Spring批处理项目读取

Question

我正在使用JpaPagingItemReaderBuilder查询一个DB，结果被插入到另一个DB中。

查询返回的结果没有任何问题，但我得到了一个错误与读取器的返回，在处理器中，您可以检查我的编码和错误下面。

有谁能给我一点启示吗？为什么我不能处理结果？

        @Bean
        public Step sampleStep(){

            return stepBuilderFactory.get("sampleStep")
                    .<FCR_HDR,FCR_HDR>chunk(5)
                    .reader(itemReader())
                    .processor(processor())
                    //.writer(i -> i.stream().forEach(j -> System.out.println(j)))
                    //.writer(i -> i.forEach(j -> System.out.println(j)))
                    .writer(jpaItemWriter())
                    .build();
        }

        @Bean
        public Job sampleJob(){
            return jobBuilderFactory.get("sampleJob")
                    .incrementer(new RunIdIncrementer())
                    .start(sampleStep())
                    .build();
        }

        @Bean
        public FcrItemProcessor processor() {
            return new FcrItemProcessor();
        }
        @Bean
        @StepScope
        public JpaPagingItemReader<FCR_HDR> itemReader(/*@Value("${query}") String query*/){

            return new JpaPagingItemReaderBuilder<FCR_HDR>()
                    .name("db2Reader")
                    .entityManagerFactory(localContainerEntityManagerFactoryBean.getObject())
                    .queryString("select f.fcr_ref,f.num_subbills from FCR_HDR f where f.fcr_ref in ('R2G0130185','R2G0128330')")
                    //.queryString(qry)
                    .pageSize(3)
                    .build();
        }


        @Bean
        @StepScope
        public JpaItemWriter jpaItemWriter(){
            JpaItemWriter writer = new JpaItemWriter();
            writer.setEntityManagerFactory(emf);
            return writer;

        }


    }

    public class FcrItemProcessor implements ItemProcessor<FCR_HDR,FCR_HDR> {

    private static final Logger log = LoggerFactory.getLogger(FcrItemProcessor.class);

    @Nullable
    @Override
    public FCR_HDR process(FCR_HDR fcr_hdr) throws Exception {
        final String fcrNo = fcr_hdr.getFcr_ref();
        final String numsubbills = fcr_hdr.getNum_subbills();

        final FCR_HDR transformFcr = new FCR_HDR();

        transformFcr.setFcr_ref(fcrNo);
        transformFcr.setNum_subbills(numsubbills);

        log.info("Converting (" + fcr_hdr + ") into (" + transformFcr + ")");

        return transformFcr;
    }
    }

java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to com.electronicfcr.efcr.model.FCR_HDR

Answer 1

因为您在JPAPagingItemReader中配置了以下查询：

.queryString("select f.fcr_ref,f.num_subbills from FCR_HDR f where f.fcr_ref in ('R2G0130185','R2G0128330')")

查询的格式为JPQL，它将由JPA处理，如果从映射实体中选择某些映射列，JPA将返回Object[]。

将其更改为：

.queryString("select f from FCR_HDR f where f.fcr_ref in ('R2G0130185','R2G0128330')")