Возврат карты из файла xml с использованием библиотеки Jaxb Java

Я пытаюсь вернуть карту непосредственно из файла XML. Я попробовал это, создав собственный адаптер, но проблема в том, что этот адаптер не получает входной параметр со значениями из XML.

Для справки, вот скриншоты проблемы.

Вот XML, который я пытаюсь разобрать

<?xml version = "1.0" encoding = "utf-8" standalone = "yes"?>
<GroupRoot>
    <Root>
        <Group>
            <UUID>ahsdlfkjadslkfjalkdsjflakjdslf</UUID>
            <Name>Root Group 1</Name>
            <Entry>
                <UUID>1212135454==</UUID>
                <String>
                    <Key>Notes</Key>
                    <Value>Notes from Manager</Value>
                </String>
                <String>
                    <Key>Item1</Key>
                    <Value>Item1Value</Value>
                </String>
                <String>
                    <Key>Item2</Key>
                    <Value>Item2Value</Value>
                </String>
                <String>
                    <Key>Item3</Key>
                    <Value>Item3Value</Value>
                </String>
                <String>
                    <Key>Item4</Key>
                    <Value>Item4Value</Value>
                </String>
            </Entry>
            <Entry>
                <UUID>45645466546546464==</UUID>
                <String>
                    <Key>Notes</Key>
                    <Value>Notes from Manager</Value>
                </String>
                <String>
                    <Key>Item1</Key>
                    <Value>Item1Value1</Value>
                </String>
                <String>
                    <Key>Item2</Key>
                    <Value>Item2Value1</Value>
                </String>
                <String>
                    <Key>Item3</Key>
                    <Value>Item3Value1</Value>
                </String>
                <String>
                    <Key>Item4</Key>
                    <Value>Item4Value1</Value>
                </String>
            </Entry>
        </Group>
    </Root>
</GroupRoot>

И вот мой Pojo's.

package com.parser.xml.model; 
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;

@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement(name = "GroupRoot")
public class KeePassFile {
    @XmlElement(name = "Root")
    public Root root;

}


package com.parser.xml.model; 
import java.util.List; 
import javax.xml.bind.annotation.XmlElement; 
public class Root {
    @XmlElement(name = "Group")
    public List<Group> groups;

}



package com.parser.xml.model;
import java.util.List;
import javax.xml.bind.annotation.XmlElement;
public class Group {

    @XmlElement(name = "Name")
    public String name;
    
    @XmlElement(name = "Group", nillable = false )
    public List<Group> subGroups;

    @XmlElement(name = "Entry",nillable = false)
    public List<Entry> entries;  
}


package com.parser.xml.model;

import java.util.HashMap;
import java.util.Map; 
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.adapters.XmlAdapter;
import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;

public class Entry {

    @XmlElement(name = "UUID")
    public String UUID;
    
    @XmlElement(name = "String")
    @XmlJavaTypeAdapter(StringMapperAdapter.class)
    public Map<String, String> MappedItems;

}


class MapperString { 
    @XmlElement(name = "Key")
    public String key; 
    @XmlElement(name = "Value")
    public String value;

    public MapperString() {
    }

    public MapperString(String key, String value) {
        this.key = key;
        this.value = value;
    }
 
}

class StringMapperAdapter extends XmlAdapter<MapperString[], Map<String, String>> {

    @Override
    public Map<String, String> unmarshal(MapperString[] v) throws Exception {
        HashMap<String, String> map = new HashMap<String, String>(); 
        for (MapperString element : v) {
            map.put(element.key, element.value);
        } 
        return map;
    }

    @Override
    public MapperString[] marshal(Map<String, String> v) throws Exception {
        // TODO Auto-generated method stub
        return null;
    }

}

Основной метод

package com.parser.xml;

import java.io.File;
import java.io.IOException; 
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller; 
import org.springframework.core.io.ClassPathResource; 
import com.parser.xml.model.KeePassFile;

public class RunAppMain {

    private static final String FILE_PATH = "TestXML.xml";
    
    public static void main(String[] Args) throws IOException, JAXBException
    {
        File resource = new ClassPathResource(FILE_PATH).getFile();
        JAXBContext context = JAXBContext.newInstance(KeePassFile.class);
        Unmarshaller un = context.createUnmarshaller();
        KeePassFile entry = (KeePassFile) un.unmarshal(resource);

        System.out.println("Testing");
    }
}