java – Spring Batch：org.springframework.batch.item.ReaderNot

我读了相关的问题,但解决方案对我来说并不奏效.

我得到了org.springframework.batch.item.ReaderNotOpenException：读者必须打开才能读取异常.

以下是我的配置：

@Bean
@StepScope
public ItemReader<Player> reader(@Value("#{jobParameters[inputZipfile]}") String inputZipfile) {
                final String [] header = { .. this part omitted for brevity ... };
                FlatFileItemReader<Player> reader = new FlatFileItemReader<Player>();


                System.out.println("\t\t\t\t\t"+inputZipfile);

                reader.setResource(new ClassPathResource(inputZipfile));
                reader.setLineMapper(new DefaultLineMapper<Player>() {{
                    setLineTokenizer(new DelimitedLineTokenizer() {{
                        setNames( header );
                    }});
                    setFieldSetMapper(new BeanWrapperFieldSetMapper<Player>() {{
                        setTargetType(Player.class);
                    }});
                }});
                reader.setComments( header );
                return reader;
}

@Bean
@StepScope
public ItemProcessor<Player,PlayersStats> processor(@Value("#{jobParameters[statType]}") String statType,@Value("#{jobParameters[season]}") String season){
                PlayersStatsProcessor psp = new PlayersStatsProcessor();
                psp.setStatisticType( StatisticType.valueOf(statType) );
                psp.setSeason( season );
                return psp;
}


@Bean
@StepScope
public ItemWriter<PlayersStats> writer(){
            return new CustomWriter();
}


@Bean
public Job generateStatisticsJob() {

        return this.jobs.get("generateStatisticsJob")
                .incrementer(new RunIdIncrementer())
                .start(processPlayerStats())
                //.end()
                .build();
}

@Bean
public Step processPlayerStats() {
           return this.steps.get("processPlayerStats")        
                        .<Player,PlayersStats> chunk(10)
                        .reader(reader(null))
                        .processor(processor(null,null))
                        .writer(writer())
                        .build();
}

inputZipFile变量设置正确,文件存在于驱动器上.
我检查了FlatFileItemReader代码,并且ReaderNotOpenException发生在读者类的读者成员未设置时.读者成员设置为doOpen方法.
看起来doOpen不被调用.问题是为什么？

解决方法

当我将读取器bean的返回类型从Item更改为FlatFileItemReader时,问题消失了.我仍然不清楚为什么这是一个问题,因为chunk().reader()接受ItemReader作为输入.我假设有一些AOP魔术在引擎盖下,FlatFileReader init和返回类型匹配.