JavaでXML文字列をparseしてObjectを取得する

ReadXML.java

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Element;
import org.xml.sax.SAXException;

public class ReadXML {
  public static void main(String... args) {
    var xml =
      "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?>\n" +
      "<people>\n" +
      "  <person age=\"20\" name=\"taro\"/>\n" +
      "  <person age=\"23\" name=\"hanako\"/>\n" +
      "  <person age=\"16\" name=\"foobar\"/>\n" +
      "</people>";
    try (InputStream is = new ByteArrayInputStream(xml.getBytes(StandardCharsets.UTF_8))) {
      var people = readXML(is);
      people.stream().forEach(person -> {
        System.out.println("name:"+person.name);
        System.out.println("age:"+person.age);
      });
    } catch (Exception e) {}
  }

  private static List<Person> readXML(InputStream inputStream)
      throws ParserConfigurationException, IOException, SAXException {
    var factory = DocumentBuilderFactory.newInstance();
    var builder = factory.newDocumentBuilder();
    var document = builder.parse(inputStream);
    var root = document.getDocumentElement();
    var people = root.getElementsByTagName("person");
    List<Person> result = new ArrayList<>();
    for (var i = 0; i < people.getLength(); i++) {
      var element = (Element) people.item(i);
      var name = element.getAttribute("name");
      var age = Integer.parseInt(element.getAttribute("age"));
      var person = new Person(name, age);
      result.add(person);
    }
    return result;
  }
}

class Person {
  final String name;
  final int age;
  Person(String name, int age) {
    this.name = name;
    this.age = age;
  }
}

z_README.md

前提条件

OpenJDK 16.0.1

実行方法

javac ReadXML.java
java ReadXML

実行結果

name:taro
age:20
name:hanako
age:23
name:foobar
age:16