从 FlatFileItemReader LineMapper 访问平面文件的名称 [英] Accessing name of flat file from FlatFileItemReader LineMapper

问题描述

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

I have a need to be able to access the name of the flat file that the current line being read is from. We are porting an application and some processes that are currently in place require this information.

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;
}

InvoiceLineMapper:

InvoiceLineMapper:

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 委托给 invoiceFlatFileItemReader() :

I am delegating to the invoiceFlatFileItemReader() via a MultiResourceItemReader:

@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;
}

如何获取资源的名称沿链向下传递到我可以在 InvoiceLineMapper 类中访问它的位置并将其添加到模型中(稍后使用 <代码>RepositoryItemWriter)?

How can I get the name of the resource passed down the chain to where I can access it in the InvoiceLineMapper class and add it to the model (which later gets persisted with a RepositoryItemWriter)?

推荐答案

这是我最终要做的，只是将 MultiItemResourceReader 向下传递，以便我可以调用 getCurrentResource() 在行映射器中:

Here's what I ended up doing, just passing the MultiItemResourceReader down the chain so that I could call getCurrentResource() in the line mapper:

@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:

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;
    }
}

这篇关于从 FlatFileItemReader LineMapper 访问平面文件的名称的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！