Spring-Batch:将对象写入固定长度的行吗? [英] Spring-Batch: Writing objects to lines with fixed length?

问题描述

Spring-Batch提供了类FixedLengthTokenizer，该类可以轻松地将单行的不同偏移量读取到对象的文件中.从而从固定长度的某些范围中提取每个字段的内容:

Spring-Batch provides the class FixedLengthTokenizer which makes it easy to read different offsets of a single line into the fileds of an object. Whereby the content of each field is extracted from certain ranges with fixed length:

FixedLengthTokenizer tokenizer = new FixedLengthTokenizer();
String[] names = {"A", "B", "C", "D"};
tokenizer.setNames(names);
Range[] ranges = {new Range(1, 4), new Range(5, 12), new Range(13, 14), new Range(15, 15)};
tokenizer.setColumns(ranges);

我想完全相反.我想将一个对象写入平面文件，从而将不同的字段以固定的长度写入文件. Spring-Batch提供了接口org.springframework.batch.item.file.transform.LineAggregator，用于将线映射到对象.但是我想知道为什么没有FixedLengthLineAggregator这样做吗?

I want to do the exact oposite. I want to write an Object into a flat file whereby the different fields should be written into the file with fixed lengths. Spring-Batch provides the interface org.springframework.batch.item.file.transform.LineAggregator for mapping lines to objects. But I'm wondering why there is no FixedLengthLineAggregator for doing that?

在Spring-Batch中，将对象写入行以使字段具有固定长度的正确方法是什么?

What's the right way in Spring-Batch to write objects to lines whereby the fields have a fixed length?

推荐答案

正如@canillas在其评论中指出的那样，管理此问题的方法将是通过Spring Batch的FormatterLineAggregator.使用String.format的格式功能，可以使您以独立于JVM和独立于框架的标准方式生成固定长度的记录.

As @canillas noted in their comment, the way to manage this would be via Spring Batch's FormatterLineAggregator. Using the format capabilities of String.format can allow you to generate fixed length records in a way that is standard across the JVM and framework independent.

这篇关于Spring-Batch:将对象写入固定长度的行吗?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！