custom file parser written in java needs improvement

Question

I've written parser in java for a structured binary file. Each field of the file starts the same way: it starts with a specific byte (introducer), the field length, field type and the field data. E.g. (in hex): 4200110A010203... Would be: Introducer: 42 field length: 0011 -> 17 bytes field type: 0A data: 010203...

But the way I've written the parser feels a bit cumbersome, especially the part about reading/interpreting the field data. And I wanted to ask you if there is a better way or even a standard approach to this. I mean this part:

    package example;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class Converter {
    private static final Map<String, Convert<Node, ?>> map = new HashMap<>();

    static {
        map.put("0A", Converter::getTypeA);
        map.put("0B", Converter::getTypeB);
        map.put("0C", Converter::getTypeC);
    }

    public static Node convert(Node node) {
        return (Node) map.get(node.getIdentifier()).convert(node);
    }

    private static Node getTypeA(Node node) {
        int id = Util.toInteger(new byte[]{node.getData()[4], node.getData()[5]});
        String value = Util.toString(node.getData(), 6);
        return new TypeA(node.getPosition(), node.getLength(), node.getIdentifier(), node.getData(), id, value);
    }

    private static Node getTypeB(Node node) {
        int id = Util.toInteger(new byte[]{node.getData()[4], node.getData()[5]});
        List<String> values = new ArrayList<>();
        int offset = 6;

        while(offset < node.getData().length) {
            int length = node.getData()[offset] & 0xFF;
            values.add(Util.toString(node.getData(), offset + 1, length));
            offset += 1 + length;
        }

        return new TypeB(node.getPosition(), node.getLength(), node.getIdentifier(), node.getData(), id, values);
    }

    private static Node getTypeC(Node node) {
        String value = Util.toString(node.getData(), 4, 8);
        byte[] data = new byte[node.getData().length - value.length()];

        return new TypeC(node.getPosition(), node.getLength(), node.getIdentifier(), node.getData(), value, data);
    }
}

Here is a complete example (can create files with random amount of data and then parse it back):