<Test>
    <Item>
        <Group>
            <SubGroup test4="2018-09-01" test5="Y">

            </SubGroup>
        </Group>
    </Item>
    <Item>
        <Group>
            <SubGroup test="0" test2="t">

            </SubGroup>
            <SubGroup test3="0.0">

            </SubGroup>
        </Group>
    </Item>
</Test>

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

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;

public class UtilityMethods {
    public static byte getInt8(String input) {
        if (input == null || input.equals("")) {
            return 0;
        } else {
            return Byte.parseByte(input);
        }
    }
    public static short getInt16(String input) {
        if (input == null || input.equals("")) {
            return 0;
        } else {
            return Short.parseShort(input);
        }
    }
    public static int getInt32(String input) {
        if (input == null || input.equals("")) {
            return 0;
        } else {
            return Integer.parseInt(input);
        }
    }
    public static long getInt64(String input) {
        if (input == null || input.equals("")) {
            return 0L;
        } else {
            return Long.parseLong(input);
        }
    }
    public static Date getDate(String input) throws ParseException {
        if (input == null || input.equals("")) {
            return new Date();
        } else {
            return new SimpleDateFormat("yyyy-MM-dd").parse(input);
        }
    }
    public static double getDouble(String input) {
        if (input == null || input.equals("")) {
            return 0.0;
        } else {
            return Double.parseDouble(input);
        }
    }
    public static boolean getBoolean(String input) {
        if (input == null || input.equals("")) {
            return false;
        } else {
            return (input.equals("y") ? true : input.equals("yes") ? true : false);
        }
    }

    public static ArrayList<Node> getNodesByTagName(Node rootNode, String tagName) {
        ArrayList<Node> result = new ArrayList<>();
        NodeList subNodes = rootNode.getChildNodes();

        for (int i = 0; i < subNodes.getLength(); i++) {
            if (subNodes.item(i).getNodeName().equals(tagName)) {
                result.add(subNodes.item(i));
            }
        }

        return result;
    }

    public static String getAttrValue(Node attr) {
        if (attr == null) {
            return null;
        } else {
            return attr.getNodeValue();
        }
    }
}

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.Date;

public class SubGroup {
    private Date _test4;
    public Date get_test4() { return _test4; }
    public void set_test4(Date test4) { _test4 = test4; }

    private boolean _test5;
    public boolean get_test5() { return _test5; }
    public void set_test5(boolean test5) { _test5 = test5; }

    private String __Text;
    public String get__Text() { return __Text; }
    public void set__Text(String _Text) { __Text = _Text; }

    private String _test2;
    public String get_test2() { return _test2; }
    public void set_test2(String test2) { _test2 = test2; }

    private byte _test;
    public byte get_test() { return _test; }
    public void set_test(byte test) { _test = test; }

    private double _test3;
    public double get_test3() { return _test3; }
    public void set_test3(double test3) { _test3 = test3; }

    public void deserialize(String xml) throws ParserConfigurationException, IOException, SAXException, ParseException {
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder documentBuilder = factory.newDocumentBuilder();
        Document doc = documentBuilder.parse(new ByteArrayInputStream(xml.getBytes("utf-8")));
        Element root = doc.getDocumentElement();
        deserialize(doc.getElementsByTagName("SubGroup").item(0));
    }

    public void deserialize(Node myNode) throws ParseException {
        NodeList nodes;
        _test4 = UtilityMethods.getDate(UtilityMethods.getAttrValue(myNode.getAttributes().getNamedItem("test4")));
        _test5 = UtilityMethods.getBoolean(UtilityMethods.getAttrValue(myNode.getAttributes().getNamedItem("test5")));
        __Text = myNode.getTextContent();
        _test2 = UtilityMethods.getAttrValue(myNode.getAttributes().getNamedItem("test2"));
        _test = UtilityMethods.getInt8(UtilityMethods.getAttrValue(myNode.getAttributes().getNamedItem("test")));
        _test3 = UtilityMethods.getDouble(UtilityMethods.getAttrValue(myNode.getAttributes().getNamedItem("test3")));
    }
}

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.Date;

public class Group {
    private ArrayList<SubGroup> _subGroup;
    public ArrayList<SubGroup> get_subGroup() { return _subGroup; }
    public void set_subGroup(ArrayList<SubGroup> subGroup) { _subGroup = subGroup; }

    public void deserialize(String xml) throws ParserConfigurationException, IOException, SAXException, ParseException {
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder documentBuilder = factory.newDocumentBuilder();
        Document doc = documentBuilder.parse(new ByteArrayInputStream(xml.getBytes("utf-8")));
        Element root = doc.getDocumentElement();
        deserialize(doc.getElementsByTagName("Group").item(0));
    }

    public void deserialize(Node myNode) throws ParseException {
        NodeList nodes;
        _subGroup = new ArrayList<>();
        for (Node node : UtilityMethods.getNodesByTagName(myNode, "SubGroup")) {
            SubGroup item;
            item = new SubGroup();
            item.deserialize(node);
            _subGroup.add(item);
        }
    }
}

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.Date;

public class Item {
    private Group _group;
    public Group get_group() { return _group; }
    public void set_group(Group group) { _group = group; }

    public void deserialize(String xml) throws ParserConfigurationException, IOException, SAXException, ParseException {
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder documentBuilder = factory.newDocumentBuilder();
        Document doc = documentBuilder.parse(new ByteArrayInputStream(xml.getBytes("utf-8")));
        Element root = doc.getDocumentElement();
        deserialize(doc.getElementsByTagName("Item").item(0));
    }

    public void deserialize(Node myNode) throws ParseException {
        NodeList nodes;
        _group = new Group();
        _group.deserialize(UtilityMethods.getNodesByTagName(myNode, "Group").get(0));
    }
}

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.Date;

public class Test {
    private ArrayList<Item> _item;
    public ArrayList<Item> get_item() { return _item; }
    public void set_item(ArrayList<Item> item) { _item = item; }

    public void deserialize(String xml) throws ParserConfigurationException, IOException, SAXException, ParseException {
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder documentBuilder = factory.newDocumentBuilder();
        Document doc = documentBuilder.parse(new ByteArrayInputStream(xml.getBytes("utf-8")));
        Element root = doc.getDocumentElement();
        deserialize(doc.getElementsByTagName("Test").item(0));
    }

    public void deserialize(Node myNode) throws ParseException {
        NodeList nodes;
        _item = new ArrayList<>();
        for (Node node : UtilityMethods.getNodesByTagName(myNode, "Item")) {
            Item item;
            item = new Item();
            item.deserialize(node);
            _item.add(item);
        }
    }
}