Разбор текстового файла с несколькими тегами и запись его в другой текстовый файл

Сначала вы должны сделать свой файл действительным xml:

<?xml version="1.0"?>
<rootnode>
    <parentnode xmlns="http://www.fpml.org/FpML-5/recordkeeping"
        fpmlVersion="5-5" xmlns:abcde="http://www.abcde.com/ext"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://www.abcde.com/ext /../xmls/XYZ/recordkeeping/abcde-ext.xsd">
        <Child1 Child1Scheme="http://www.google.com">1234566546</Child1>
        <Child1 Child1Scheme="http://www.fpml.org/coding-scheme/external/UNique">AbcdeXYZ-23243423</Child1>
        <country
            countryScheme="http://www.fpml.org/coding-scheme/external/country-identifier">1030253498</country>
        <state stateScheme="http://www.fpml.org/coding-scheme/external/state-identifier">23423423423</state>
    </parentnode>

    <parentnode xmlns="http://www.fpml.org/FpML-5/recordkeeping"
        fpmlVersion="5-5" xmlns:abcde="http://www.abcde.com/ext"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://www.abcde.com/ext /../xmls/XYZ/recordkeeping/abcde-ext.xsd">
        <Child1 Child1Scheme="http://www.google.com">1234566546</Child1>
        <Child1 Child1Scheme="http://www.fpml.org/coding-scheme/external/UNique">AbcdeXYZ-154555</Child1>
        <country
            countryScheme="http://www.fpml.org/coding-scheme/external/country-identifier">1030253498</country>
        <state stateScheme="http://www.fpml.org/coding-scheme/external/state-identifier">434343242</state>
    </parentnode>

    <parentnode xmlns="http://www.fpml.org/FpML-5/recordkeeping"
        fpmlVersion="5-5" xmlns:abcde="http://www.abcde.com/ext"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://www.abcde.com/ext /../xmls/XYZ/recordkeeping/abcde-ext.xsd">
        <Child1 Child1Scheme="http://www.google.com">1234566546</Child1>
        <Child1 Child1Scheme="http://www.fpml.org/coding-scheme/external/UNique">AbcdeXYZ-4566545</Child1>
        <country
            countryScheme="http://www.fpml.org/coding-scheme/external/country-identifier">1030253498</country>
        <state stateScheme="http://www.fpml.org/coding-scheme/external/state-identifier">2323232323</state>
    </parentnode>
</rootnode>

И тогда вы можете начать читать свой файл, просто проверьте его.

import java.io.File;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class ReadXMLFile {

    public static void main(String argv[]) {

        try {
            File fXmlFile = new File("file.xml");
            DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
            DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
            Document doc = dBuilder.parse(fXmlFile);

            doc.getDocumentElement().normalize();

            System.out.println("Root element :" + doc.getDocumentElement().getNodeName());

            NodeList nList = doc.getElementsByTagName("parentnode");

            for (int temp = 0; temp < nList.getLength(); temp++) {

                Node nNode = nList.item(temp);

                System.out.println("Current Element :" + nNode.getNodeName());

                if (nNode.getNodeType() == Node.ELEMENT_NODE) {
                    Element eElement = (Element) nNode;
                    System.out.println("Staff id : " + eElement.getElementsByTagName("Child1").item(0).getTextContent());
                    System.out.println("First Name : " + eElement.getElementsByTagName("Child1").item(0).getTextContent());
                    System.out.println("Last Name : " + eElement.getElementsByTagName("country").item(0).getTextContent());
                    System.out.println("Nick Name : " + eElement.getElementsByTagName("state").item(0).getTextContent());
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}