JAVA STAX XML Parser (Working Perfectly) - an example xml is given in the code.

XML_Configuraion_Parser.java

import android.os.Bundle;

import java.io.ByteArrayInputStream;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Objects;
import java.util.Stack;

import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.events.Attribute;
import javax.xml.stream.events.EndElement;
import javax.xml.stream.events.StartElement;
import javax.xml.stream.events.XMLEvent;


/**
 * Created by Abdullah Riaz on 12/3/19.
 */
public class ConfigParser {

    private static final String TAG = MainActivity.class.getSimpleName();
    private static ConfigParser configParser;
    private boolean subBundleStarted = false;
    private Bundle staxBundle = new Bundle();
    private Stack<String> nameStack = new Stack<>();
    private Stack<Bundle> bundleStack = new Stack<>();

    private ConfigParser() {
    }

    public static ConfigParser getInstance() {
        if (configParser == null) {
            configParser = new ConfigParser();
        }
        return configParser;
    }

    public Bundle parseAndReturnBundle(String schema) {
        try {
            ByteArrayInputStream input = new ByteArrayInputStream(schema.getBytes("UTF-8"));

            XMLInputFactory factory = XMLInputFactory.newInstance();
            XMLEventReader eventReader = factory.createXMLEventReader(input);

            while (eventReader.hasNext()) {
                XMLEvent event = eventReader.nextEvent();

                switch (event.getEventType()) {

                    case XMLStreamConstants.START_ELEMENT:
                        StartElement startElement = event.asStartElement();
                        String qName = startElement.getName().getLocalPart();

                        if (qName.equalsIgnoreCase("parm")) {

                            Iterator<Attribute> attributes = startElement.getAttributes();
                            HashMap<String, String> hmap = new HashMap<>();

                            while (attributes.hasNext()) {
                                Attribute a = attributes.next();
                                hmap.put(a.getName().toString(), a.getValue());
                            }

                            if (Objects.equals(hmap.get("type"), "bundle")) {
                                nameStack.push(hmap.get("name"));
                                bundleStack.push(new Bundle());
                                subBundleStarted = true;
                            } else {
                                if (subBundleStarted) {
                                    addToLastBundle(hmap);
                                } else {
                                    addNormalValue(hmap);
                                }
                            }
                        }
                        break;


                    case XMLStreamConstants.END_ELEMENT:
                        EndElement endElement = event.asEndElement();
                        if (endElement.getName().getLocalPart().equalsIgnoreCase("bundle")) {
                            if (subBundleStarted && bundleStack.size() >= 2) {
                                addValuesToPreviousBundleInStacks();
                            } else {
                                staxBundle.putBundle(nameStack.pop(), bundleStack.pop());
                                if (bundleStack.empty() && nameStack.empty()) {
                                    subBundleStarted = false;
                                }
                            }
                        }
                        break;
                }
            }
            return staxBundle;
        } catch (
                Exception e) {
            e.printStackTrace();
        }
        return null;

    }

    private void addValuesToPreviousBundleInStacks() {
        Bundle b = bundleStack.pop();
        String s = nameStack.pop();

        Bundle toAddDataTo = bundleStack.pop();
        toAddDataTo.putBundle(s, b);
        bundleStack.push(toAddDataTo);
    }

    private void addToLastBundle(HashMap<String, String> hm) {
        Bundle b = bundleStack.pop();
        if (hm.get("type").equals("integer")) {
            b.putInt(hm.get("name"), Integer.parseInt(hm.get("value")));
        } else if (hm.get("type").equals("string")) {
            b.putString(hm.get("name"), hm.get("value"));
        }
        bundleStack.push(b);
    }

    private void addNormalValue(HashMap<String, String> hm) {
        if (hm.get("type").equals("integer")) {
            staxBundle.putInt(hm.get("name"), Integer.parseInt(hm.get("value")));
        } else if (hm.get("type").equals("string")) {
            staxBundle.putString(hm.get("name"), hm.get("value"));
        }
    }

}





// <characteristic type="com.airwatch.android.androidwork.app:com.innowi.checoutappconfig" uuid="8aac143a-03b6-4bb7-a94d-079f5a8b6399">
//     <parm name="SetupOEM" value="com.innowi" type="string" />
//     <parm name="Notification" type="bundle">
//         <bundle>
//             <parm name="AppNotification" type="bundle">
//                 <bundle>
//                     <parm name="EnableNotificationForPackages"  value="com.android.email , com.android.music" type="string" />
//                     <parm name="DisableNotificationForPackages"  value="com.android.contacts , com.android.settings" type="string" />
//                 </bundle>
//             </parm>
//         </bundle>
//     </parm>
// </characteristic>