java - FlatFileItemWriter - Writer 必须先打开，然后才能写入

Question

我有一个 SpringBatch 作业，我跳过所有重复的项目写入平面文件。

但是，只要有重复，FlatFileItemWriter 就会引发以下错误：

Writer must be open before it can be written to

以下是 Writer & SkipListener 配置 -

    @Bean(name = "duplicateItemWriter")
    public FlatFileItemWriter<InventoryFileItem> dupItemWriter(){

        return new FlatFileItemWriterBuilder<InventoryFileItem>()
                .name("duplicateItemWriter")
                .resource(new FileSystemResource("duplicateItem.txt"))
                .lineAggregator(new PassThroughLineAggregator<>())
                .append(true)
                .shouldDeleteIfExists(true)
                .build();
    }


public class StepSkipListener implements SkipListener<InventoryFileItem, InventoryItem> {

    private FlatFileItemWriter<InventoryFileItem> skippedItemsWriter;
    
    public StepSkipListener(FlatFileItemWriter<InventoryFileItem> skippedItemsWriter) {
        this.skippedItemsWriter = skippedItemsWriter;
    }
    @Override
    public void onSkipInProcess(InventoryFileItem item, Throwable t) {
        System.out.println(item.getBibNum() + " Process - " + t.getMessage());
        
        try {
            skippedItemsWriter.write(Collections.singletonList(item));
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }

整个 Job 定义如下，我使用的是 SkipListener 中的 duplicateItemWriter。

@Bean(name = "fileLoadJob")
    @Autowired
    public Job fileLoadJob(JobBuilderFactory jobs, StepBuilderFactory steps,
            FlatFileItemReader<inventoryFileItem> fileItemReader,
            CompositeItemProcessor compositeItemProcessor,
            @Qualifier(value = "itemWriter") ItemWriter<InventoryItem> itemWriter,
            StepSkipListener skipListener) {

        return jobs.get("libraryFileLoadJob")
                .start(steps.get("step").<InventoryFileItem, InventoryItem>chunk(chunkSize)
                        .reader(FileItemReader)
                        .processor(compositeItemProcessor)
                        .writer(itemWriter)
                        .faultTolerant()
                        .skip(Exception.class)
                        .skipLimit(Integer.parseInt(skipLimit))
                        .listener(skipListener)
                        .build())
                .build();
    }

我也尝试将所有数据写入 FlatFileItemWriter - 这也不起作用。但是，如果写入数据库，则没有问题。

我使用的 Spring-Batch 版本是 - 4.3.3 我也提到了以下线程：

• 在 Spring 之外对 FlatFileItemWriter 进行单元测试 - “Writer 在写入之前必须打开”异常
• Spring Batch WriterNotOpenException
• FlatfileItemWriter 与 Compositewriter 示例

标签： javaspringspring-batch-admin

Answer 1

这只是粗略的疏忽，我错过了 FlatFileItemWriter 需要一个流。我对提出这个问题感到有些失望，但我发布答案以防万一它对某人有所帮助。

stream(dupItemWriter)解决方案就像在工作定义中添加一个一样简单。

FlatfileItemWriter 与 Compositewriter 示例

@Bean(name = "fileLoadJob")
    @Autowired
    public Job fileLoadJob(JobBuilderFactory jobs, StepBuilderFactory steps,
            FlatFileItemReader<inventoryFileItem> fileItemReader,
            CompositeItemProcessor compositeItemProcessor,
            @Qualifier(value = "itemWriter") ItemWriter<InventoryItem> itemWriter,
@Qualifier(value = "duplicateItemWriter")FlatFileItemWriter<InventoryFileItem> dupItemWriter,
            StepSkipListener skipListener) {

        return jobs.get("libraryFileLoadJob")
                .start(steps.get("step").<InventoryFileItem, InventoryItem>chunk(chunkSize)
                        .reader(FileItemReader)
                        .processor(compositeItemProcessor)
                        .writer(itemWriter)
                        .faultTolerant()
                        .skip(Exception.class)
                        .skipLimit(Integer.parseInt(skipLimit))
                        .listener(skipListener)
                        .stream(dupItemWriter)
                        .build())
                .build();
    }