使用Java和XML模板处理固定宽度文件(JDOM)

<dependency>
    <groupId>org.jdom</groupId>
    <artifactId>jdom2</artifactId>
    <version>2.0.6</version>
</dependency>

implementation 'org.jdom:jdom2:2.0.6'

<template>
    <record>
        <field name="name" length="20"/>
        <field name="age" length="3"/>
        <field name="address" length="50"/>
    </record>
</template>

import org.jdom2.Document;
import org.jdom2.Element;
import org.jdom2.input.SAXBuilder;

import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.util.List;

public class FixedWidthProcessor {
    public static void main(String[] args) throws Exception {
        // 读取XML模板文件
        File templateFile = new File("path/to/template.xml");
        SAXBuilder builder = new SAXBuilder();
        InputStream inputStream = new FileInputStream(templateFile);
        Document document = builder.build(inputStream);
        Element rootElement = document.getRootElement();

        // 解析字段信息
        List<Element> fields = rootElement.getChild("record").getChildren("field");
        for (Element field : fields) {
            String name = field.getAttributeValue("name");
            int length = Integer.parseInt(field.getAttributeValue("length"));
            System.out.println("Field: " + name + ", Length: " + length);
        }
    }
}

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.StringWriter;
import org.jdom2.Document;
import org.jdom2.Element;
import org.jdom2.output.Format;
import org.jdom2.output.XMLOutputter;

public class FixedWidthProcessor {
    public static void main(String[] args) throws Exception {
        // 读取XML模板文件并解析字段信息（如上所示）

        // 处理固定宽度文件
        File fixedWidthFile = new File("path/to/fixed_width_file.txt");
        BufferedReader reader = new BufferedReader(new FileReader(fixedWidthFile));
        String line;
        StringWriter stringWriter = new StringWriter();
        XMLOutputter xmlOutputter = new XMLOutputter(Format.getPrettyFormat());

        while ((line = reader.readLine()) != null) {
            Element record = new Element("record");
            int currentPosition = 0;

            for (Element field : fields) {
                String name = field.getAttributeValue("name");
                int length = Integer.parseInt(field.getAttributeValue("length"));
                String value = line.substring(currentPosition, currentPosition + length).trim();
                currentPosition += length;

                Element fieldElement = new Element("field");
                fieldElement.setAttribute("name", name);
                fieldElement.setText(value);
                record.addContent(fieldElement);
            }

            Document document = new Document(record);
            xmlOutputter.output(document, stringWriter);
            System.out.println(stringWriter.toString());
            stringWriter.getBuffer().setLength(0); // 清空StringWriter
        }

        reader.close();
    }
}