java - 从 FlatFileItemReader LineMapper 访问平面文件的名称

Question

我需要能够访问正在读取的当前行所在的平面文件的名称。我们正在移植一个应用程序，目前的一些流程需要此信息。

这是我当前的配置:

private FlatFileItemReader<Invoice> invoiceFlatFileItemReader() throws Exception {
    FlatFileItemReader<Invoice> reader = new FlatFileItemReader<>();
    reader.setLinesToSkip(1); // header row
    reader.setLineMapper(new InvoiceLineMapper());
    reader.afterPropertiesSet();

    return reader;
}

发票行映射器:

public class InvoiceLineMapper implements LineMapper<Invoice> {

    @Override
    public Invoice mapLine(String line, int lineNumber) throws Exception {
        String[] fields = line.split(",");
        ArrayList<String> fieldList = new ArrayList<>();

        for (int i = 0; i < fields.length; i++) {
            fieldList.add(fields[i].replaceAll("\"", "");
        }

        Invoice invoice = new Invoice();

        invoice.setCustomerNumber(Integer.parseInt(fieldList.get(0));
        invoice.setCustomerName(fieldList.get(1));

        // set other things and stuff...

        //Need to be able to set the file name on the model here
        invoice.setFileName(theFileName);
    }
}

我通过 MultiResourceItemReader 委托(delegate)给 invoiceFlatFileItemReader():

@Bean
public ItemReader<Invoice> invoiceItemReader() throws Exception {
    ResourcePatternResolver resolver = new PathMatchingResourcePatterResolver(this.getClass().getClassLoader());

    // currently being loaded from the classpath, eventually will be read from S3...that comes later
    Resource[] resources = resolver.getResources("classpath*:**/InvoiceList*.csv*"); 

    MultiResourceItemReader<Invoice> reader = new MultiResourceItemReader<>();
    reader.setResources(resources);
    reader.setDelegate(invoiceFlatFileItemReader());

    return reader;
}

我怎样才能获得资源的名称沿着链传递到我可以在 InvoiceLineMapper 类中访问它的位置并将其添加到模型(稍后通过 RepositoryItemWriter)?

Answer 1

这是我最后做的，只是将 MultiItemResourceReader 传递到链中，以便我可以在行映射器中调用 getCurrentResource():

@Bean
public ItemReader<Invoice> invoiceItemReader() throws Exception {
    ResourcePatternResolver resolver = new PathMatchingResourcePatterResolver(this.getClass().getClassLoader());

    // currently being loaded from the classpath, eventually will be read from S3...that comes later
    Resource[] resources = resolver.getResources("classpath*:**/InvoiceList*.csv*"); 

    MultiResourceItemReader<Invoice> reader = new MultiResourceItemReader<>();
    reader.setResources(resources);
    reader.setDelegate(invoiceFlatFileItemReader(reader));

    return reader;
}

private FlatFileItemReader<Invoice> invoiceFlatFileItemReader(MultiResourceItemReader delegator) throws Exception {
    FlatFileItemReader<Invoice> reader = new FlatFileItemReader<>();
    reader.setLinesToSkip(1); // header row
    reader.setLineMapper(new InvoiceLineMapper(delegator));
    reader.afterPropertiesSet();

    return reader;
}

然后在 InvoiceLineMapper 中:

public class InvoiceLineMapper implements LineMapper<Invoice> {

    private MultiResourceItemReader delegator;

    public InvoiceLineMapper(MultiResourceItemReader delegator) {
         this.delegator = delegator;
    }

    @Override
    public Invoice mapLine(String line, int lineNumber) throws Exception {
        String[] fields = line.split(",");
        ArrayList<String> fieldList = new ArrayList<>();

        for (int i = 0; i < fields.length; i++) {
            fieldList.add(fields[i].replaceAll("\"", "");
        }

        Invoice invoice = new Invoice();

        invoice.setCustomerNumber(Integer.parseInt(fieldList.get(0));
        invoice.setCustomerName(fieldList.get(1));

        // set other things and stuff...

        Resource currentResource = delegator.getCurrentResource();
        String[] fileName = currentResource.getFilename().split("/");

        invoice.setFileName(filename[filename.length - 1]);

        return invoice;
    }
}