Firebase “mapped during deserialization, but got class java. Util. ArrayList”

I just tried firebase.com for my project on Android

The problem I get is that every time I take a snapshot and "throw" it back into POJO, I get this –

"Mapping during deserialization, but getting class java. Util. ArrayList" exception

I've been looking around, even using HashMap to change all my models without any ArrayList, and still get the same results

This is my model:

public class DevicesController {

        public DevicesCollection devices;
        public int numberOfport;
        String timerStatus;

        public DevicesController(){

            devices = new DevicesCollection();
            timerStatus = "UPDATED";
        }

        public DevicesController(int numberOfport){
            devices = new DevicesCollection();
            this.numberOfport = numberOfport;
            timerStatus = "UPDATED";
        }



        public ArrayList<Integer> getCurrentState(String in){
            ArrayList<Integer> currentState = new ArrayList<Integer>();
            for(int i = 0; i < numberOfport; i++){
                currentState.add(0);
            }
            Iterator it = this.getDevices().getAllDevices().entrySet().iterator();
            while (it.hasNext()) {
                Map.Entry pair = (Map.Entry) it.next();
                Device temp =(Device)pair.getValue();
                if(temp.isOn()){
                    currentState.set(temp.getPort(),1);
                }else if(!temp.isOn()){
                    currentState.set(temp.getPort(),0);
                }
            }

            return currentState;
        }


        public String getStringCurrentState(String in){
            ArrayList<Integer> currentState = getCurrentState("");
            String temp ="";
            for(int i = 0; i < currentState.size();i++){
                temp.concat(""+currentState.get(i));
            }
            return temp;
        }

        public void updateToDb(){
            Global.dbMRoot.child("devicesController").setValue(this);
        }

        public DevicesCollection getDevices() {
            return devices;
        }

        public int getNumberOfport() {
            return numberOfport;
        }

    }

    public class Category {
        public String name;
        public HashMap<String,String> devicesId;
        public DeviceAlarm categoryAlarm;

        public Category(){

        }

        public Category(String name) {
            devicesId = new HashMap<String,String>();
            this.name = name;
        }

        public void addDevice(Device dev){
            devicesId.put(dev.getId(),dev.getId());
        }


        public void removeDevice(Device dev){
            devicesId.remove(dev.getId());
        }

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }

        public HashMap<String,String> getDevicesId() {
            return devicesId;
        }

        public void setDevicesId(HashMap<String,String> devicesId) {
            this.devicesId = devicesId;
        }

    }

public class Device {

    public String id;
    public int port;
    public String name;
    public boolean on;
    public  DeviceAlarm alarm;

    public Device(){

    }


    public Device(String id,String name){
        this.id = id;
        this.name = name;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
        updateToDb();
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        updateToDb();
        this.name = name;
    }

    public boolean isOn() {
        return on;
    }

    public void setOn(boolean on) {
        updateToDb();
        this.on = on;
    }

    public void updateToDb(){
        Global.dbMRoot.child("devicesController").child("devices").child("allDevice").child(""+id).setValue(this);
    }
    public DeviceAlarm getTimer() {

        return alarm;
    }


    public int getPort() {

        return port;
    }

    public void setPort(int port) {
        updateToDb();
        this.port = port;
    }

    public DeviceAlarm getAlarm() {
        return alarm;
    }

    public void setAlarm(DeviceAlarm alarm) {
        Global.dbMRoot.child("devicesController").child("timerStatus").setValue("CHANGED");
        this.alarm = alarm;
        updateToDb();
    }

    public void setAlarm(boolean active,Calendar timeOn,Calendar timeOff) {
        Global.dbMRoot.child("devicesController").child("timerStatus").setValue("CHANGED");
        DeviceAlarm temp = new DeviceAlarm();
        temp.setTimeOff(timeOff);
        temp.setTimeOn(timeOn);
        this.alarm = temp;
        updateToDb();
    }
}


package com.lucerna.afgadev.lucerna_maincontroller.Models;

import com.lucerna.afgadev.lucerna_maincontroller.Global;

import java.util.ArrayList;
import java.util.HashMap;

/**
 * Created by aufa on 06/07/2016.
 */
public class DevicesCollection {

    public HashMap<String,Device> allDevices;
    public HashMap<String,Category>  categories;
    int lastId;

    public DevicesCollection(){
        categories = new HashMap<String,Category>();
        lastId = 0;
        allDevices = new HashMap<String,Device>();

    }

    public HashMap<String,Category> getCategories() {
        return categories;
    }

    public HashMap<String,Device> getAllDevices() {
        return allDevices;
    }

    public void addCategory(String name){
        categories.put(name,new Category(name));
    }

    public void removeCategory(String name) throws Exception{
        int index = -1;
        for(int i = 0; i< categories.size(); i++){
            if(categories.get(i).getName().equals(name)){
                index = 1;
            }
        }

        if(index == -1){
            throw new Exception("Category not found");
        }else{
            categories.remove(index);
        }

        updateToDB();

    }

    public void updateToDB(){
        Global.dbMRoot.child("devicesController").child("devices").setValue(this);
    }

    public Category findCategory(String name){
        Category temp = null;
        for(int i = 0; i< this.getCategories().size(); i++){
            if(this.getCategories().get(i).getName().equals(name)){
                temp = this.getCategories().get(i);
            }
        }
        return temp;
    }

    public void switchCategory(String name,boolean on){
        Category cat = findCategory(name);
        for(int i = 0; i < cat.getDevicesId().size();i++){

        }
    }


    public void addDevice(String name,int port){
        Device temp = new Device();
        temp.setPort(port);
        temp.setName(name);
        allDevices.put(""+lastId,temp);
        this.lastId++;
        Global.dbMRoot.child("devicesController").child("devices").child(""+lastId).setValue(allDevices.get(lastId));
    }

    public void removeDevice(int id){
        allDevices.remove(id);
        updateToDB();
    }

    public void setCategoryDevicesAlarm(DeviceAlarm da){

    }

}

Example JSON tree GDrive

I still don't know why it happened. I've rechecked to make sure none of them is ArrayList (I know firebase assumes that ArrayList is supported)

Thanks for all the comments and answers!

Solution

I have a partial answer, but I need Frank's expertise to explain the actual situation

Use version 9.2 0 runs the published code, and I observe that the HashMap of alldevices is stored as a JSON array:

public class DevicesCollection {

    public HashMap<String,Device> allDevices; <-- this is stored as array
    public HashMap<String,Category>  categories;
    int lastId;

This can be seen in the JSON released by AUFA:

{
  "devicesController" : {
    "devices" : {
      "allDevices" : [ { <-- note bracket
        "name" : "","on" : true,"port" : 0
      },{

This seems to be because the key of the alldevices element is an integer string This is the code to add an entry to the map of alldevices:

public void addDevice(String name,int port){
    Device temp = new Device();
    temp.setPort(port);
    temp.setName(name);
    allDevices.put(""+lastId,temp); <-- Note that lastId is an integer
    this.lastId++;
    Global.dbMRoot.child("devicesController").child("devices").child(""+lastId).setValue(allDevices.get(lastId));
}

If you modify this code to use a string key in a non integer format, for example:

allDevices.put("ID"+lastId,temp);

Then write the map as a map and use it

getValue(DevicesCollection.class);