotificationExecutionInterceptor.execute(MessageProcessorNotificationExecutionInterceptor.java:107) at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:44) at org.mule.processor.BlockingProcessorExecutor.executeNext(BlockingProcessorExecutor.java:88) at org.mule.processor.BlockingProcessorExecutor.execute(BlockingProcessorExecutor.java:59) at org.mule.processor.chain.DefaultMessageProcessorChain.doProcess(DefaultMessageProcessorChain.java:80)

我的流程如下

 <batch:job name="testBatch"> 
        <batch:input> 
            <component class="org.test.d1.Find" doc:name="Java"/> 
            <file:outbound-endpoint path="test" outputPattern="test.xml" responseTimeout="10000" doc:name="File"/> 

            <logger message="COUNT -&gt; #[xpath('fn:count(//po:Account)')]" level="INFO" doc:name="Logger"/> 
            <expression-filter expression="#[xpath('fn:count(//po:Account)')!=0.0]" doc:name="Expression"/> 
            <splitter evaluator="xpath" expression="//po:Account" doc:name="Splitter"/> 
            <collection-aggregator failOnTimeout="true" doc:name="Collection Aggregator"/> 
        </batch:input> 
        <batch:process-records> 
            <batch:step name="Batch_Step"> 
            </batch:step> 
        </batch:process-records> 
        <batch:on-complete> 
            <logger level="INFO" doc:name="Logger"/> 
            <set-payload value="Total Record : #[payload.totalRecords]  fail Records : #[payload.failedRecords]  successfull records :#[payload.successfulRecords +'\n'] " doc:name="Set Payload"/> 

        </batch:on-complete> 
    </batch:job>

---

请帮我解决这个错误。感谢

异常，它自己说您得到了一个字符串作为导致问题的拆分器组件的输入

确保为拆分器组件提供了一个可迭代的对象