Spring batch 中分区partitioner，使用异步线程怎么使用Jd?400报错

如下是报错信息：

org.springframework.batch.item.ItemStreamException: Failed to initialize the reader
    at org.springframework.batch.item.support.AbstractItemCountingItemStreamItemReader.open(AbstractItemCountingItemStreamItemReader.java:147)
    at org.springframework.batch.item.database.JdbcPagingItemReader.open(JdbcPagingItemReader.java:260)
    at org.springframework.batch.item.support.CompositeItemStream.open(CompositeItemStream.java:96)
    at org.springframework.batch.core.step.tasklet.TaskletStep.open(TaskletStep.java:310)
    at org.springframework.batch.core.step.AbstractStep.execute(AbstractStep.java:197)
    at org.springframework.batch.core.partition.support.TaskExecutorPartitionHandler$1.call(TaskExecutorPartitionHandler.java:139)
    at org.springframework.batch.core.partition.support.TaskExecutorPartitionHandler$1.call(TaskExecutorPartitionHandler.java:136)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.IllegalStateException: Cannot open an already opened ItemReader, call close first
    at org.springframework.util.Assert.state(Assert.java:70)
    at org.springframework.batch.item.database.AbstractPagingItemReader.doOpen(AbstractPagingItemReader.java:133)
    at org.springframework.batch.item.support.AbstractItemCountingItemStreamItemReader.open(AbstractItemCountingItemStreamItemReader.java:144)

代码配置：参考网上的示例是可以使用异步线程的。

示例网址：http://blog.csdn.net/weiyanghuadi/article/details/9618389

@Bean(name = "partitionerJob")
    public Job partitionerJob() {
        return jobBuilderFactory.get("partitionerJob")
                .incrementer(new RunIdIncrementer())
                .start(partitionerStepMaster())
                .build();
    }


    @Bean(name = "partitionerStepMaster")
    public Step partitionerStepMaster(){
        return stepBuilderFactory.get("partitionerStepMaster")
                .partitioner("rangePartitioner",rangePartitioner)
               // .partitionHandler(partitionHandler())
                .step(partitionerStepSlave())
                .gridSize(5)
                .taskExecutor(new SimpleAsyncTaskExecutor())  //异步线程 就会报错，
                .build();
    }

    @Bean
    public PartitionHandler partitionHandler() {
        TaskExecutorPartitionHandler retVal = new TaskExecutorPartitionHandler();
        retVal.setTaskExecutor(new SimpleAsyncTaskExecutor());
        retVal.setStep(partitionerStepSlave());
        retVal.setGridSize(5);
        return retVal;
    }

    @Bean(name = "partitionerStepSlave")
    public Step partitionerStepSlave(){
        return stepBuilderFactory.get("partitionerStepSlave")
                //.tasklet(partitionerStepSlaveTasklet())
                .<RepayOrderInfo, RepayOrderInfo> chunk(100)
                .reader(partitionerStepSlaveReader())  //继承JdbcPagingItemReader
                .processor(partitionerStepSlaveProcessor())
                .build();
    }